This document provides a seismotectonic and seismic hazard analysis for the Simly Dam Project in Pakistan. It describes the geology, tectonics, and seismicity of the project area. A variety of faults pose seismic hazards, including the Jhelum Thrust Fault. The analysis examines historical earthquakes, conducts deterministic and probabilistic seismic hazard assessments, and estimates acceleration response spectra to determine the safety earthquake for dam design.
This document presents a seismic microzonation study of Gilgit, Nomal, and Naltar cities in northern Pakistan. It analyzes the geology, seismotectonics, and historical seismicity of the region to identify nine seismic zones with maximum earthquake potential of Mw 7.5-8.0. Probabilistic seismic hazard analysis is conducted using a composite earthquake catalog and six soil profile types. Peak ground acceleration values ranging from 0.24g to 0.25g are computed for different return periods, consistent with other projects in the area. Seismic microzones are delineated on maps for use in the Gilgit, Nomal, and Naltar Master Plan 2040. A micro seismic monitoring
Earthquake-prone Zonation of North Bengkulu Based on Peak Ground Acceleration...INFOGAIN PUBLICATION
We have done mapped earthquake-prone zonation of North Bengkulu, Indonesia, based on peak ground acceleration by kanai’s and Katayama’s formula. Twenty nine microtremor data have recorded by Digital portable Seismometer that installed in North Bengkulu regency. The result of HVSR analysis, we got resonance frequency and A0 which explained the condition of surface rocks. Peak ground acceleration on rock surface which applied local geology condition (dominant period of natural soil vibration). Based on A0 value, the risk of earthquakes in north Bengkulu was on moderate to high level because this area has relatively soft rock structure. Kanai's formula has correlation near 70.6% with Katayama's formula to showed PGA value on rock surface. Peak Ground acceleration of Kanai formula in North Bengkulu about 152,441 - 674,391 gal and based on Katayama formula between 35.2 gal until 51.3 gal. Based on PGA value, we estimated that North Bengkulu has on IV and IX of MMI scales. It meant that in North Bengkulu potential have heavy damage when an earthquake occurred. Distribution of PGA values based on the observation has correspond to effects earthquake of North Bengkulu at September 2007.
This document reassesses the locations and magnitudes of earthquakes in the Eastern Mediterranean and Middle East region from 1900 to 1999. The author compiled a catalog of over 5,000 earthquakes in the region, with a focus on 369 shallow earthquakes (depth less than 40 km) of magnitude 6.0 or greater. Many early earthquake locations and magnitudes from international catalogs were found to be inaccurate and have been re-evaluated based on macroseismic data and other studies. The catalog provides improved parameters for understanding seismic hazards and tectonics in the region.
1) The study develops a new attenuation relationship for Turkey by combining strong motion data from soil and rock sites.
2) To use the soil site data, boreholes were drilled at 64 soil sites to measure soil properties and remove soil amplification effects from the records.
3) Various regression models were tested using magnitude, distance, and peak ground acceleration to establish the new attenuation relationship for Turkey.
This document compares estimates of slip rates from long-term seismicity data to those calculated from GPS measurements for three regions in the eastern Mediterranean: the Gulf of Corinth, the Sea of Marmara, and the Dead Sea Fault Zone. It finds that slip rates calculated from historical earthquake data are generally comparable to those from GPS, while also quantifying uncertainties in the size of historical earthquakes. This permits a more reliable estimation of long-term seismic hazard for engineering purposes. The study focuses on areas with extensive long-term macroseismic information to facilitate this type of analysis.
An Integrated Study of Gravity and Magnetic Data to Determine Subsurface Stru...iosrjce
:The present study wascarried out to delineate the location, extension, trend and depth of subsurface
structures of Alamein area. To achieve this aim, the gravity and aeromagnetic data have been subjected to
different analytical techniques. The Fast Fourier Transform technique was used to separatethe residual
components from the regional ones. The resulted maps showed that the area was affected mainly bytheENE, EW,
WNWand NWtectonic trends. In addition, spectral analysis technique was applied on magnetic anomalies to
estimate the depth to basement surface, which varies from 3.03 in southern part to 7.24 Km in northern part.3DEulerdeconvloution
and tilt angle derivative techniques were carried out to detect the edges of magnetic sources
and to determine their depths.Correlation between them shows acoincidence between Euler solution and zero
lines of tilt angle map. A tentative basement structure map is constructed from the integration of these results
and geological information. This map shows alternative uplifted and downfaulted structure trending in the ENE,
NE and E-W directions. In addition, the NNW to NW strike-slip faults intersected them in later events. Finally,
2-D modeling technique was run on three gravity and magnetic profiles in the same location. Different drilled
wells and the constructed basement structure map support these modeled profiles. Theyshow an acidic basement
rocks. A general decreasing of Conrad discontinuity depths from about 20.5 km at southern part to 17.9 km at
northern part can be noticed. Moreover, the crustal thickness (depth to Moho discontinuity), varies between
31.5 and 28.5 km revealing visibly crustal stretching and thinning northerly
(a) Tectonic InSAR has provided insights into earthquake processes over the past 3 decades since its beginnings in the 1980s. Measurements from over 150 earthquakes have shown that ruptures can be more complex than expected and that surface slip is a poor indicator of slip at depth. Earthquakes have also been found to trigger other quakes dynamically or be structurally controlled.
(b) Interseismic strain accumulation along faults can now be measured using large InSAR data stacks, finding focused strain that may be constant throughout the earthquake cycle. However, uncertainties remain about applicability in all regions.
(c) Postseismic deformation and aseismic slip transients exhibit complex spatial patterns but overall decay
1) The document reassesses seismic hazard in the Marmara region of Turkey using new data on undersea fault segments and updated ground motion models.
2) Hazard maps show peak ground accelerations and spectral accelerations with 2% and 10% probabilities of exceedance in 50 years, indicating increased hazard across much of the region compared to previous maps.
3) The maximum predicted peak ground acceleration is 1.5g along fault segments of the North Anatolian fault extending into the Marmara Sea.
This document presents a seismic microzonation study of Gilgit, Nomal, and Naltar cities in northern Pakistan. It analyzes the geology, seismotectonics, and historical seismicity of the region to identify nine seismic zones with maximum earthquake potential of Mw 7.5-8.0. Probabilistic seismic hazard analysis is conducted using a composite earthquake catalog and six soil profile types. Peak ground acceleration values ranging from 0.24g to 0.25g are computed for different return periods, consistent with other projects in the area. Seismic microzones are delineated on maps for use in the Gilgit, Nomal, and Naltar Master Plan 2040. A micro seismic monitoring
Earthquake-prone Zonation of North Bengkulu Based on Peak Ground Acceleration...INFOGAIN PUBLICATION
We have done mapped earthquake-prone zonation of North Bengkulu, Indonesia, based on peak ground acceleration by kanai’s and Katayama’s formula. Twenty nine microtremor data have recorded by Digital portable Seismometer that installed in North Bengkulu regency. The result of HVSR analysis, we got resonance frequency and A0 which explained the condition of surface rocks. Peak ground acceleration on rock surface which applied local geology condition (dominant period of natural soil vibration). Based on A0 value, the risk of earthquakes in north Bengkulu was on moderate to high level because this area has relatively soft rock structure. Kanai's formula has correlation near 70.6% with Katayama's formula to showed PGA value on rock surface. Peak Ground acceleration of Kanai formula in North Bengkulu about 152,441 - 674,391 gal and based on Katayama formula between 35.2 gal until 51.3 gal. Based on PGA value, we estimated that North Bengkulu has on IV and IX of MMI scales. It meant that in North Bengkulu potential have heavy damage when an earthquake occurred. Distribution of PGA values based on the observation has correspond to effects earthquake of North Bengkulu at September 2007.
This document reassesses the locations and magnitudes of earthquakes in the Eastern Mediterranean and Middle East region from 1900 to 1999. The author compiled a catalog of over 5,000 earthquakes in the region, with a focus on 369 shallow earthquakes (depth less than 40 km) of magnitude 6.0 or greater. Many early earthquake locations and magnitudes from international catalogs were found to be inaccurate and have been re-evaluated based on macroseismic data and other studies. The catalog provides improved parameters for understanding seismic hazards and tectonics in the region.
1) The study develops a new attenuation relationship for Turkey by combining strong motion data from soil and rock sites.
2) To use the soil site data, boreholes were drilled at 64 soil sites to measure soil properties and remove soil amplification effects from the records.
3) Various regression models were tested using magnitude, distance, and peak ground acceleration to establish the new attenuation relationship for Turkey.
This document compares estimates of slip rates from long-term seismicity data to those calculated from GPS measurements for three regions in the eastern Mediterranean: the Gulf of Corinth, the Sea of Marmara, and the Dead Sea Fault Zone. It finds that slip rates calculated from historical earthquake data are generally comparable to those from GPS, while also quantifying uncertainties in the size of historical earthquakes. This permits a more reliable estimation of long-term seismic hazard for engineering purposes. The study focuses on areas with extensive long-term macroseismic information to facilitate this type of analysis.
An Integrated Study of Gravity and Magnetic Data to Determine Subsurface Stru...iosrjce
:The present study wascarried out to delineate the location, extension, trend and depth of subsurface
structures of Alamein area. To achieve this aim, the gravity and aeromagnetic data have been subjected to
different analytical techniques. The Fast Fourier Transform technique was used to separatethe residual
components from the regional ones. The resulted maps showed that the area was affected mainly bytheENE, EW,
WNWand NWtectonic trends. In addition, spectral analysis technique was applied on magnetic anomalies to
estimate the depth to basement surface, which varies from 3.03 in southern part to 7.24 Km in northern part.3DEulerdeconvloution
and tilt angle derivative techniques were carried out to detect the edges of magnetic sources
and to determine their depths.Correlation between them shows acoincidence between Euler solution and zero
lines of tilt angle map. A tentative basement structure map is constructed from the integration of these results
and geological information. This map shows alternative uplifted and downfaulted structure trending in the ENE,
NE and E-W directions. In addition, the NNW to NW strike-slip faults intersected them in later events. Finally,
2-D modeling technique was run on three gravity and magnetic profiles in the same location. Different drilled
wells and the constructed basement structure map support these modeled profiles. Theyshow an acidic basement
rocks. A general decreasing of Conrad discontinuity depths from about 20.5 km at southern part to 17.9 km at
northern part can be noticed. Moreover, the crustal thickness (depth to Moho discontinuity), varies between
31.5 and 28.5 km revealing visibly crustal stretching and thinning northerly
(a) Tectonic InSAR has provided insights into earthquake processes over the past 3 decades since its beginnings in the 1980s. Measurements from over 150 earthquakes have shown that ruptures can be more complex than expected and that surface slip is a poor indicator of slip at depth. Earthquakes have also been found to trigger other quakes dynamically or be structurally controlled.
(b) Interseismic strain accumulation along faults can now be measured using large InSAR data stacks, finding focused strain that may be constant throughout the earthquake cycle. However, uncertainties remain about applicability in all regions.
(c) Postseismic deformation and aseismic slip transients exhibit complex spatial patterns but overall decay
1) The document reassesses seismic hazard in the Marmara region of Turkey using new data on undersea fault segments and updated ground motion models.
2) Hazard maps show peak ground accelerations and spectral accelerations with 2% and 10% probabilities of exceedance in 50 years, indicating increased hazard across much of the region compared to previous maps.
3) The maximum predicted peak ground acceleration is 1.5g along fault segments of the North Anatolian fault extending into the Marmara Sea.
The document describes the development of site-dependent design spectra for Turkey based on analysis of 112 strong ground motion records from 57 earthquakes between 1976-2003. The spectra account for magnitude, distance, and local site conditions. Three site categories were defined based on shear wave velocity: rock, soil, and soft soil. Attenuation relationships were developed to predict peak ground acceleration and spectral acceleration based on magnitude, distance, and site category. The derived spectra were compared to other design spectra and found to be generally consistent while providing site-specific information not available in other codes.
This document describes a study that uses integrated digital imaging analysis methods on ASTER satellite data to develop a site characterization map for the Islamabad, Pakistan region. Pixel-based and object-oriented analysis methods are used to characterize detailed geomorphology and geology from ASTER imagery, including stereo-correlated digital elevation models and visible to thermal infrared spectra. The resulting map classifies geomorphic units as mountain, piedmont, or basin terrain and identifies local geologic units of limestone and sandstone. Shear-wave velocity ranges are assigned to each unit based on established correlations. The map provides a basis for incorporating site response into seismic hazard assessments for Islamabad while demonstrating the potential of remote sensing for site characterization in regions with
The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock loc...Gus Alex Reyes
The subduction zone off the Nicaragua
coastline has been the site of several large
earthquakes in the past decades, including
the 1992 tsunami earthquake that was
anomalous in the size of the tsunami relative
to moment release [Kanamori and
Kikuchi, 1993]. As a focus site for both
the MARGINS-SEIZE and SubFac initiatives,
it is an area of keen interest for
scientists interested in earthquake rupture
and volcanic processes.
Seismic Risk Assessment and Hazard mapping in NepalPrinceShahabkhan
Assalamualikum
This presentation is about" Seismic Risk Assessment and Hazard mapping in Nepal" and it is related to Hazard and Disaster management Subject.
The document summarizes a study that analyzed aeromagnetic anomalies in the Marmara region of northwest Turkey and their spatial correlation with local faults. The study utilized reduction to the pole transformation and second vertical derivative methods on aeromagnetic data. These analyses revealed alignments correlating with major faults in the region, including the Northern Boundary, Yalova, Armutlu, Imrali, and Edincik faults. The authors identify these collectively as the Main Fault Zone, which exceeds 300 km in length and poses a high risk for strong earthquakes based on gaps in recent seismic activity.
This document evaluates the seismic risk in Istanbul, Turkey. It finds that ground motions from a future earthquake near Istanbul would likely be comparable to those that devastated Düzce, Turkey in 1999. The structures of buildings in Istanbul are found to have a similar vulnerability as those in Düzce based on structural analysis. Given these similarities, the document projects that an earthquake near Istanbul could cause severe damage or collapse to approximately 250,000 buildings. It concludes that leaving the vulnerable buildings unchanged and only planning emergency response is not a sufficient strategy for Istanbul.
1) Simple 2D magnetic and gravity models were constructed for the Marmara Sea region using geophysical data.
2) The magnetic models show fault-related magnetic bodies extending from the sea floor to a depth of 14.5 km.
3) The gravity model is consistent with previous seismic maps and shows horst-like structures in the central ridge, suggesting the area acts as a restraining bend.
This document summarizes a tomographic seismic velocity study of the shallow crust in the Eastern Marmara region of Turkey. Seismic refraction data was collected along a 120 km profile crossing active fault zones. Tomographic inversion of first-arrival travel times produced a 2D velocity model down to 7 km depth showing significant velocity heterogeneity. Areas of high and low seismic velocity correlate well with the locations of aftershocks from the 1999 Izmit earthquake, suggesting a relationship between crustal structure and seismicity along fault zones in the region.
The Border Zone between the Arabian and Turkish plates has been unusually quiet seismically during the 20th century, with only three earthquakes above magnitude 6.6. However, examining historical earthquake data from the past few centuries shows that this recent quiescence is atypical of long-term behavior in the zone. Specifically, 15 large earthquakes with magnitudes over 6.6 are documented in the region between 1500-1905, indicating the 20th century has experienced an anomalous lack of seismic activity when compared to previous centuries. This suggests that short-term seismic data alone are not sufficient to reliably assess earthquake hazards in the region.
Probabilistic seismic hazard assessment in the vicinity of MBT and MCT in wes...inventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document summarizes recent research on the North Anatolian Fault in Turkey. Key points include:
- The fault has been active since the Miocene period 15 million years ago, with an average slip rate of 0.5-0.7 cm/year. The recent slip rate associated with earthquakes is 1-2 cm/year.
- Stress drops from earthquakes on the fault are not dependent on magnitude for quakes above M7. Relationships between seismic moment and fault area differ for large and small quakes.
- Future research needs include more detailed mapping, paleogeographic reconstruction, geochemical correlations across the fault, seismic studies, and geodetic monitoring for earthquake prediction.
Presentation on Structural analysis of Slump Folds from Neogene Deep-marine Slope - Shallow Marine Deposits to get some trace of India-Asia subduction and Collision.
This document presents a preliminary seismic microzonation map of Sivas city in Turkey based on microtremor measurements. The researchers conducted microtremor measurements at 114 sites across the city to determine the dominant periods of vibration in the sediments. They divided the city into four zones based on variations in dominant periods, which likely correspond to different levels of seismic hazard. Refraction microtremor measurements along two profiles validated the microzonation map, but further studies are needed to fully characterize seismic hazards in the area.
Marmara ve İstanbul için ayrı ayrı 2 senaryo yapılmış. Coulomb Stress etkisi önemli ölçüde deprem olasılığını yükseltiyor. Özellikle, KAFZ boyunca meydana gelen depremlerin yüzey kırıklarının Dünya'da ki benzer büyük depremlerin yüzey kırıklarından oldukça farklı ve büyük.
This document discusses various topics related to seismic design, including:
- Seismicity and plate tectonics, which show that most earthquakes occur at plate boundaries.
- Different types of earthquakes like intraplate and reservoir-induced seismicity. Reservoir-induced seismicity can occur due to rapid reservoir filling or fluctuations in water level.
- Effects of soil conditions like basin effects that can amplify seismic ground motions. Soft soils in large basins like Mexico City significantly amplified motions from a distant earthquake, contributing to extensive damage.
- Key geotechnical aspects impacting seismic design like liquefaction, plasticity index, and shear wave velocity and how they relate to soil behavior during earthquakes
This document provides a summary of revisions made to the Indian Standard 1893 regarding criteria for earthquake resistant design of structures. Some key changes include:
1) The seismic zone map was revised to have 4 zones instead of 5, merging Zone I into Zone II. Zone factors were also changed to reflect realistic peak ground accelerations.
2) Response spectra are now specified for 3 foundation types: rock, medium soil, and soft soil.
3) Empirical expressions for estimating building period were revised.
4) The concept of a response reduction factor was introduced to account for energy dissipation in ductile structures.
The earthquake along the Pernicana fault in Italy on April 3, 2010 was analyzed using satellite and ground deformation data. Satellite radar images showed up to 23 cm of ground displacement near the fault. Leveling surveys found up to 70 mm of vertical displacement across the fault. Integrating these data using SISTEM modeling revealed maximum eastward and vertical displacements of 370 mm and 70 mm along the fault. Fault modeling indicated shallow faulting between 100-250m depth with left-lateral and normal motion on the fault consistent with the observed displacements.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Site-dependent Spectra: Ground Motion Records in TurkeyAli Osman Öncel
This document discusses site-dependent ground motion spectra derived from 112 strong motion records from 57 earthquakes in Turkey between 1976-2003. The authors develop horizontal attenuation relationships and compare the derived spectral shapes to those in Turkish and UBC seismic codes. They find that corner periods are consistent with UBC but the Turkish code yields wider constant spectral acceleration plateaus. The results allow generating site-distance-magnitude specific design spectra for probabilistic seismic hazard assessments in Turkey.
Geotectonic setting of Singapore and SE AsiaKYI KHIN
1) Singapore is located on the Sunda Plate near the boundary with the Indo-Australian Plate, which has experienced subduction, volcanism, and basin formation over geologic time due to the opening and closing of surrounding ocean basins.
2) Two major tectonic activities can cause major earthquakes in the region - subduction of the Indo-Australian Plate under the Sunda Plate, and strike-slip movement along the Sumatra Fault.
3) The worst earthquake scenarios modeled are a Mw 9.5 subduction earthquake 600 km from Singapore or a Mw 7.8 earthquake on the Sumatra Fault 400 km away, demonstrating Singapore's vulnerability to seismic activity in the region.
This document provides a seismic data interpretation report for the Diamer Basha Dam project in Pakistan from 2007-2012. It summarizes previous seismic studies conducted during project feasibility which recommended design earthquake parameters. It then discusses the seismotectonic setting of the project area, including major active faults like the Main Mantle Thrust, Main Karakoram Thrust, and Kohistan faults. Microseismic monitoring data from an on-site network is presented, showing seismicity patterns and magnitudes in the project region. The conclusion is that while several active faults are present near the site, no active faults were observed in the immediate vicinity based on the available data and studies.
The document discusses a proposed 700m sewage tunnel connecting the Reservoir and Fawkner areas of Melbourne to the Northern Diversion Sewer. It analyzes borehole logs from the area to characterize the basalt rock mass where the tunnel will be constructed. Classification systems like the Rock Mass Rating and Q System are used to evaluate parameters like rock strength, discontinuity spacing and condition, and groundwater, in order to assess the rock mass and inform construction recommendations.
The document describes the development of site-dependent design spectra for Turkey based on analysis of 112 strong ground motion records from 57 earthquakes between 1976-2003. The spectra account for magnitude, distance, and local site conditions. Three site categories were defined based on shear wave velocity: rock, soil, and soft soil. Attenuation relationships were developed to predict peak ground acceleration and spectral acceleration based on magnitude, distance, and site category. The derived spectra were compared to other design spectra and found to be generally consistent while providing site-specific information not available in other codes.
This document describes a study that uses integrated digital imaging analysis methods on ASTER satellite data to develop a site characterization map for the Islamabad, Pakistan region. Pixel-based and object-oriented analysis methods are used to characterize detailed geomorphology and geology from ASTER imagery, including stereo-correlated digital elevation models and visible to thermal infrared spectra. The resulting map classifies geomorphic units as mountain, piedmont, or basin terrain and identifies local geologic units of limestone and sandstone. Shear-wave velocity ranges are assigned to each unit based on established correlations. The map provides a basis for incorporating site response into seismic hazard assessments for Islamabad while demonstrating the potential of remote sensing for site characterization in regions with
The October 2004 Mw=7.1 Nicaragua earthquake: Rupture process, aftershock loc...Gus Alex Reyes
The subduction zone off the Nicaragua
coastline has been the site of several large
earthquakes in the past decades, including
the 1992 tsunami earthquake that was
anomalous in the size of the tsunami relative
to moment release [Kanamori and
Kikuchi, 1993]. As a focus site for both
the MARGINS-SEIZE and SubFac initiatives,
it is an area of keen interest for
scientists interested in earthquake rupture
and volcanic processes.
Seismic Risk Assessment and Hazard mapping in NepalPrinceShahabkhan
Assalamualikum
This presentation is about" Seismic Risk Assessment and Hazard mapping in Nepal" and it is related to Hazard and Disaster management Subject.
The document summarizes a study that analyzed aeromagnetic anomalies in the Marmara region of northwest Turkey and their spatial correlation with local faults. The study utilized reduction to the pole transformation and second vertical derivative methods on aeromagnetic data. These analyses revealed alignments correlating with major faults in the region, including the Northern Boundary, Yalova, Armutlu, Imrali, and Edincik faults. The authors identify these collectively as the Main Fault Zone, which exceeds 300 km in length and poses a high risk for strong earthquakes based on gaps in recent seismic activity.
This document evaluates the seismic risk in Istanbul, Turkey. It finds that ground motions from a future earthquake near Istanbul would likely be comparable to those that devastated Düzce, Turkey in 1999. The structures of buildings in Istanbul are found to have a similar vulnerability as those in Düzce based on structural analysis. Given these similarities, the document projects that an earthquake near Istanbul could cause severe damage or collapse to approximately 250,000 buildings. It concludes that leaving the vulnerable buildings unchanged and only planning emergency response is not a sufficient strategy for Istanbul.
1) Simple 2D magnetic and gravity models were constructed for the Marmara Sea region using geophysical data.
2) The magnetic models show fault-related magnetic bodies extending from the sea floor to a depth of 14.5 km.
3) The gravity model is consistent with previous seismic maps and shows horst-like structures in the central ridge, suggesting the area acts as a restraining bend.
This document summarizes a tomographic seismic velocity study of the shallow crust in the Eastern Marmara region of Turkey. Seismic refraction data was collected along a 120 km profile crossing active fault zones. Tomographic inversion of first-arrival travel times produced a 2D velocity model down to 7 km depth showing significant velocity heterogeneity. Areas of high and low seismic velocity correlate well with the locations of aftershocks from the 1999 Izmit earthquake, suggesting a relationship between crustal structure and seismicity along fault zones in the region.
The Border Zone between the Arabian and Turkish plates has been unusually quiet seismically during the 20th century, with only three earthquakes above magnitude 6.6. However, examining historical earthquake data from the past few centuries shows that this recent quiescence is atypical of long-term behavior in the zone. Specifically, 15 large earthquakes with magnitudes over 6.6 are documented in the region between 1500-1905, indicating the 20th century has experienced an anomalous lack of seismic activity when compared to previous centuries. This suggests that short-term seismic data alone are not sufficient to reliably assess earthquake hazards in the region.
Probabilistic seismic hazard assessment in the vicinity of MBT and MCT in wes...inventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document summarizes recent research on the North Anatolian Fault in Turkey. Key points include:
- The fault has been active since the Miocene period 15 million years ago, with an average slip rate of 0.5-0.7 cm/year. The recent slip rate associated with earthquakes is 1-2 cm/year.
- Stress drops from earthquakes on the fault are not dependent on magnitude for quakes above M7. Relationships between seismic moment and fault area differ for large and small quakes.
- Future research needs include more detailed mapping, paleogeographic reconstruction, geochemical correlations across the fault, seismic studies, and geodetic monitoring for earthquake prediction.
Presentation on Structural analysis of Slump Folds from Neogene Deep-marine Slope - Shallow Marine Deposits to get some trace of India-Asia subduction and Collision.
This document presents a preliminary seismic microzonation map of Sivas city in Turkey based on microtremor measurements. The researchers conducted microtremor measurements at 114 sites across the city to determine the dominant periods of vibration in the sediments. They divided the city into four zones based on variations in dominant periods, which likely correspond to different levels of seismic hazard. Refraction microtremor measurements along two profiles validated the microzonation map, but further studies are needed to fully characterize seismic hazards in the area.
Marmara ve İstanbul için ayrı ayrı 2 senaryo yapılmış. Coulomb Stress etkisi önemli ölçüde deprem olasılığını yükseltiyor. Özellikle, KAFZ boyunca meydana gelen depremlerin yüzey kırıklarının Dünya'da ki benzer büyük depremlerin yüzey kırıklarından oldukça farklı ve büyük.
This document discusses various topics related to seismic design, including:
- Seismicity and plate tectonics, which show that most earthquakes occur at plate boundaries.
- Different types of earthquakes like intraplate and reservoir-induced seismicity. Reservoir-induced seismicity can occur due to rapid reservoir filling or fluctuations in water level.
- Effects of soil conditions like basin effects that can amplify seismic ground motions. Soft soils in large basins like Mexico City significantly amplified motions from a distant earthquake, contributing to extensive damage.
- Key geotechnical aspects impacting seismic design like liquefaction, plasticity index, and shear wave velocity and how they relate to soil behavior during earthquakes
This document provides a summary of revisions made to the Indian Standard 1893 regarding criteria for earthquake resistant design of structures. Some key changes include:
1) The seismic zone map was revised to have 4 zones instead of 5, merging Zone I into Zone II. Zone factors were also changed to reflect realistic peak ground accelerations.
2) Response spectra are now specified for 3 foundation types: rock, medium soil, and soft soil.
3) Empirical expressions for estimating building period were revised.
4) The concept of a response reduction factor was introduced to account for energy dissipation in ductile structures.
The earthquake along the Pernicana fault in Italy on April 3, 2010 was analyzed using satellite and ground deformation data. Satellite radar images showed up to 23 cm of ground displacement near the fault. Leveling surveys found up to 70 mm of vertical displacement across the fault. Integrating these data using SISTEM modeling revealed maximum eastward and vertical displacements of 370 mm and 70 mm along the fault. Fault modeling indicated shallow faulting between 100-250m depth with left-lateral and normal motion on the fault consistent with the observed displacements.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Site-dependent Spectra: Ground Motion Records in TurkeyAli Osman Öncel
This document discusses site-dependent ground motion spectra derived from 112 strong motion records from 57 earthquakes in Turkey between 1976-2003. The authors develop horizontal attenuation relationships and compare the derived spectral shapes to those in Turkish and UBC seismic codes. They find that corner periods are consistent with UBC but the Turkish code yields wider constant spectral acceleration plateaus. The results allow generating site-distance-magnitude specific design spectra for probabilistic seismic hazard assessments in Turkey.
Geotectonic setting of Singapore and SE AsiaKYI KHIN
1) Singapore is located on the Sunda Plate near the boundary with the Indo-Australian Plate, which has experienced subduction, volcanism, and basin formation over geologic time due to the opening and closing of surrounding ocean basins.
2) Two major tectonic activities can cause major earthquakes in the region - subduction of the Indo-Australian Plate under the Sunda Plate, and strike-slip movement along the Sumatra Fault.
3) The worst earthquake scenarios modeled are a Mw 9.5 subduction earthquake 600 km from Singapore or a Mw 7.8 earthquake on the Sumatra Fault 400 km away, demonstrating Singapore's vulnerability to seismic activity in the region.
This document provides a seismic data interpretation report for the Diamer Basha Dam project in Pakistan from 2007-2012. It summarizes previous seismic studies conducted during project feasibility which recommended design earthquake parameters. It then discusses the seismotectonic setting of the project area, including major active faults like the Main Mantle Thrust, Main Karakoram Thrust, and Kohistan faults. Microseismic monitoring data from an on-site network is presented, showing seismicity patterns and magnitudes in the project region. The conclusion is that while several active faults are present near the site, no active faults were observed in the immediate vicinity based on the available data and studies.
The document discusses a proposed 700m sewage tunnel connecting the Reservoir and Fawkner areas of Melbourne to the Northern Diversion Sewer. It analyzes borehole logs from the area to characterize the basalt rock mass where the tunnel will be constructed. Classification systems like the Rock Mass Rating and Q System are used to evaluate parameters like rock strength, discontinuity spacing and condition, and groundwater, in order to assess the rock mass and inform construction recommendations.
The document provides a seismic data report for the Diamer Basha Dam Project covering January 1, 2012 to March 31, 2012. A total of 790 micro seismic events were located within 250km of the project site, with magnitudes between 0.0-5.8 and depths between 0-359.94km. 347 events were located within 100km of the site, with magnitudes 0.0-3.8 and depths 0-213.29km. Many events were located along faults mapped in previous neotectonics studies. The project site is located on the Kohistan Island Arc between the Main Karakoram Thrust and Main Mantle Thrust in a seismically active region along the collision zone
This document summarizes an earthquake that occurred in Sikkim, India in 2011. It discusses the magnitude of the earthquake at 6.9 and the aftershocks that followed throughout the night. It then provides definitions and explanations of key earthquake terms like focus, epicenter, fault, body waves and surface waves. Finally, it discusses the impacts of the earthquake in Sikkim and surrounding areas, including damage to buildings and roads, relief efforts provided, and studies conducted on dams and infrastructure.
The document describes the geology of the Betics Cordillera mountain range in southern Spain. It discusses the formation of the range through the rifting of Pangaea and the collision of Africa and Iberia. The Betics Cordillera can be divided into External Zones comprising folded sediments from continental rifting, and Internal Zones containing metamorphic rocks from the Late Cretaceous to Early Tertiary collision. Key features include evaporite deposits from early rifting, ophiolite complexes indicating oceanic crust, and Neogene basins containing evidence of turbidity currents and gypsum deposits recording changing environmental conditions.
This document provides an introduction to earthquake resistant design. It discusses how adopting building codes with seismic design and construction requirements helps communities protect citizens from earthquakes. It also describes methods to construct earthquake resistant buildings, such as using base isolators with layers of rubber and steel to absorb earthquake energy. Engineers aim to increase structures' natural periods, install energy dissipating devices, and use reinforcement like securing buildings to foundations. The document outlines the basics of earthquake engineering and importance of minimizing earthquake impacts. It discusses seismic waves, seismographs, potential ground failures, and indirect quake effects like tsunamis. Historical earthquakes are also summarized along with the causes and forces of earthquakes.
Dr. Ram Ben-David presented on two mining projects and two geoengineering projects from his portfolio. For the Sakassou gold exploration project in Cote d'Ivoire, he discussed the regional geology, exploration phases including soil and trench sampling, and initial results. For the Shefa Yamim exploration project in Israel, he outlined the exploration licenses, his role as chief geologist developing programs, and some regional geology. He also presented on coastal cliff stability projects in Israel examining geological problems and engineering solutions, and a large underground parking project in Jerusalem where he provided geological supervision of tunneling.
1) The document describes the geological evolution of the Porcupine Basin offshore Ireland, from initial Late Jurassic rifting through Early Cretaceous hyperextension and thermal subsidence.
2) During the Late Jurassic, rifting created fault-bounded sub-basins that were filled by fluvial-deltaic and later marine sediments. In the Early Cretaceous, the basin transitioned to hyperextension, forming structurally rotated depocentres perched on basin flanks.
3) Major unconformities reflect periods of erosion and mass wasting during basin evolution. Younger Cretaceous strata onlapped and buried the older rotated sequences.
After emerging from the resources wilderness thanks to its world-class geology and industry-friendly government policies, South Australia is now a leader in Australian mining and hydrocarbon developments over the last decade.
In little more than a decade the State has gone from four operating mines to more than 20 and is rated Australia’s second most popular exploration destination.
With a comprehensive review of the Mining Act under way, the State’s attractiveness as a place for resources and energy investment is expected to be strengthened.
South Australia is now a leader in the exploration for next generation energy sources with companies such as Santos and BP leading the charge, while initiatives such as the Government’s Copper Strategy – designed to treble annual copper production to 1 mtpa – is set to establish the State as one of the world’s premier producers of the red metal.
In the energy space, uranium and nuclear energy is another area of keen interest, with the South Australian Government initiating a Royal Commission into Participation in the Nuclear Fuel Cycle in 2016.
The State has become synonymous with innovation, cutting-edge development and a remarkable rate of discovery. From uranium prospects, to geothermal energy and the buoyant hydrocarbons sector, South Australia is now a leader in the exploration for next generation energy sources.
With full support from the Department of State Development, the South Australian Resources and Energy Investment Conference will continue to showcase this burgeoning sector in 2017. From copper plays in the Gawler Craton, to iron ore and graphite developments on the Eyre Peninsula and the emergence of the State as a new hydrocarbon frontier, South Australia’s resources potential is at last being fully recognised.
The conference will feature the success stories and emerging players in the State from both minerals and oil and gas and will also tackle thorny industry issues such as infrastructure, corporate social responsibility and the future of the Woomera Prohibited Area.
The document discusses plate tectonics and the movement of tectonic plates. It describes the three main types of plate boundaries - destructive, constructive, and conservative. At destructive boundaries, one plate is subducted under another, leading to features like trenches and volcanoes. At constructive boundaries, plates move apart and new crust is formed via volcanism and rifting. Conservative boundaries involve plates sliding past each other. Overall, the document provides an overview of plate tectonics theory and the associated landforms generated at different plate boundary types.
This document summarizes a study that analyzed zircon grains from a sandstone sample of the Quartoo Sand Member in South Australia using laser ablation-inductively coupled plasma mass spectrometry to determine its sedimentary provenance. The Quartoo Sand Member is part of the Eocene Muloowurtie Formation within the St Vincent Basin. The study found multiple age populations of zircons indicating the sand originated from various geological provinces. Determining the provenance helps understand the nature and extent of the sedimentary cover in relation to the underlying basement geology near the Hillside Cu-Au deposit.
This document summarizes research on predicting volcanic rock fractures in the Yingcheng Formation in the Songliao Basin in China. Three methods were used to predict fractures: coherence analysis, ant colony algorithm, and curvature attributes applied to post-stack seismic data. Coherence identified low coherence zones indicating possible fractures. Ant colony algorithm clearly showed vertically oriented fractures trending NNE, NE, and NS. Curvature attributes identified zones of large curvature values coinciding with predicted fracture belts. Well data including FMI logs confirmed the fracture types and distributions matched the predictions. The methods effectively predicted the distribution of three fracture systems that are important for hydrocarbon exploration in the region.
The document summarizes information about the 2005 Mw 7.7 Kashmir-Hazara earthquake in northern Pakistan. Key points:
- The earthquake ruptured the active Jhelum Thrust fault, killing over 100,000 people. It was one of the most destructive earthquakes along the Himalayan arc.
- The earthquake provided new insights into the regional tectonic framework and origin of the Kashmir-Hazara Syntaxis. The Jhelum Thrust is an active fault that accommodates east-west shortening in the region.
- The document discusses the regional geology, including the three main tectonic terrains of the Asian plate, Kohistan island arc, and Indian
The document summarizes information about the 2005 Mw 7.7 Kashmir-Hazara earthquake in northern Pakistan. Key points:
- The earthquake ruptured the active Jhelum Thrust fault, killing over 100,000 people. It was one of the most destructive earthquakes along the Himalayan arc.
- The earthquake provided new insights into the regional tectonic framework and origin of the Kashmir-Hazara Syntaxis. The Jhelum Thrust is an active fault that accommodates east-west shortening in the region.
- The stresses from the earthquake indicate another potentially large earthquake could occur further south along the Jhelum Fault, which extends from the earthquake area towards
The document provides an introduction to seismic design, including:
1) It discusses plate tectonics and how earthquakes occur at plate boundaries.
2) It describes different effects of earthquakes like ground shaking, liquefaction, landslides, and tsunamis.
3) It explains seismic design categories which depend on location, soil type, occupancy, and expected ground shaking. The design category determines the required design procedures.
TABLE OF CONTENT
>Introduction
>General Morphology of Subduction Zone
>Ocean Trenches
>Back Arc Basins
>Accretionary Prism
>Variation in Zones Characteristics
>Structure of Zones from Earthquakes
>Thermal Structure of Down-going Slab
>Gravity Anomalies
>Volcanic and Plutonic Activity
>Metamorphism at convergent boundaries
The 2015 Gorkha, Nepal earthquake caused widespread damage due to geotechnical factors. Soft soils in Kathmandu Valley amplified ground shaking levels, contributing to more severe damage. Local geology, such as ridge topography and basin edges, also influenced damage patterns through effects like soil amplification and energy focusing. Thousands of landslides were triggered, and liquefaction occurred sporadically along basin edges. While bridges suffered minor impacts, many roadways were blocked by landslides and rockfalls. The study concluded local site conditions strongly impacted damage levels.
The Role of Strike Slip Faulting in the History of the Hukawng Block and the ...MYO AUNG Myanmar
https://www.researchgate.net/publication/331115764_The_role_of_strike-slip_faulting_in_the_history_of_the_Hukawng_Block_and_the_Jade_Mines_Uplift_Myanmar
The role of strike-slip faulting in the history of the Hukawng Block and the Jade Mines Uplift, Myanmar
February 2019Proceedings of the Geologists Association
DOI: 10.1016/j.pgeola.2019.01.002
The Hukawng Basin is bounded on its east by splays of the still-active Sagaing Fault. Palinspastically restoring Myanmar's blocks to their positions before the widely-accepted c.400 km dextral strike-slip fault displacement, places the Hukawng Block alongside the Tengchong Block, suggesting they were formerly connected. Additionally the Cretaceous–Paleogene Medial-Myanmar Shear Zone then aligns with the NW-SE Jade Mines Belt. Jadeitite formed there under HP/LT conditions in a Mesozoic subduction zone. It was exhumed at the intersection of the dextral Medial-Myanmar Shear Zone with the subduction-zone at the continental margin of Sundaland. The later Sagaing Fault played no part in that exhumation.
Seismology is the study of earthquakes and seismic waves. It has four main branches: observational seismology which records earthquakes and catalogs them; engineering seismology which estimates seismic hazards; physical seismology which studies the interior of the Earth; and exploratory seismology which uses seismic methods for applications like oil exploration. The study of seismology helps us understand earthquakes, predict their effects, and design structures to withstand shaking. It provides insights by analyzing seismic waves recorded on seismograms at stations around the world.
This document is a seismic microzonation study for the master plans of Gilgit Nomal and Naltar conducted in December 2019. It was prepared by Syed Kazim Mehdi and produced by MM Pakistan (Pvt) Ltd for seismic hazard assessment and mitigation in the areas' long term development plans through 2040.
The document summarizes a seismic hazard study for a bus rapid transit project in Peshawar, Pakistan. It identifies seismically active features near Peshawar based on historical earthquake data. A probabilistic seismic hazard analysis was performed dividing the region into seven seismic zones based on tectonic characteristics. The analysis found a peak ground acceleration of 0.23g for a 475 year return period, consistent with the project falling in zone 2B of the Pakistani building code which ranges from 0.16g to 0.24g.
The document provides a summary of a seismic hazard study for the Peshawar Bus Rapid Transit Corridor Project. It analyzes the regional tectonic setting and identifies major active faults in the project area, including the Main Karakoram Thrust, Kohistan Faults, and Main Mantle Thrust. A probabilistic seismic hazard analysis is conducted considering seven seismic source zones. The analysis finds a peak ground acceleration of 0.23g for a 475-year return period, consistent with the project area being in Seismic Zone 2B according to the Building Code of Pakistan.
This document provides information about an earthquake that struck Pakistan on October 8, 2005 through a just-in-time lecture format. It begins with background on the Global Health Network Disaster and outlines objectives to provide scientific information about the earthquake and teach preparedness. Details provided include the earthquake's magnitude, location, impacts such as deaths and displaced people, and health needs like lack of sanitation and medical services. The document emphasizes preparing for future disasters through lessons learned and educating children now.
The document summarizes a study on seismic hazard evaluation for the Diamer Basha Dam site in Pakistan. A local seismic network was established in 2007 to monitor earthquake activity in the area and provide data for the study. Seismic hazard assessment was conducted using probabilistic and deterministic methods, establishing three seismic source zones with maximum magnitudes up to 7.8. Deterministic analysis found the Main Mantle Thrust yielded the highest ground accelerations. Probabilistic analysis assigned a peak ground acceleration of 0.33g with a 10% probability of exceedance in 50 years for dam design.
This document summarizes the characteristics of the 2005 Kashmir-Hazara earthquake in Pakistan and its connection to the Indus Kohistan Seismic Zone. Some key points:
- The M7.7 earthquake occurred on October 8, 2005 near Muzaffarabad and Balakot, killing over 100,000 people. Fault plane solutions showed thrust faulting was responsible.
- The earthquake reactivated the Balakot-Bagh reverse fault, with up to 7 meters of vertical separation observed along 70 km of the fault.
- The region lies within a tectonically active zone where the Indian plate is subducting beneath the Eurasian plate. Numerous active faults result from the north
The document summarizes a study on induced seismicity at the Tarbela Reservoir in Pakistan. Some key findings include:
- Seismic activity and energy release were found to be six times greater when the reservoir level was below 120m compared to above 120m.
- Energy release was also generally higher from November to May compared to June to October, relative to pre-impounding seismicity levels.
- For two major faults near the reservoir, the rate of energy release was three times greater when the reservoir level was below 120m.
This document summarizes key details about the 2008 Wenchuan earthquake in China:
1. The magnitude 8.3 earthquake struck the Sichuan province on May 12, 2008, causing over 69,000 deaths.
2. The earthquake occurred along the Longmenshan fault as the result of the convergence between the India and Eurasian tectonic plates.
3. The earthquake generated large surface deformations and increased stress levels at the ends of the ruptured fault, raising risks of future seismic activity.
The 2005 Kashmir-Hazara earthquake originated from a shallow depth of 16 km due to the subduction of the Indian plate beneath the Eurasian plate. It had a magnitude of 7.7 and ruptured the Jhelum Thrust fault, causing over 86,000 fatalities. The earthquake was located in the seismically active Kashmir-Hazara Syntaxis region, which accommodates shortening through structures like the Main Boundary Thrust and Jhelum Thrust. Aftershocks continued migrating northwest along the northern end of the Syntaxis, activating other deep crustal seismic zones in the region.
1) A 7.7 magnitude earthquake occurred in northern Pakistan in October 2005, caused by movement on the Jhelum Thrust fault located in the Kashmir-Hazara region.
2) The Kashmir-Hazara region has complex geology and seismotectonic activity due to the convergence of the Indian and Eurasian tectonic plates. Major faults like the Main Boundary Thrust and Jhelum Thrust are active.
3) The 2005 earthquake ruptured along the Jhelum Thrust fault, which was previously not well-mapped but is now confirmed to reach the surface, causing widespread damage and over 86,000 fatalities.
This document summarizes a study on the 2005 Kashmir Hazara earthquake and its implications for the Jhelum Thrust Zone in northern Pakistan. The M7.7 earthquake caused over 85,000 deaths and widespread damage. It reactivated the Jhelum Thrust Zone, along which increased seismic activity has been observed since, including a 2005 M5.3 earthquake. The study suggests the Jhelum Thrust Zone is actively building strain and a major earthquake could impact the Mirpur area in the future, calling for improved building codes and infrastructure monitoring along the fault.
This document summarizes characteristics of reservoir induced seismicity observed at the Tarbela and Mangla Dams in Pakistan. It finds that both dams display similar seismic characteristics as other reservoirs worldwide, including an inverse correlation between seismic activity and reservoir level. Analysis shows the reservoirs experience increased seismicity during drawdown periods. The document also provides background on the geodynamic setting of the region, noting it is characterized by the ongoing collision of the Eurasian and Indian tectonic plates, forming the Himalayan mountain range.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
New techniques for characterising damage in rock slopes.pdf
Simly vol i (ff)
1. WATER AND POWER DEVELOPMENT AUTHROITY
SIMLY DAM PROJECT
SEISMOTECTONICS & SEISMIC HAZARD ANALYSIS
Volume-I
SEPTEMBER 2015
SUBMITTED BY
DIRECTORATE OF SEISMIC STUDIES
OFFICE OF THE
GENERAL MANAGER & PROJECT DIRECTOR
TARBELA DAM PROJECT
2. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
1
TABLE OF CONTENTS
Section Description Page No.
1.0 Introduction 1
2.0 Geology of the Area 2
2.1 Stratigraphy 2
2.2 Structural Geology 2
2.3 Joints and Fractures 3
3.0 Regional Tectonic Setting 3
4.0 Local Tectonic Setting 4
4.1 Jhelum Thrust Fault 6
4.2 Darband Fault 6
4.3 Margalla Fault (MF) 7
4.4 Main Boundary Thrust(MBT) 8
4.5 Panjal Thrust Fault 8
4.6 Nathiagali Thrust (NT) 8
4.7 Thandiani Thrust (TT) 8
4.8 Indus Kohistan Seismic Zone (IKSZ) 9
4.9 Hazara Thrust Fault 9
4.10 Dil Jabba Fault 9
5.0 Seismotectonics 10
6.0 Methodology Adopted For The Studies 11
7.0 Previous Geological Studies 12
3. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
II
8.0 Previous Seismological Studies 15
8.1 Pamir-Karakorum Province 15
8.2 Hazara Region Province 15
8.3 Himalayas Province 16
8.4 Salt Range Province 16
8.5 Indus Basin Province 17
9.0 Earthquake Cataologue 17
9.1 Pre-Instrumental Seismicity 17
9.2 Catalogue of Felt Earthquakes 18
9.3 Instrumental Seismicity 19
10.0 Seismotectonic & Seismic Hazard Analysis (SSHA) 21
10.1 Deterministic Seismic Hazard Analysis (DSHA) 23
10.2 Probabilistic Seismic Hazard Analysis (PSHA) 31
11.0 Safety Evaluation Earthquake (SSE) 34
12.0 Combining Seismic Hazard Analyses 34
12.1 Selection of Peak Ground Acceleration (PGA) 34
13.0 Estimation Of Acceleration Response Spectra 35
13.1 Response Spectra Based on Statistical Analysis of Strong
Motion Data 36
13.2 Scaled Accelerograms 36
14.0 Safety Monitoring 37
15.0 Conclusions 38
Refrences 39
4. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
III
Details of Figures
Figure ______Page
Figure-01: Movement of Indo-Pak plate & Eurasian plate……………………..42
Figure-02: Seismotectonic Map of Pakistan. ........……………………………….43
Figure-03: Seismic Zoning Map of Pakistan……………...……………………...44
Figure-04: Regional Tectonic Map showing major Tectonic Features of
Northern Pakistan……………………………………………………..45
Figure-05: Local Seismotectonic Setup…………………………….……………..46
Figure-06: Geology of Bagh-Balakot Fault & Location/FMS of
Main KH Earthquake…………………………………..……………..47
Figure-07: Fault Plane Solutions of Earthquakes around Simly Dam Project...48
Figure-08: Location of Seismic Events around Simly Dam with EW depth section
Seismic Events within 200 km. radial distance .……….…………….49
Figure-09: Location of Seismic Events around Simly Dam with NS depth section
Seismic Events within 200 km. radial distance………...…………….50
Figure-10: Location of Seismic Events with Mw ≥ 3.0…………………………..51
Figure-11: Seismic Zones around Simly Dam Project with Seismic Events
Mw ≥ 3.0………………………………………………………………..52
5. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
IV
Figure-12: Earthquake History of Simly Dam Project…………………………..53
Figure-13: Cumulative No. of Earthquakes around Simly Dam Project……….53
Figure-14: ‘b’ Value of Earthquakes around Simly Dam Project………………54
Figure-15: Attenuation Relationship for Simly Dam Project……………………54
Figure-16: Seismic Hazard Curve for Simly Dam Project……………………….55
Figure-17: Acceleration Time History and Response Spectra of Artificial
Earthquake for MCE Horizontal-1 Component……………………...56
Figure-18: Acceleration Time History and Response Spectra of Artificial
Earthquake for MCE Horizontal-2 Component……………………...57
Figure-19: Acceleration Time History and Response Spectra of Artificial
Earthquake for MCE Vertical Component…………………………..58
Appendix (VOLUME-II)
Appendix-I…………………………………………………………………………….....59
Appendix-II………………………………………………………………………………62
Appendix-III……………………………………………………………………………..66
6. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
1
SEISMOTECTONICS & SEISMIC HAZARD ANALYSIS
OF
SIMLY DAM PROJECT
1.0 INTRODUCTION
Simly Dam is situated only 30 K.ms. East of Islamabad and a source of providing up to 105m3
,
drinking water per day for the residents of the Capital. It is administered by the Capital
Development Authority (CDA) of Pakistan. The situation harnesses flow of the Soan River at
Simly creating a reservoir with live storage of 20,000 acre feet. The Soan River at Simly has a
catchment area of 59 sq. miles.
Salient features of Simly Dam are as under:
Type of Dam Embankment.
Height of Dam 80 meters.
Rockfill 1,808000 cu. yds.
Impervious fill 640,000 cu. yds.
Length of Dam 313 meters.
Length of Upstream Coffer Dam 322 feet.
Max. height of Upstream Coffer Dam 90 feet.
Random Rockfill 32,500 cu. yds.
Impervious fill 84,900 cu. yds.
Length of Downstream Coffer Dam 211 feet.
Max. height of Downstream Coffer Dam 35 feet.
Random Rockfill 16,700 cu. yds.
Overflow weir of Spillway 110 feet at crest.
Discharge capacity of Spillway 45,000 cusecs.
Concrete Volume of Spillway 39,600 cu. yds.
Tunnel Diameter of Water Intake Structure 6 feet.
Length of Water Intake Structure 570 feet.
Discharge Capacity of Water Intake Structure 44.5 cusecs.
Concrete Volume of Water Intake Structure 1,790 cu. yds.
Size of Drainage Gallery with Drainage Wells 5 x 7.5 feet.
Length of Drainage Gallery with Drainage Wells 432 feet.
Length of Reservoir 7 miles.
Area of Reservoir 421 acres.
Gross Storage of Reservoir 35,463,000 m3
Live Storage of Reservoir 24,669,000 m3
Dead Storage of Reservoir 10,794,000 m3
7. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
2
The Project is situated in a highly earthquake prone area. Keeping in view the importance of its
existence regarding the source of fresh water supply and its geographical location in a Zone of
Earthquake occurrence, it was need of the time to carry out a fresh Seismotectonic and Seismic
Hazard Analysis (SSHA) of the Simly Dam Project especially in the after math of Kashmir-
Hazara Earthquake of October 08, 2005 and thousands of aftershocks.
The present study was taken up by the Directorate of Seismic Studies, Tarbela Dam Project as
was suggested in the periodic inspection of Simly Dam and later on this office was assigned the
task by CDA.
2.0 GEOLOGY OF THE AREA
2.1 Stratigraphy
The dam site is underlain by sediments of Chingi group of formation of Siwalik (Middle
Miocene) age. The rocks of this formation consist of alternating beds of sandstone, siltstone .and
claystone. The layers of resistant sandstone form sharp ridges and are separated by depressions
formed due to erosion of soft rocks which also include friable sandstone. Upstream and
downstream of the dam site, the river flows along the strike of the formations however, at the
gorge, the flow of the river veer sharply and a canyon at right angle to the strike of the
formations is formed,
2.2 Structural Geology
These rocks have been folded into sharp anticlines and synclines trending northeast to southwest.
Simly plain and the reservoir occupy the axial region of one of those asymmetrical anticlines.
The rocks exposed at the abutments form the eastern limb of the major anticline and consist of
sandstone inter bedded with siltstone and claystone.
The rocks have open bedding joints and cross joints in particular on the left abutment due to
stress relief on the valley side, creep along the clay stone beds and flexural folding. This type of
folding although is a common feature where competent and incompetent beds alternate but this
secondary folding in the left abutment area has caused opening up of the bedding planes strike
wise and cross joints. The strike of the rock formations as a whole is approximately N400E, the
dips averaging 80° to 85° to the southeast along the eastern limb of the anticline and from 50° to
70° to the northwest along the western Limb.
8. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
3
2.3 Joints and Fractures
The sandstones are cut by several joints systems, one parallel to the stratification and two sets
striking N40~ and dipping 45° to the northeast., the other 45° to 75° to the southwest. In addition
to these there are also some random joints. The stratification joints are well marked and cause
open fractures in and near the weaker formations such as friable sandstone, siltstone and
claystone. These joints are very, inconspicuous in main body of sandstone. The cross joints have
been widened by weathering and solution near the surface.
At the dam site most, of the joints and fractures are closely spaced, opened, partly coated with
calcite and occasionally silken sided. Most of the clay stones show signs of shearing and the
partings are generally coated with chlorite. This shearing appears to be very irregular in strike
and dip. The sandstone/claystone, contact is sheared and at places up to 2 ft. claystone at the
contact is crushed.
3.0 REGIONAL TECTONIC SETTING
The seismically active nature of Pakistan and its adjacent region is well known because of the
occurrence of some of the biggest earthquakes of the world. These include the 1819 Kutch
earthquake, the 1931 Much, the 1935 Quetta earthquakes in Baluchistan, and the 1945 Makran
earthquake. Some events that caused loss of life and destruction in Northern Pakistan during the
recent past are the 1974 Pattan earthquake of Mb 6.0, Rawalpindi earthquake of 1977 having mb
5.2, two Bunji earthquakes of mb 5.3 and 6.0 that occurred in 2002, two Batagram earthquakes
of mb 5.3 and 5.5 that took place in 2004, and the October 8, 2005 Kashmir-Hazara earthquake
with Mw 7.6 (Mehdi 2008 & 2010).
Earthquakes in the Northern Pakistan are the result of the on-going northward subduction of the
Indo-Pak plate underneath the Eurasian plate at a rate of about 40 mm/year (Figure-1). As a
result of this impact, the highest mountain ranges of the world, the Himalaya, Karakoram, Pamir,
and Hindukush, have formed. In this area of dominant compression, transpressional tectonic
features are also present (Monalisa et al. 2004, 2007). The north- and northeast directed
compression has produced major thrust faults such as the Shyok Suture (or main Karakoram
Thrust, MKT), Indus Suture (or main mantle thrust, MMT), and the MBT shown in Figure-2, as
well as many active faults of variable length, e.g., the Himalayan frontal thrust, etc.
Transpressional features in the area include strike slip faults named as Jhelum, Thakot, and
Raikot Faults. In addition to these, existence of shallow to deep crustal faults, like the NW
trending Indus Kohistan Seismic Zone (IKSZ) and Jhelum Thrust Fault has also been proposed.
9. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
4
The Indo-Pak plate, relative to the Eurasian plate is still moving northwards at a rate of about 3.7
cm/yr. near 730
longitude east (Molnar & Topponnier, 1975). The major portion of this
convergence was taken up by deformation along the northern collision boundary involving
folding and thrusting of the upper crustal layers (Seeber & Armbruster, 1979) in the shape of
Main Karakoram Thrust (MKT), Main Mantle Thrust (MMT), Main Boundary Thrust (MBT)
and Salt Range Thrust (SRT), as shown in Figures 3 & 4.
Pakistan lies on the western edge of the Indian plate, bordered to the west and
north by the Eurasian plate and to the southwest by the Arabian plate. All
these three plates are mutually converging, although the mechanisms differ
from northern part to south-western zone. Figure-1 shows arrows with marks
1, 2, and 3. Mark-1 arrow indicates the Himalayas collision zone in the north.
Simly Dam Project site is located in a part of the western Himalayas, which marks a major bend
in the Himalayan trend termed as the Western Syntaxis (Wadia, 1957). East of this Syntaxis, the
Himalayas have a NW-SE trend compared to the part of the Himalayas west of the Syntaxis
which have a WSW-ENE trend (Figures-2, 3 & 4). The western Syntaxis comprises two
syntaxial bends. One in the north, involving Higher Himalayas and the Kohistan Block, is termed
the Nanga Parbat Syntaxis, while southern bend involving the Lesser and the Sub-Himalayas is
termed Hazara-Kashmir Syntaxis (Calkins et al., 1975). It is the Hazara-Kashmir Syntaxis, which
marks the junction between the Kashmir Himalayas in east and the Hazara-Potwar Himalayas in
the west and most significant to tectonic setting of the Project area (Mehdi 2010).
The presence of some of the active faults like Main Central Thrust (MCT), Main Mantle Thrust
(MMT), Punjal Thrust (PT), Jhelum Thrust (JT), Jhelum Fault (JF) and Main Boundary Thrust
(MBT) etc make the Simly Dam Project area very active tectonic regime (Figure-1). In this area
of dominantly collisional tectonics a large number of focal mechanism solutions indicate strike-
slip faulting and/or thrust faulting. A kinematic change from compression to transpression is
thought to be taking place. Both historical/non instrumental (Oldham, 1893; Ambraseys et al,
1975 and Quittmeyer et al., 1979) and instrumental data exist in the area (Figures 3 & 4).
4.0 LOCAL TECTONIC SETTING
On local scale Islamabad is located in the Himalayan fold-and-thrust belt, which covers the area
between the MMT and SRT. The Panjal-Khairabad fault divides the belt into a northern
hinterland zone and the southern foreland zone. The former is characterized by intensely
deformed (tightly folded and imbricated) Precambrian to Early Mesozoic igneous and
metamorphic rocks collectively called the Himalayan crystalline nappe-and-thrust belt by Kazmi
and Jan, 1977. These crystalline rocks towards the south are thrusted over the rocks of the
foreland zone. This foreland zone comprises of many thrust sheets (decollement zones) with
southward translation of up to 100 km. In the east, separating the fold belt from the central
10. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
5
Himalayas fold belt of India is the N-S trending complex tectonic zone called the Hazara-
Kashmir Syntaxis (HKS). Precambrian to Neogene rocks is present in the syntaxial zone
although the Oligocene-Miocene Murree formation predominates (Figure-5).
The Simly-Islamabad area lies in a tectonically active zone, where faulting, folding, and
earthquakes have been frequent in the recent geologic past. In A.D. 25, the Buddhist monasteries
at Taxila, 25 km west-northwest of Islamabad, were destroyed by an earthquake estimated at
Modified Mercalli intensity IX. More recently, Richter magnitude 5.8 earthquakes on February
14, 1977, centered 15 km northeast of Islamabad caused damage indicating Modified Mercalli
intensity VII near the epicentre. According to the studies each year there is a 50 percent chance
of a Richter magnitude 4 earthquake, an 8.33 percent chance of magnitude 5, a 1.67 percent
chance of magnitude 6, a 0.26 percent chance of magnitude 7, and a 0.11percent chance of
magnitude 7.5 (recurrence intervals of 2, 12, 66, 380, and 912 years, respectively) (Mehdi 2008
& 2010). The dominant factor controlling the geology of the Islamabad area is the convergence
of the Pakistan India and Eurasian tectonic plates. The city of Islamabad is situated in the Potwar
plateau (Figure-5), which is an area between Main Boundary Thrust (MBT) and Salt Range
Thrust (SRT). In the north Margalla and Hazara ranges while in the west mountainous region of
Kalachitta ranges cover the area. The southward portion encompasses the Salt range.
Two seismically active faults i.e. MBT in the north and Riwat Thrust in the south of Islamabad
(Figure-5) are passing nearby, indicating that the study area is located within the seismically
active environment. The Riwat thrust trending in the NE-SW direction lies about 20 km south of
Islamabad. Jadoon et. al. 1995 believes that cessation of movement along the Riwat Thrust
stopped at about 2.7 Ma. Soan (Dhurnal) backthrust is another distinctive feature of the eastern
Northern Potwar Deformed Zone. It occurs on the northern limb of the Soan Syncline
immediately south of Islamabad. The MBT itself is represented by many high angle thrust along
which Eocene and older rocks have been thrusted over the molasses of the Potwar plateau. The
Soan (Dhurnal) backthrust is a passive back thrust and the area bounded by it and the Khair-i-
Murat fault is a triangle zone of complex Geology. Pivnik and Sercombe (1993 & 1998)
recognize the presence of strike-slip faults at the surface and even in the basement in this area.
They relate the structures (high angle strike-slip faults and associated flower structures) to
transpressional deformation.
The collision between the plates that began about 20 million years ago produced complex
structure and stratigraphy in the Islamabad Rawalpindi area that have been studied by many
Pakistani and foreign geologists. The faults which have been taken into consideration in the
present studies and which may have potential effect on the safety and integrity of Simly Dam are
described as under and sketched in the Figure 5.
11. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
6
4.1 Jhelum Thrust Fault
It is an important strike-slip fault trending north-south, which tracks the western periphery of
axial zone of Hazara-Kashmir syntaxial bend. The fault was reported by the original researchers
to extend along the Jhelum River and further south-wards to the Chaj Doab. Between
Muzaffarabad and Kohala, this fault apparently dislocates the MBT and a left-lateral offset of
about 30 km is indicted on the western limb of the syntaxes. In this region of Murree,
Abbottabad and Hazara the geological formations are extremely deformed as well as displaced
several km south- wards.
Jhelum fault apparently dislocates from the Main Boundary Thrust and terminates the eastward
continuation of some of the geological structures of North West Himalayan Fold and Thrust
Belts. These tectonic relationships indicate Jhelum fault as the youngest major tectonic feature in
the syntaxial zone.
Jhelum fault is located at a distance of about 50 km east of Islamabad. This fault was reported by
original researchers to extend along Jhelum River from north of Muzaffarabad to near Jhelum
and further southward to Chaj Doab area. During recent studies it was investigated whether this
fault extends southward up to Jhelum or not. OGDCL has mapped a fault parallel to Jhelum
River up to Palala Mullah, beyond which it takes a southwest bend and extends parallel to other
faults (Dil Jabba, Lehri) of the area as a thrust fault. No evidence of southern extension of the
Jhelum fault beyond this point is observed.
Quaternary deposits have been observed deformed along the Jhelum fault near localities of
Barin, Jabba, and Palot. In addition, numerous shear zones in the Siwaliks rocks and associated
deformations within sub-recent deposits are observed along this fault near Panjgran. It is the
youngest and active major tectonic feature in the syntaxial zone. Based on the seismicity, the
fault is quite an active one (Mahdi, 2005).
4.2 Darband Fault
Calkins et al. (1975) suggest the presence of a major strike slip fault traversing along the Indus
river channel under Tarbela Dam near the right bank of Indus. This fault is located in a narrow
belt along the Indus River, where the geologic structures appear to form a Northward projecting
loop called Indus re-entrant. North of Tarbela dam, Darband fault follows the gorge of Indus
River. South of Tarbela Dam, the Darband fault continues down the Indus river under the river
alluvium and emerges as a wide shear zone in Bara ridge on the west bank about 3 km.
downstream of the dam. From this point the fault turns abruptly northwest, where it can be traced
to the edge of the alluvial cover of Peshawar basin on the other side of the ridge. Some
researchers have suggested that the Darband fault branches downstream of the dam and the main
fault runs in Southwest direction between Pihur and Topi.
12. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
7
Darband fault is one of the steeply dipping parallel faults aligned along the Indus River. These
faults are often referred to as “Indus Fault System” and are located in the narrow belt along the
Indus River where the geologic structures appear to form a northward-projecting loop, called
Indus Re-entrant.
Darband fault is the main fault of this system. It is a northeast trending strike-slip fault, which
traverses along the right bank of Indus River near the Tarbela Dam. It has developed an
overhanging escarpment of Indus River gravels, which is 140~210m high and was clearly
exposed during the excavation for Tarbela Dam foundations. The excavations revealed that it is
a reverse fault dipping at 65 degrees northwest. The geological contacts between Salkhala and
Tanawal formations on the right side and Kingriali Formation on the left side of the river
channel near dam, further confirm the existence of Darband fault.
North of Tarbela dam, Darband fault follows the Indus River gorge between villages Nawan
Garan and Khar Kot, where it splits into a pair of north dipping thrust faults named as Dangror
and Kharkot faults. Outcrops of these faults are clearly visible in the field. Near the village of
Sunbai, it is inferred that these two thrust faults again converge to a single north-south trending
fault and extend up to Darband Village.
South of Tarbela, the Darband fault continues down the Indus River under the river alluvium and
emerges as a wide shear zone in Bara ridge on the left bank about 3 km downstream of the dam.
From this point the fault turns abruptly northwest where it can be traced up to the edge of the
alluvial cover of Peshawar basin on the other side of the ridge.
Total length of the Darband fault is about 50 km. However, the strike slip portion of this fault
along the Indus is only about 30 km.
Quaternary deposits within the vicinity of Darband fault have been found tilted between 20o
south and 40o
north and are at places cut by northeast trending faults having minor
displacements. Pre-Tarbela Dam aerial photographs also indicated left lateral offsets in stream
flows. Based on the deformations observed with the Quaternary deposits and recorded
seismicity, the Darband fault is considered seismically active.
4.3 Margalla Fault (MF)
Margalla Fault (MF) is an important fault, which runs along NE-SW direction and joins the main
boundary thrust (MBT) in the Hazara-Kashmir syntaxial zone. It passes north of Islamabad on
the southern piedmont slopes of the Margalla Hills. As a result of this fault, the Datta formation
and the Samanasuk limestone are thrusted over the Lockhart limestone. There is no record or
indication of any recent movement along the Margalla fault.
13. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
8
4.4 Main Boundary Thrust (MBT)
The Main Boundary Thrust is a distinct and important tectonic feature along the entire
Himalayan Belt. The MBT loops around the Hazara syntaxial zone. It represents the major zone
of recent deformation and the largest earthquakes. The MBT stretches from the Afghan border,
and can be traced nearly continuously to the Assam through Eastern India. It is the single most
potent earthquake source in the Himalayas. Islamabad- Rawalpindi area is located at a close
distance south of the western limb of the MBT.
4.5 Punjal Thrust Fault
The Punjal Thrust structure is sited parallel to MBT on the eastern limb of the Syntaxes. The
Punjal Thrust probably separates from MBT about 6 km south of Balakot and continues beneath
Kaghan Valley alluvium up to Ghari Habib Ullah. Punjal Thrust is an active fault and represents
south-eastern tectonics of the area. Punjal Fault appears as reverse fault with strike-slip
component, in the south of Abbottabad (Calkins et al. 1975).
4.6 Nathiagali Thrust (NT)
On a regional scale, the Himalayas have been divided into internal (or hinterland) and external
(or foreland) zones (Coward et al., 1988). MMT marks the northern limit of the internal zone
which comprises of crystalline rocks of Naran, Upper Kashmir, Upper Hazara, Besham and
Swat. The external zone, which is a type of foreland thrust-fold belt, is comprised of successions
of stratified rocks of Hill Ranges (e.g., Koha, Kalachitta, and Margalla), the Salt Ranges-Trans-
Indus Ranges and Potwar-Kohat plateau. The tectonic boundary between the northern internal
and southern external zones is demarcated by The Nathiagalli-Khairabad Thrust. Nathiagali
Thrust (NT) branches off towards the western side from the Jhelum Fault near the village of Rara
which is situated some 5 kilometres south of Muzaffarabad along Muzaffarabad-Kohala road
(Greco and Spencer, 1993). From Rara it almost runs parallel to the Jhelum Fault in North-South
direction separating Hazara Formation from the Rara Formation. Rara-Kohala segment of
Nathiagali Thrust exhibits strikeslip behaviour. Near Kohala, Nathiagali Thrust takes turn along
the Bakot Nala and runs towards southwest direction where it thrusts the Precambrian slates over
the Mesozoic formations and up to Tertiary Kuldana Formation (Burg et al., 2005).
4.7 Thandiani Thrust (TT)
On the western side of HKS, the number of thrust faults like Thandiani Thrust (TT) and
Nathiagali Thrust (NT) are situated and these dip to the north and northwest (Baig & Lawrence,
1987). Structurally they overlie each other so that the Nathiagali Thrust lies below the Thandiani
Thrust.
14. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
9
4.8 Indus Kohistan Seismic Zone (IKSZ)
A wedge-shaped northwest trending structure between MMT and HKS is known as IKSZ and
Armbruster et al., 1978; Seeber and Armbruster, 1979. Ni et al. (1991) confirmed the presence of
almost 100 km long feature between the HKS and MMT. This 50 km wide zone has nearly
horizontal upper surface and a northeast dipping lower surface of seismicity along IKSZ
(Monalisa et al., 2008 & Mehdi 2010).
The IKSZ is seismically the most active structure capable of generating large earthquakes in the
region. It is predominantly a thrust fault with a northwest strike and northeast dipping plane
parallel to the general trend of the MBT to the northeast of Muzaffarabad (Monalisa et al., 2008).
However, IKSZ with MBT is not comparable because both have different tectonic history, as
based on surface geology (Gahalaut, 2006). The most destructive earthquake prior to Kashmir
earthquake 2005 associated with IKSZ was the 28 December, 1974 Pattan earthquake with
magnitude 6.0. The IKSZ represent the reactivation of decollement surface and have short term
stress field which may cause the broad zone of scattered seismicity and is responsible for the
Kashmir earthquake 2005 (Monalisa et al., 2008, Figure-6).
4.9 Hazara Thrust Fault
Islamabad -Simly Dam are on the south margin and leading edge of the Hazara fault. It shapes
like an arc of thrusted and folded rocks about 25 km wide and 150 km long that is convex to the
south and extends west-south-westward away from the Himalayan syntaxes. In the project area,
the thrust fault is slightly oblique to the front of the Margalla Hills; hence, it is projected west-
south-westward beneath the cover of the piedmont fold belt.
4.10 Dil Jabba Fault
Dil Jabba fault is northeast trending thrust which originates north of Khewra in the eastern Salt
Range and apparently terminates near the right bank of Jhelum River. It dips towards northwest
as other major thrusts of Salt Range and Hazara regions. The approximate length of this thrust is
86 km and it passes at a nearest distance of about 75 km southeast of Islamabad.
This fault is located on the western side of the northeast trending Jogi Tilla ridge. Near Bakrala
ridge area towards east, the main thrust bifurcates into two sub-parallel thrusts having same
northeast trends up to near Domeli. Both these thrusts again converge to one main thrust beyond
Domeli. North of Chak Miana its extension is not known as it is concealed under the alluvium.
Quaternary deformations associated with the Dil Jabba Thrust have been observed in Upper
Siwalik Soan Formation of Upper Pliocene to Lower Pleistocene age and in sub-recent fluviatile
and lacustrine sediments, which un-conformably overlie the Upper Siwalik sequence at many
15. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
10
places along this fault. Tilting and shearing in alluvial deposits associated with Dil Jabba thrust
has been observed at an exposure near Taraki on Grand Trunk road.
A description of the above described local tectonic features suggests that whole northern part of
Pakistan lies in the collisional zone of the northern part of Indian plate with associated faults that
show evidences of fault movement during Quaternary period and should therefore be considered
seismically active.
5.0 SEISMOTECTONICS
The particular aspect of geology which sheds most light on the source of earthquakes is
tectonics, which concerns the structure and deformations of the crust and the processes which
accompany it; the relevant aspect of tectonics is now often referred to as
Seismotectonic. Tectonic features can produce specific earthquakes of maximum magnitude
potential. Moreover, their associated seismicity also helps us about achieving the goal of
determination of maximum magnitude potential.
Earthquakes are generated by tectonic process in the upper part of the earth called lithosphere
that is divided into several rigid parts called as “Plates”. Due to movement of these plates, stress
build up takes place and results in the deformation of the crustal mass. This energy accumulation
gives birth to seismic events. The contact zones between adjacent plates are, therefore,
considered as most vulnerable parts from the seismic hazard point of view.
Islamabad-Simly is located near the contact zone between the Indian plate and the Eurasian
plate. This contact represented by the Himalayas has always been generating moderate to large
earthquakes including Kangra (1905), Bihar-Nepal (1934) and Assam (1897) earthquakes that
have left their landmarks in the history.
The information about earthquakes in this region is available in two forms i.e. historically
recorded and instrumentally recorded earthquakes. The instrumentally recorded earthquake data
is available only since 1904. Before this, the source of earthquake information is through the
historical records and published literature. The Seismotectonic model is one of pivotal elements
concerning seismic hazard assessment. In this study, Seismotectonic model for Simly Dam has
been developed.
It is worth mentioning that the Seismotectonic modelling is actually the identification of
potential seismic sources in the study area as an evaluation of the tectonic history of the region
considering available geological data and information or an evaluation of historical as well as
recent instrumental seismic data in relation to the study area, emphasizing that these data are the
key empirical basis for conducting seismic hazard analyses.
16. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
11
Available and relevant geological information are examined in order to locate and characterize
the active and potentially active geological structures - faults which may represent a potential
seismic source which could influence the site. Maximum earthquake magnitude potentials are
evaluated using a combination of physical methods, historical seismicity and empirical evidence
from geologically similar regions.
A seismotectonic study evaluates the geologic and seismologic history for the Project site. It
defines the earthquake source or sources, determines the maximum earthquake potential for each
source, develops magnitude-recurrence relationships, and provides information for use in the
seismic attenuation studies. A seismotectonic study includes the identification and
characterization of faults and other geologic structures that may be the sources of the earthquakes
that could affect the site.
This effort typically starts with literature searches in the fields of tectonics, seismology, and
geology, and may contain analyses of remote sensing imagery, geophysical data, and field
mapping and exploration programs to verify and further evaluate documented or suspected
tectonically active structures.
Main objective of the present Seismotectonic and Seismic Hazard Analysis (SSHA) study was,
therefore, to compute proper ground motion parameters required as input for a seismically safe
of Project structures. In this connection, Maximum Credible Earthquake (MCE), Operating Basis
Earthquake (OBE) and the resulting Peak Ground Acceleration (PGA) that can be experienced at
the Simly Dam Project site with different levels of probability were evolved.
6.0 METHODOLOGY ADOPTED FOR THE STUDIES
A detailed Seismotectonic & Seismic Hazard Analysis (SSHA) was carried out mainly keeping
in view the Kashmir-Hazara earthquake of October 08, 2005. For that purpose, all the available
modern techniques were applied to work out ground motions due to Maximum Credible
Earthquake (MCE), and the Operating Basis earthquake (OBE). Such exercise included mainly
the studies as under:
i. Study all the available Geological, Seismological and Seismotectonic Reports.
ii. Compilation of dataset based on Local as well as International sources including a
level of damage from Historic Earthquakes.
iii. Compilation of dataset of earthquakes felt in and around the Project area along with
their Intensity on Modified Mercalli Scale (MMS).
iv. Compilation of dataset of instrumentally recorded earthquakes and documented by
National Earthquake Information Centre (NEIC) of United States Geological
17. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
12
Survey (USGS), International Seismological Centre (ISC) of United Kingdom (UK)
and Water And Power Development Authority (WAPDA) of Pakistan.
v. Analyzing recent earthquakes or data from micro-earthquake monitoring to gain
information on current stress orientations.
vi. Evaluation of datasets with respect to reliability and completeness. Analyzing
recent earthquakes or data from micro-earthquake monitoring to gain information
on current stress orientations.
vii. Study the available Top sheets and Geological Maps of the Project site. Find out the
capable faults that are affecting the Project site.
viii. Establishing relationships between identified faults and other seismotectonic
features and the historical seismicity by (1) integrating the data for identified faults
and other structures with the seismicity data to develop event/source correlations;
and (2) developing and evaluating conceptual models to explain significant
earthquake events that do not correlate with identified faults or other seismic
sources or geologic structures.
ix. Convert different magnitudes to moment magnitudes Mw using published
conversion relationships.
x. Generate frequency-distribution Graphs for earthquake sources in the Project area.
Establishing earthquake magnitude and distance pairs that would be expected to
produce the largest ground motions at the site.
xi. Using established standard methods and taking into account the potential seismic
sources viz. faults in the area, and using relevant ground-motion attenuation
relationships, assessment was made for ground motions and return periods.
xii. Developing magnitude-recurrence relationships.
xiii. Evaluation of seismic hazard parameters of the Simly Dam Project.
7.0 PREVIOUS GEOLOGICAL STUDIES
The earliest work on geology of this region dates back to the 2nd half of nineteenth century and
continued into the first half of previous century. This work is concentrated on the age
determination, stratigraphic correlation and structural and tectonic work. Examples of prominent
work in this area include Verchére (1866 and 1867), Wynne (1873), Lyddekar (1883),
Middlemiss (1896), Wadia (1928, 1931, and 1934).
18. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
13
o Wadia (1931) worked in detail on the Tectonics, Orogeny and stratigraphy of the Hazara-
Kashmir Syntaxis. He referred to it as “Syntaxis of the Northwest Himalaya” and
presented the earliest model for its formation. He inferred an original horst or a triangular
promontory of Gondwanaland (which he termed ‘The Foreland’) to be the main reason of
formation of the Syntaxis. According to him, the foreland is tectonically overlain by ‘The
Autochthonous Fold Belt’ which itself is lying below the ‘The Nappe Zone’. Wadia
(1931) divided the area into eight major mappable stratigraphic units (Figure-4).
o Calkins et al. (1975) mapped the area in detail and explained the stratigraphy and
structure of a sequence of rocks that range in age from Precambrian to Miocene. They
reported that the structural pattern of western limb of Hazara-Kashmir Syntaxis
developed in two phases of deformation. In the first phase, the tectonic transport was
towards south having strong east and southeast wards pressure while the second phase
demonstrates the west and southwest wards countermovement of rocks in the compressed
axial zone in response to the continued south and southwest wards movement of rocks on
the longer eastern limb. The major structural terminologies used in this thesis are taken
from Calkins et al. (1975) e.g. Muzaffarabad Anticline Syntaxis by integrating the rock
deformation and regional scale tectonics. They reported two sets of superimposed major
folds with related minor structures. Hence they presented a tectonic model for the
formation of Hazara-Kashmir Syntaxis that the Syntaxis is formed as a result of early
nappe formation by southwest ward thrusting of metamorphosed Himalayan rocks,
proceeded by development of large shear zone structure and lastly by the over thrusting
of rock units from northwest to southeast.
o Greco (1989) and Greco and Spencer (1993) discussed the stratigraphic, tectonic and
metamorphic features of the area. They divided the area into four main tectonic elements
(i.e. Sub Himalaya, Lesser Himalaya, Higher Himalaya and Kohistan sequence) and
correlated it with the Indian Kashmir Himalayas to the east. A tectonic model is proposed
based on detailed superficial structures including small scale structures (stretching
lineation, schistosity and crenulation cleavage), rock distribution and petrographic
studies. Geometrical superposition of deformational phases detected by small and large
scale structures and by pressure-temperature history of the collected samples is also in
accordance with this model. Greco (1989) gave the name ‘Rara Formation’ to a NS
oriented, fault bounded package of rocks lying between Murree Formation in the east and
Hazara Formation in the west.
o Bossart and Ottiger (1990) carried out pale magnetic and structural analyses of three
sections of Murree Formation along the core of the Hazara-Kashmir Syntaxis. These
sections are located in Jhelum, Velum and Kaghan valleys. Thus he reported 45° of
clockwise rotation of the axial zone of Hazara-Kashmir Syntaxis relative to the Indian
19. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
14
craton. Treloar et al. (1992) worked on the large scale tectonic geometries of Northwest
Himalaya. Taking the dominant transport direction throughout the Himalayan history as
towards S or SSE, He came up with a model that the Hazara-Kashmir Syntaxis has been
formed by the mechanical impediment by the interference and thus pinning of two
converging Pakistani and Kashmir thrust sheets. This pinning resulted in the rotation of
these sheets forming the present geometry of Hazara-Kashmir Syntaxis.
o Arab and Shah (1996) of Geological Survey of Pakistan published a detailed geological
map of Azad Jammu and Kashmir. Their map portrays good details and explanatory notes
on the stratigraphy, structure and economic geology of the area.
o Khan et al. (2003) mainly contributed on the structure, tectonics and stratigraphy of the
area. Based on residual gravity data in the area, they studied shallow geological structure
in the core of Hazara Kashmir Syntaxis. Avouac et al. (2006) determined displacement
along Muzaffarabad Thrust based on remote sensing analyses using sub-pixel correlation
of ASTER images. According to them, average displacement is around 4m with
maximum value of 7 m northeast of Muzaffarabad.
o Gahalaut (2006) classified the October 08, 2005 Kashmir earthquake as either entirely
occurring in the up dip part of Indus Kohistan Seismic Zone (IKSZ) or involving some
part of detachment under Kashmir Himalayas but definitely not occurring in the Kashmir
gap. Rather, he feared that this earthquake may have increased the stresses in Kashmir
Himalayas.
o Dunning et al. (2007) studied in detail the Haitian Bala Landslide, the largest landslide
triggered by October 08, 2005 earthquake. They classified the landslide as “Rock
Avalanche”, measured various parameters and gave their quantitative data such as length,
width, area and volumes of landslide deposit and dammed lakes respectively.
o Munir and Mirza (2007) worked on the stratigraphic aspects of the 2005 earthquake and
concluded that the decollement is marked by the under lying shales of Juliana Formation.
He also identified two unconformities during this study.
o Kaneda et al. (2008) mapped in detail the surface rupture of causative fault of Kashmir
earthquake 2005. Vertical separation of ~ 7 m was recorded by them and declared that
this fault is not accommodating the main Himalayan contraction because they calculated
the shortening rate and recurrence interval for this fault to be 1.4-4.1 mm/yr. and 1000-
3300 years, respectively.
o Monalisa et al. studied the Indus Kohistan Seismic Zone (IKSZ) as main source of
08.10.2005 Kashmir-Hazara earthquake and aftershocks.
20. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
15
8.0 PREVIOUS SEISMOLOGICAL STUDIES
Quittmeyer R. C. and Abul Farah and Jacob K. H. (1979) have grouped the entire area falling in
Pakistan and Azad Kashmir that surrounds the Simly Dam Project into five different
Seismotectonic Provinces as listed below:
1. Pamir-Karakorum Province.
2. Hazara Region Province.
3. Himalayas Province.
4. Salt Range Province.
5. Indus Basin Province.
8.1 Pamir-Karakorum Province
The Pamir-Karakorum Province is located along a portion of the southern boundary of the
Eurasian plate and north of the Indus suture Main Mantle Thrust (MMT). It encompasses the
Main Karakorum Thrust (MKT).
Teleseismic activity within this Province is of moderate level. This activity is mostly aligned in a
north-easterly direction, paralleling the large scale structural trends of the region. However, some
northwest thrusting trends are also found in this region (Chandra 1978). Along the Karakorum
Thrust the level of seismic activity is reasonably low.
Based upon study of LANDSAT imagery, recent fault movement for part of this Province have
also been reported (Kazmi 1979). However, this Province does not have any impact on the safety
of the Simly Dam Project.
8.2 Hazara- Region Province
The Hazara-Region Province encompasses mostly eastward trending folds and faults of the
Northern Pakistan. The deformation within this zone is primarily the result of collision between
the Indo-Pakistan and the Eurasian plates (Seeber & Jacob 1978).
Historical data indicate that moderate to large earthquakes causing significant damage have
occurred in this Province a number of times in the past.
Seismically defined faults within the Hazara-Region Province have been identified using micro
seismicity data. Shallow seismicity within the Hazara-Region Province occurs on perpendicular,
steeply dipping faults characterized by reverse and strike-slip faulting. Teleseismically located
seismic events, however, do not align with any of the mapped surface faults in the Hazara-
Region Seismotectonic Province. As the mapped faults are dominantly thrust type, a narrow
21. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
16
alignment of epicentres along them is not to be expected. Furthermore, some activity may be
associated with faults that are located below the possible decollement surface at a depth of about
12-15 km, and that do not have any surface expression. Occurrence of some earthquakes
following the dominant structural trend, however, suggests that they be associated with the major
mapped faults in this Province.
8.3 Himalayas Province
The Himalayas Province represents one of the primary compressional features that have resulted
from the collision of the Indo-Pakistan subcontinent with Eurasia. This zone of deformation is a
result of folding and thrusting associated with the development of large nappe structures and
deep crustal shortening (Gansser 1964). The Himalayas trend in a south-east direction from the
Hazara Kashmir Syntaxis. Many mega tectonic features including Main Central Thrust (MCT),
Punjal Thrust (PT), Main Boundary Thrust (MBT) and Jhelum Thrust (JT) etc. are located in this
seismotectonic Province (Figures 4 & 5).
Seismicity recorded within this Seismotectonic Province is of moderate to high level. Most of the
earthquakes in this province are associated with the frontal zone of deformation. They are
located parallel to and northeast of the surface trace of the main frontal thrust. One great
earthquake of 1905 having magnitude Ms = 8.0 and located near Kangra was also generated in
this Province (Gutenberg & Richter 1956). That event, ruptured 250-300 km portion of the
ground surface along the main frontal thrust (Middlemiss 1910).
The Simly Dam Project site falls in this Himalayas Seismotectonic Province.
8.4 Salt Range Province
The Salt Range Province is situated south of the Hazara Seismotectonic Province and extends
from the Suleiman Range on west to the Himalayas in the east. General orientation of the range
is east-northeast, but prominent southeast trending transverse features offset parts of it. This
Province is composed of folded and faulted thrust sheets and represents thin-skinned internal
deformation within the Indo-Pakistan plate resulting from its own collision with Eurasia.
This Province is characterized by a very low-level of modern Teleseismic activity, in contrast to
other parts of the frontal zone of Pakistan. It also has no known history of rupture in moderate or
large magnitude earthquakes. Micro-earthquake studies indicate, however, that at low magnitude
levels (Mb < 4) the entire Salt Range is active, especially along transverse faults at points where
the Salt Range offsets (Seeber & Jacob 1976).
22. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
17
8.5 Indus Basin Province
The Indus Basin Province is located within the Indo-Pakistan plate south of the Himalaya
Province and east of the Salt Range Province. Seismicity within this zone occurs at a low level.
Although infrequent, some events have caused considerable damages. Seismic activity within the
Indus Basin Province may be related to bending of the Lithosphere (Molnar 1973). Focal
mechanism for some events near New Delhi showed normal faulting on one of two nodal planes
parallel to the Himalayas. Surface faults have not been mapped in the Indus Basin Province; the
extensive alluvial cover has buried any structural evidence of faulting.
9.0 EARTHQUAKE CATALOGUE
Earthquakes are generated by tectonic process in the upper part of the earth called lithosphere
that is divided into several rigid parts called as “Plates”. Due to movement of these plates, stress
build up takes place and results in the deformation of the crustal mass. This energy accumulation
gives birth to seismic events. The contact zones between adjacent plates are, therefore,
considered as most vulnerable parts from the seismic hazard point of view. Islamabad-
Rawalpindi area is located near the contact zone between the Indian plate and the Eurasian plate.
This contact represented by the Himalayas has always been generating moderate to large
earthquakes including Kangra (1905), Bihar-Nepal (1934) and Assam (1897) earthquakes that
have left their landmarks in the history. The information about earthquakes in this region is
available in two forms i.e. historically recorded and instrumentally recorded earthquakes. The
instrumentally recorded earthquake data is available only since 1904. Before this, the source of
earthquake information is through the historical records and published literature.
For the present Seismotectonic and Seismic Hazard Evaluation studies, catalogues both of
Historical as well as Instrumental Earthquakes was prepared.
9.1 Pre-Instrumental Seismicity
Pre-Instrumental Seismicity data is a good helping tool for assessment of the maximum
magnitude or the maximum Intensity (MM Scale) that has occurred in the past and could re-
happen in the future near some sites of interest. Compilation of historical earthquake data helps
to identify the seismicity patterns of an area and, in regions where numerous earthquakes have
occurred, provides a basis for estimating the probability of future earthquake motion at the site
considered. This is based on the assumption that events similar to those which have occurred in
the past could reoccur at or near the same location.
Compilation of historical earthquake data helps to identify the seismicity patterns of an area and
provides a basis for estimating a lower bound of the severity of possible future earthquake
motion at the site considered. The lack of historic earthquakes, however, does not necessarily
23. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
18
imply that the area considered is aseismic. To obtain data that have not been instrumentally
recorded it is sometimes necessary to perform a thorough search of the technical literature,
newspapers and journals, public and private sources of earthquake information and to catalogue
such historical events within the fault study area that may have had an effect on the Project site.
For the preparation of catalogue of Historical Earthquakes, help was taken from following three
sources:
1. Documentation of Amateur Seismic Centre (ASC India).
2. Compilation of Earthquake Intensity data by M/S Nespak.
3. Compilation of Maximum Intensity data from Tarbela Seismic Observatory.
Based upon records of these three sources, a comprehensive Catalogue of almost all the
significant earthquakes located in the entire Region was prepared (Annexure-I). This Catalogue
provided an account of loss of life and damages to property/infrastructure and the maximum
Intensity experienced in the area from the year as early as 4th
Century BC. Compilation of
historical earthquake data helps to identify the seismicity patterns of an area and, in regions
where numerous earthquakes have occurred, provides a basis for estimating the probability of
future earthquake motion at the site considered. This is based on the assumption that events
similar to those which have occurred in the past could reoccur at or near the same location.
Many of those earthquakes with precise locations and magnitudes occurred within the region of
two degree radius from the Simly Dam site. From the Composite Historical Catalogue it was
concluded that Simly Dam Project area and surroundings have experienced Intensity VIII to IX
many times in the past. About fourteen significant events having magnitudes more than 5.0,
occurred from 1828 till 1972 within the Seismotectonic Province where the Simly Dam Project is
located. Appendix-I give Catalogue of Pre-Instrumental documented earthquakes.
9.2 Catalogue of Felt Earthquakes
A catalogue of earthquakes (compiled by Tarbela Seismic Observatory, around 50 km south-
west of the Simly Dam site that were felt at Islamabad, Tarbela, Abbottabad and Muzaffarabad
area and occurred from 250 AD till 2013 has also been included in the present Seismotectonic
and Seismic Hazard Analysis (SSHA). The catalogue contains magnitudes Mw from 3.0 to 8.6,
equating to Seismic Intensity II to XI on MM Scale. It is observed even some earthquakes with
magnitudes Mw = 3.5 were felt with Intensity of around III to IV at the Simly Dam Project area.
The Mw = 7.6 devastating Kashmir-Hazara earthquake of October 08, 2005 generated an
Intensity of XI at Muzaffarabad about 75 km off Simly Project while its Intensity at Simly Dam
Project was computed as VII-VIII. Catalogue of felt earthquakes at Simly Sam Project site is
given in Appendix-II.
24. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
19
9.3 Instrumental Seismicity
The instrumental recording of earthquakes started in 1904. The number of seismic stations
remained small in South Asian region until 1960 when the installation of high quality
seismograph under World Wide Standard Seismograph Network (WWSSN) increased the quality
of earthquake recording.
The Micro Seismic Studies Program (MSSP) of WAPDA, Tarbela, has a network of twenty nine
field seismic stations spread all over the area around Tarbela dam project and in the Northern
Pakistan. It is a right hand rule that quality of interpreted seismic events improve with the
number of stations around an area and with the availability of noise free data. In order to carry
out the study in hand a comprehensive catalogue of earthquakes since 1927 has been prepared.
Seismic data from Tarbela and Mangla Seismic Networks, USGS (United States Geological
Survey) and ISC (International Seismological Centre) has been merged to accomplish the task.
The total number of earthquakes in the master catalogue from 1927 to 2013 is more than twenty-
five thousand. For the entire practical reasons a catalogue of earthquakes with magnitudes ≥ 3 in
an area around two hundred kilometres from Simly Dam Project for the years from 1960 to 2013,
contributing earthquakes has also been taken into account.
Reporting agencies have given a variety of magnitudes viz: body wave magnitude (Mb), surface
wave magnitude (Ms), Richter/Local magnitude (Ml) or duration magnitude (Mo) etc. Since
attenuation relationships are based on magnitude of given type, a single type must be selected
(Usually Mw). Therefore for data to be used in Seismotectonic and Seismic Hazard Analysis
(SSHA), all the magnitudes were converted to moment magnitude (Mw) by the equations given
below. Conversion from Ms and Mb to Mw was achieved through latest equation suggested by
Scordilis (2006):
Mw = 0.67 Ms + 2.07 for 2.5 ≤ Ms ≤ 6.1……………………..1
Mw = 0.99 Ms + 0.08 for 6.2 ≤ Ms ≤ 8.2……………………..2
Mw = 0.85 Mb + 1.03 for 3.5 ≤ Mb ≤ 6.2……………………..3
For Ml up to 5.7, the value of Ml was taken = Mw as suggested by Idriss (1985). Conversion of
Ml to Mw beyond magnitude 5.7 was done by using equations on next page suggested by
Ambraseys and Bommer (1990).
0.82 (Ml) – 0.58 (Ms) = 1.20 …………………………………4
Log Mo = 19.09 + Ms for Ms < 6.2………………...…5
Log Mo = 15.94 + 1.5 Ms for Ms > 6.2………………...…6
Mw = (2/3) Log (Mo) – 10.73…………………………..……7
25. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
20
9.3.1 February 14, 1977
An earthquake with maximum intensity of VII occurred about 7 km northeast of Rawalpindi and
cause damage in 20 villages. In village Kuri, Malot and Pindi Begwal around Nilour most of the
Katcha houses were either collapsed or damaged. The acceleration recorded at Nilore in
Islamabad due to this magnitude 5.2 earthquake was 0.2 ‘g’.
9.3.2 Kashmir-Hazara Earthquake of October 08, 2005
The Kashmir Hazara earthquake of 8th October 2005 (Mw 7.6) occurred in the Kashmir region.
WAPDA Microseismic Observatory with seismic stations operating in the area reported the
epicentre of this earthquake in the Kashmir Hazara Syntaxis. Aftershocks of the earthquake lie
NW of the main shock epicentre in the Indus Kohistan Seismic Zone (IKSZ). The earthquake
occurred at the western extremity of the Himalaya, where the arc joins the Karakorum, Pamir,
and Hindukush ranges Figure-7.
This earthquake occurred along pre-existing active faults. The newly deformed area occupies a
120 km long northeast trending strip extending from Balakot, Pakistan, southeast through Azad
Kashmir. It cuts across the Hazara Syntaxis, reactivating the Tanda and Jhelum Thrust faults.
North of Muzaffarabad the surface rupture coincides approximately with the MBT, on the south-
western flank of the Syntaxis. The fault offset was 4 m on average and peaks to 7 m northwest of
Muzaffarabad. The rupture lasted for 25 s and propagated up dip and bi-laterally with a rupture
velocity of about 2 km/s (Philippe et al. 2006). The heavily damaged area north of Muzaffarabad,
Kashmir shows the maximum deformation. There are known active faults stretching to the
northwest and southeast near the epicentre, which reveal some uplift on the northern side and
dextral, right-lateral strike-slip activities (Fujiwara et al. 2006). The known active faults are
divided in two fault groups, the Jhelum Thrust fault, northwest of Muzaffarabad and the Tanda
fault, southeast of Muzaffarabad (Nakata et al.1991).
Seismically, the most active geological structures of this region are considered to be capable of
generating large events. In the NW Himalayas, prior to 2005, there is no report of surface
rupture on a causative fault of any earthquake. Thus, one may conclude that the NW Himalayan
earthquakes are due to a blind fault zone, such as the IKSZ. However, the Kashmir Hazara
earthquake is the first of its kind to show the surface rupture of 2- to 5-m displacement. This has
been observed through the field studies and SAR data. The 120 km long rupture zone passes
through Balakot, Muzaffarabad, Rajkandi, Sarain, and Suddangali and dies out in the NW of
Balakot and SE of Suddangali to Bagh (Figure-7) (Mehdi 2008 & 2010).
The Kashmir Hazara earthquake is not only the deadliest of all the Himalayan earthquakes but it
may also have triggered the largest number of landslides (more than 100) in the area. Most
26. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
21
earthquakes occurred along the active faults, whereas NW trending linear landslides are observed
more commonly in the hanging wall of the Jhelum Thrust Fault. The Focal Mechanism Solution
(FMS) of main shock and many aftershocks suggest that the Indus Kohistan Seismic Zone
(IKSZ) got activated and was the source of the Kashmir Hazara earthquake of October 08, 2005.
10.0 SEISMOTECTONIC & SEISMIC HAZARD ANALYSIS (SSHA)
The Simly Dam-Islamabad area is located close to the northern edge of the Potwar plateau where
its meets with the Margalla range. The extension of the MBT on the western side of the Hazara-
Kashmir syntaxial bend passes north of the area.
Due to the movement of the Indian plate towards north, compressive stress is being developed on
the faults of the area which are predominantly thrust in nature. This stress is being released in the
form of small to moderate earthquakes but neo-tectonic studies of the faults of the area show that
major earthquakes with large return periods are possible in this area. The features of deformation
of Quaternary deposits observed in the Islamabad-Rawalpindi area and its vicinity indicate the
movement of faults during the Holocene period which indicates that faults should be considered
as seismically active.
The plots of instrumentally recorded seismicity (Fig. 8, 9 & 10) shows that the Simly-Islamabad
is located in seismically active region, with High to Very High level of seismicity. In general,
however, the number of recorded earthquake is more towards north and decreases towards south.
The cluster of events north of Simly-Islamabad is the aftershocks of the recent October 08, 2005
devastating earthquake centered near Muzaffarabad.
The study of this seismic data record since 1927 (Appendix-III) indicates that the area lies in an
active tectonic belt where several moderate earthquakes have been located. Seismicity Map for
this instrument data is presented in Figures 8, 9,& 10. There are several active faults displayed
on this map. Mostly the seismic events seem to have aligned along the faults. The area in these
plots is called as Simly Seismic Region (200 km radial distance around Simly Dam Project site).
Also displayed on these plots is the location of devastating Mw = 7.6 Kashmir-Hazara
earthquake that originated on October 08, 2005. Mostly the concentration of the aftershocks
related with the mega earthquake is along the Indus Kohistan Seismic Zone (IKSZ). The IKSZ
was later declared as the source of Kashmir Hazara earthquake (Mehdi 2012). The plots also
indicate a lot of moderate level of seismicity is associated with MBT and other faults of Hazara
Thrust System just north of Islamabad. Towards south many epicentres can be associated with
faults of Potwar and Salt Range areas.
27. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
22
The shallow depth (i.e. <30 km.) in the plots is showing that earthquake forces are more active at
this depth indicating a severe earthquake hazard within this region. Moreover, the seismicity
pattern, in most of the cases follows the mapped surface trend of the structures present in the
area.
Towards north of Simly Dam Project, seismic could be associated with Main Mantle Thrust
(MMT), towards northwest Hindukush seismic zone is present in which some recent earthquakes
resulting in some damage at Islamabad have been recorded.
Around Simly Dam Project, a lot of seismic activity has been recorded which could be associated
mostly with Hazara Kashmir Syntaxis (HKS), Main Boundary Thrust (MBT) Fault zone, Jhelum
Thrust, Jhelum Fault, Muzaffarabad Thrust (MT) and Indus Kohistan Seismic Zone (IKSZ).
Instrumental record (Appendix-III) indicates that the Simly Seismic Region is seismically very
active.
Riasi thrust and MBT in Kashmir are other active features towards northeast of Simly Project
with which lot of observed seismicity is associated. The historical seismicity data suggests that
intensities up to VII-VIII (on MM scale) have been frequently felt in Islamabad by earthquakes.
The only major earthquake reported to origin near Islamabad is the 25 AD earthquake with
maximum estimated intensity of IX on MM scale which ruined Taxila. A similar earthquake with
epicentre on faults nearer to Islamabad may cause higher intensity at Simly-Islamabad.
Comparison of the seismicity of the Himalayas observed east and west of the Hazara-Kashmir
Syntaxis shows that while several major to large earthquakes have occurred in Himalayas east of
the Syntaxis, only one such earthquake (Taxila earthquake) have been reported to occur west of
the Syntaxis. This suggests that return period of earthquakes west of the Syntaxis is larger as
compared to those on the east of the Syntaxis.
The seismotectonic features that are considered active in the Simly-Islamabad region and thus
critical for the seismic hazard study include:
i) Hazara thrust fault system, consisting of MBT and other associated faults, having
northeast-southwest trend and located north of Islamabad.
ii) Salt Range thrust, Dil Jabba fault, Riwat fault and other associated faults of Salt-Range-
Potwar area, all having NE-SW to E-W trend.
iii) Main Boundary Thrust (MBT) and Riasi thrust and associated parallel faults, having
NW-SE trend, located west of Hazara-Kashmir syntaxial bend, and
iv) Panjal-Khairabad thrust, comprising foreland zone that extends up to MMT towards
north.
28. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
23
The entire region is dominated by thrust type of faults that do have some strike- slip component
at places also. These faults are considered active because of association of observed seismicity
with these faults.
The scope of the Seismotectonic and Seismic Hazard Analysis (SSHA) for a site depends on the
seismicity of a region or site-specific considerations, the types of structures involved, and the
consequences of failure. The design and evaluation of Critical Structures are based on a
comparable level of study and analysis for each phase of the study (seismotectonic, geological,
site, geotechnical and structural investigations) and that level of study should reflect both the
criticality of the structure and the complexity of the analysis procedures.
Critical Structures in zones of low seismicity generally do not require extensive seismic
investigations and analyses unless failure would result in an unacceptable threat to life, property,
or environment. Previous studies, as well as the performance of and experience with existing
Structures, suggest that concrete Structures in regions of low to moderate seismicity, when
adequately designed to withstand the appropriate static forces, have been competent to also
withstand historic earthquakes. Extensive investigations and design analysis may be required if
the consequences of failure are unacceptable where the seismic hazard is high.
For the SSHA of Simly Dam Project site, the prevailing guidelines (2010) provided by the
International Commissions on Large Dams (ICOLD), to select seismic parameters for design of
dams have been followed. Existing practice especially in earthquake prone regions is to carry out
SSHA so that remedial measures may be taken to prevent/lessen damages to Structures. Such
assessment depicting intensity and ground motion parameters like peak ground acceleration,
peak ground velocity and peak ground displacement are increasingly being taken into
consideration by different agencies involved in planning, design and construction of structures.
10.1 Deterministic Seismic Hazard Analysis (DSHA)
The principle of analysis involved in the deterministic approach is to evaluate the critical
seismogenic sources, like capable faults and the identification of a maximum magnitude assigned
to each of these faults. Then with the help of suitable attenuation equations, peak horizontal
accelerations are determined.
As per ICOLD prevailing guidelines for computation of seismic hazard parameters,
Deterministic approach for Seismic Hazard Assessments requires:
i. Identification of all the critical tectonic features that may generate significant ground
motions in the vicinity of the Project site.
ii. Assigning to each of these tectonic features a maximum magnitude on the basis of
key fault parameters. The capability of the faults is ascertained through observation
of historical and instrumental seismic data and geological criteria such as the fault
29. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
24
rupture length to magnitude relationship, or fault movement to magnitude
relationship.
iii. Computing the ground motion parameters at the site associated with each feature as a
function of magnitude and distance. For Dams & Hydropower Project Structures,
most severe combination of maximum magnitude and minimum distance to the
Project site, independent of return period is considered.
10.1.1 Critical features
Seven features have been selected as the critical features for the seismic hazard assessment to the
Simly Dam Project site. The selection is based upon the association of seismicity along each
fault and the geological criteria such as the fault rupture length-magnitude relationships. The
level of seismicity has been considered by observing both the historical and instrumental
earthquake data along each feature. Although the entire region is dominantly representing the
thrust faulting but some strike-slip component is also present. This is the reason that out of
twelve selected faults, nine are thrust and three are strike-slips. All these faults along which
earthquakes can produce the appreciable strong ground motions are shown in Figure-5.
Seismic Aspect of Main Boundary Thrust (MBT) Fault
The Main Boundary Thrust (MBT) is the main frontal thrust of the Himalayan range. From
Assam in the east to Kashmir in the west it runs about 2500 km. This thrust continues north-
westward, turns westward near the apex of the Syntaxis and then bends southward towards
Balakot (Kazmi and Jan, 1997). It dips about 500
to 700
E, northwest of Muzaffarabad (Calkins et
al., 1975) and runs in E-W direction south of the Margalla Hills.
A hairpin-shaped system of faults truncates the Hazara-Kashmir Syntaxis (HKS) both on the east
and western sides (Kazmi and Jan, 1997). Within the MBT fault zone, on the western side of
HKS, the number of thrust faults like Sangargali, Thandiani, and Nathiagali (Hazara) Thrusts is
situated and they dip to the north and northwest (Baig and Lawrence, 1987). Structurally they
overlie each other so that the Sangargali Thrust overlies the Thandiani Thrust and Nathiagali
(Hazara) Thrust lies below the Thandiani Thrust. Nathiagali or Hazara Thrust branches 5 km.
south of Muzaffarabad and forms the northern boundary of MBT fault zone (Antonio, 1991). In
the west of HKS, where the MBT is correlated with the Triassic to Paleocene sequence of the
Kala Chitta Range near Attock, the Nathiagali Thrust can be equivalent to the Hissartang Fault of
Yeats and Husain (1987). On the Kashmir side (i.e. eastern side of Hazara Kashmir Syntaxis)
between MBT in the east and Jhelum Fault in the west, Himalayan Frontal Thrust (HFT) and
Kotli Thrust are situated near Kotli, Himalayan Frontal Thrust and the Kotli Thrust appear in the
north-western direction and run parallel to Jhelum Fault till the Kaghan Valley where the Jhelum
Fault truncates the Himalayan Frontal Thrust (Baig and Lawrence, 1987). The alignment of
epicentres along all these three faults shows that seismically they are active.
30. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
25
This MBT fault zone and the area around HKS is the source of many strongest ever-recorded
earthquakes in the region and therefore represent very high earthquake potential. A series of
large earthquakes have already occurred along this 2400 km long fault and it is capable to
generate seismicity of level of Kashmir-Hazara earthquake of October 08, 2005. These include
1905 Kangra earthquake of M 8.6, 1934 Bihar-Nepal earthquake of M 8.4 and the great Assam
earthquakes of 1897 and 1950. The rupture, which caused these earthquakes, is occurred in the
detachment in the vicinity of the surface trace of MBT (Seeber and Armbruster, 1979).
Seismic Aspect of Punjal Fault
Punjal Fault is a thrust fault, which runs parallel to MBT on the eastern limb of the Hazara-
Kashmir Syntaxis and on the western side it lies over the Sangargali Fault with its nearest
segment passing about 1.61kms from Muzaffarabad (Figure-7). Punjal Thrust curves around the
apex of the Syntaxis then bend southward (Kazmi and Jan, 1997). On both eastern and western
limb of the Syntaxis this fault has different tectonic and stratigraphic setting. Due to this reason
Greco, 1991, has named the Punjal Thrust as Mansehra Thrust on the western side of the
Syntaxis. Further westward it apparently links up with the Khairabad Thrust (Yeats et al. 1987).
However, Baig et al., 1989 the name Mansehra Thrust for another thrust passing close to
Mansehra north of the Punjal Thrust. Therefore in order to avoid this confusion the term
Abbottabad Thrust is used for that part of Punjal thrust passing on the western side of the HKS as
suggested by Baig and Lawrence, 1987. They are also of the opinion that the Mansehra and Oghi
Thrusts are the extension of Balakot shear zone in the Kaghan Valley and both of them are
structurally above the Punjal Thrust.
The macro-instrumental seismic record since 1960 shows that the earthquakes with magnitude
ranging between 4 - 5.5 Mw have occurred along these faults. The seismic data of Tarbela
Microseismic network since 1973 show a lot of seismic activity along the Punjal fault.
Seismic Aspect of Jhelum Fault
This fault too is seismically active and runs about 10 km northeast of the Simly Dam Project.
The October 08, 2005 (Mw = 7.6) earthquake has further reactivated this tectonic feature.
Several instrumentally recorded earthquakes are associated with this tectonic feature. Recent
landslides along this fault have also been observed from Balakot to Mangla. Figure-9 indicates
some concentration of seismic activity along this active fault. The seismicity is observed to align
not only along the mapped portion of the Jhelum fault but also towards north and south of its
mapped length that may indicate its possible extension up to about 236 km. The instrumental
seismic data however, lack Mw > 6 located along this fault (Mehdi 2008 & 2010).
31. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
26
Seismic Aspect of Muzaffarabad Thrust Fault (MTF)
After separation from the western limb of Hazara-Kashmir Syntaxis, Muzaffarabad Thrust fault
(Jhelum Thrust) passes through interior of the Hazara-Kashmir Syntaxis having NW-SE
orientation along the Upper Jhelum River. The MTF has emerged at the surface over a distance
of ~120 km with an earthquake of 7.6 magnitudes in 2005 proving its seismically active nature
(Singh et al., 2006). The trace of the thrust occupies northern bank of the Upper Jhelum River
from Muzaffarabad up to the village Naushahra. The trace crosses the river at Dhallian, passes
through the Siran village and follows the Baghsar Katha towards Chikar.
The earthquake of October 08, 2005 followed the April 04, 1905 earthquake about after 100
years. Such an earthquake was inevitable and had qualitatively as well as quantitatively been
foretold by some Researchers.
The vengeance of the anticline towards southwest suggests an inherited steepness of the upright
to overturned western limb, which in essence is a thrust fault, most appropriately can be termed
as the Hazara Thrust (Calkins et al., 1975). It marks the western contact of the Muzaffarabad
Formation with the Murree Formation at the western limb of the Muzaffarabad anticline. It dips
at 25o
-50o
towards NE and is exposed immediately east of Muzaffarabad. Muzaffarabad Thrust is
refolded along the Neelum River near Nisar camp area, before it extends towards the Balakot in
the NW, where it joins MBT and Punjal Thrust at the western limb of the Hazara-Kashmir
Syntaxis (HKS).
To the southeast, the Muzaffarabad Thrust was previously not mapped beyond the termination of
exposures of the Muzaffarabad Formation. Nakata et al. (1991) did show an active fault along
the upper Jhelum River between Muzaffarabad and Garhi Dopatta, which he termed as the Tanda
Fault. The 2005 Kashmir Earthquake ruptured the Jhelum Thrust along with its south-eastern
extension (Tanda Fault) between Balakot in the NW to Bagh in the SE, thus establishing the
existence of a major thrust in an over 120 km stretch. Unlike Jhelum Fault, the Muzaffarabad
Thrust did not show sharp contact in the field, rather it covers a broad zone. One of its reasons is
that it separates the same lithology.
Seismic Aspect of Indus Kohistan Seismic Zone (IKSZ)
On the basis of a micro-earthquake survey in this region during 1973–1974, a wedge-shaped NW
trending structure was recognized by Armbruster et al. (1978) who named it as the IKSZ. Later
workers (Seeber and Armbruster 1979; Ni et al. 1991) confirmed the presence of this 100- km
long feature between the HKS and the MMT.
This 50-km-wide zone of seismicity has a nearly horizontal upper surface and a NE dipping
lower surface. Ni et al. (1991), on the basis of relocated hypocentres, have identified two seismic
32. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
27
zones within the IKSZ: a shallow zone extending from the surface to a depth of 8 km and a more
pronounced midcrustal zone lying at depths of 12 to 25 km. The upper boundary at a depth of
about 12 km is considered to represent a decollement surface that decouples the sediments and
metasediments from the basement.
The IKSZ is seismically the most active structure in the region, as it is capable of generating
large events. It is predominantly a thrust fault with a NW-striking and NE-dipping plane parallel
to the general trend of the MBT to the SE of Muzaffarabad. However, one cannot equate the
IKSZ with the MBT because of their different tectonic history, as based on surface geology
(Gahalaut 2006). The MBT and the Hazara thrust system (HTS) are among the many structural
units. The structural complexities arise when Armbruster et al. (1978) argue that the MBT does
not extend past the HKS to join the IKSZ.
Prior to 2005, the most destructive earthquake, associated with the IKSZ, was the 28 December,
1974 Pattan earthquake with mb 6 magnitude. Seeber et al. (1981), however, proposed a shallow
dipping seismically active detachment under the Outer and Lesser Himalayas from the steeper
and mostly aseismic basement thrust under the Higher Himalayas that extends further north past
the HKS. This 200- to 300-km width detachment joins IKSZ and extends northward beyond it.
The question arises whether the IKSZ or the detachment is responsible for the Muzaffarabad
earthquake.
10.1.2 Maximum Credible Earthquake (MCE)
According to International Committee On Large Dams (ICOLD) guidelines, the Maximum
Credible Earthquake (MCE) is the largest reasonable conceivable earthquake that is possible
along a recognized fault or within a geographically defined tectonic province, under the presently
known or presumed tectonic framework.
The MCE for each potential earthquake source, judged to have a significant influence on the site,
is established by a DSHA based on the results of a seismotectonic study (site-specific
investigations and/or literature review). The MCE for each seismotectonic structure or source
area within the region examined is defined preferably by magnitude. However, in some cases it
may be defined in terms of epicentrial Modified Mercalli Intensity, distance, and focal depth.
Earthquake recurrence relationships (i.e., the frequency of occurrence of earthquakes of different
sizes if appropriate for the fault) are also established for the significant seismic sources. For
source zones consisting of random seismicity, an MCE can be determined by finding the
magnitude and distance that best matches the equal hazard response spectrum from a PSHA in
the frequency range appropriate for the structure. Judgments on activity of each potential fault
source are generally based on regency of the last movement.
33. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
28
For high-hazard potential dams and related structures, movement of faults within the range of
35,000 to 100,000 years BC is considered recent enough to warrant an "active" or "capable"
classification. All of the above MCE assessments for the various earthquake sources are
candidates for one or more controlling MCEs at the site. It is also important to look at
earthquakes that have a long duration but not necessarily the highest peak acceleration at the site.
10.1.3 Maximum Earthquake Potential
The methods assigning a maximum potential magnitude to a given active fault based on
empirical correlations between magnitude and key fault parameters such as fault rupture length,
fault displacement and fault area (Idriss, 1985).
Selection of a maximum magnitude for each source, however, is ultimately a judgment that
incorporates understanding of specific fault characteristics, the regional tectonic environment,
similarity to other faults in the region and data on the regional seismicity. The maximum
earthquake magnitude of each of the fault was calculated considering the following seismic
relationships:
1. Wells & Coppersmith (1994)
Mw = 5.02 + 1.22 Log L (Here L = Rupture length in Km.)…………….8
2. Nowroozi A. (1985)
Ms = 1.259 + 1.244 Log L (L = Rupture length of fault in meters)………..9
3. Simmons, D. B. (1982)
Ms = 2.021 + 1.12 Ln L (L = Rupture length of fault in Km.)………….10
4. Bonilla et. al. (1984)
Ms = 6.04 + 0.708 Log L (L = Rupture length in km.)…………………...11
34. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
29
Results obtained are summarized in the following Table.
Seismic Feature Type
Expected
Rupture Length
km
Maximum Credible Earthquake = Mw
Wells &
Coppersmith
1994
Nowroozi
1985
Simmons
1982
Bonilla
1984
MBT Reverse 150 7.8 7.8 7.7 7.8
Punjal Fault Reverse 150 7.5 7.6 7.7 7.5
MTF Reverse 120 7.8 7.5 7.3 7.3
HKS Reverse 50 7.0 7.0 6.9 6.8
IKSZ 150 7.8 7.6 7.5 7.5
Jhelum Fault Strike-slip 100 7.5 7.5 7.7 7.8
Darband Fault Reverse 40 6.6 6.8 6.4 6.9
10.1.4 Attenuation Equation Relationships
The strong-motion attenuation relationship depicts the propagation and modification of strong
ground motion as a function of earthquake size (magnitude) and the distance between the source
and the site of interest.
The peak horizontal accelerations calculated by deterministic approach are largely affected by
the choice of the maximum magnitude of an earthquake that can occur within the certain critical
feature. The procedure followed in assigning the maximum potential magnitude of an earthquake
depends upon the maximum magnitudes of earthquakes experienced in the past, the tectonic
history and the geodynamic potential for generating earthquakes.
In the present study, peak horizontal accelerations have been calculated using seven available
attenuation equations as shown in Table below. Among them the equation of Boore et al., 1997
have been preferred due to the two reasons. Firstly, this equation is based on a high quality data
set and including the term specifying for reverse faulting, which is the dominant mechanism of
earthquakes in this region. Secondly the same equation can also be used for earthquakes of focal
depth > 30 km i.e. both for the shallow as well as for the intermediate earthquakes.
Thus in the present case, the maximum potential magnitudes of six faults and one zone
calculated on the basis of 50 % of total length and using available relationship by Wells and
Coppersmith (1994). Next Table gives all these active faults present near Muzaffarabad, their
total length, rupture length and maximum potential magnitudes calculated in the present study.
35. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
30
The peak horizontal accelerations were computed assuming that maximum earthquake along a
fault occurs at the shortest distance of this fault from the site. For attenuation laws, which take
into account focal depth also, acceleration values have been computed for focal depth of 10 km.
1. Joyner & Boore (1981)
log y = α + βM − log r + br where r = (d2 + h2 )1/2………………12
2. Sadigh et al. (1987)
ln y = a + bM + c1(8.5 – M)c2 + dln [r + h1 exp (h2M)] ……………………13
3. Ambraseys & Bommer (1991)
log a = α + βM − log r + br……………………………………14
4. Campbell & Bozorgnia (1993)
ln(Y)=β0+a1 M+β1 tanh[a2(M−4.7)]−ln(R2+[a3exp(a1M )]2)1/2
− (β4 + β5M )R + a4F + [β2 + a5 ln(R)]S + β3 tanh(a6D)……..15
5. Ambraseys et al. (1996)
ln Y = C1 + C2M + C3r + C4 log(r) + σP……………………………....……16
where Y is the parameter being predicted, in our case peak horizontal ground
acceleration in g,
Boore et al. (1997)
log Y = b1 + b2(M − 6) + b3(M − 6)2 + b4r ……………….…...17
+ b5 log r + bV (log VS − log VA)
6. Tromans & Bommer (2002)
log y = C1 + C2Ms + C4 log r + CASA + CSSS ………………………………….…………………18
where r = (d2
+ h0
2
)1/2
Peak Horizontal Accelerations (PHA) were computed assuming that maximum earthquake along
a fault occurs at the shortest distance of this fault from the site. For attenuation laws, which take
into account focal depth also, acceleration values have been computed for focal depth of 10 km.
36. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
31
Seismotectonic
Feature
Max. Mw
Magnitude
MCE
Closest
Dist. To
Fault km
Computed Accelerations
‘g’ Median 50 percentile
1 2 3 4 5 6 7
MBT 7.8 15 0.55 0.70 0.55 0.40 0.45 0.45 0.58
Punjal 7.5 25 0.51 0.56 0.41 0.39 0.32 0.34 0.46
MTF 7.8 40 0.56 0.63 0.52 0.43 0.44 0.48 0.52
HKS 7.0 20 0.48 0.51 0.37 0.32 0.31 0.27 0.44
IKSZ 7.6 50 0.26 0.33 0.20 0.35 0.26 0.38 0.32
Jhelum Fault 7.5 10 0.29 0.35 0.34 0.33 0.32 0.35 0.39
Darband Fault 6.6 60 0.15 0.22 0.48 0.15 0.22 0.45 0.48
10.2 Probabilistic Seismic Hazard Analysis (PSHA)
The estimation of PGA has also been carried out using the Probabilistic Seismic Hazard Analysis
(PSHA). The conventional approach has been adopted for the Simly Dam Project site. PSHA is
denoted by the probability that ground acceleration reaches certain amplitudes or seismic
intensities exceeding a particular value within a specified time interval. The inverse of
probability of exceedance is known as the return period for that acceleration and is used to define
the seismic hazard. In PSHA, the seismic activity of seismic source (line or area) is specified by
a recurrence relationship, defining the cumulative number of events per year versus their
magnitude. Distribution of earthquakes is assumed to be uniform within the source zone and
independent of time. Seismic hazard calculated for different sites can be used to generate maps
or curves (hazard curves) with ground accelerations expected with a given probability for a
specified interval of time.
Each seismic zone is split into elementary zones at a constant distance from the site of interest.
Integration is carried out within each seismic zone by summing the effects of various elementary
zones taking into account the attenuation effect with distance. The total hazard is finally obtained
by adding the influence of various seismic zones. The results are expressed in terms of
probability of exceedance of ground motion within the Project life.
10.2.1 Frequency Magnitude Relationships
Richter C. R. (1958) developed the simplest form of earthquake recurrence equation used in most
of the engineering applications as given below:
Log N (m) = a – b (M)…………………………………………….19
The basic assumption for using this relationship is spatial and temporal independence of
occurrence of all the earthquakes being studied for seismic hazard evaluations. Coefficients ‘a’
37. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
32
and ‘b’ can be derived from seismic data relative to the source of interest. Coefficient ‘a’ is
related to the total number of events occurred in the source zone and depends on its area, while
‘b’ represents the coefficient of proportionality between log N (m) and the magnitude. With this
relationship cumulated number of earthquakes occurred in a given period of time can be
approximated. As discussed in previous section a data base of all the earthquakes located within
200 radial distances off Simly Dam Project from 1927 to 2013, was used in these computations.
10.2.2 PGA Computations
In the present work, six seismic source zones and their seismic hazard parameters have been used
for the estimation of PGA using PSHA. The calculation of PGA involves the use of an
appropriate attenuation equation. In the present case the attenuation equation Boore et al 1997
have been used. An attenuation equation is the mathematical/statistical relationship that
correlates the ground acceleration to magnitude and distance, and needs strong motion data.
Due to lack of the strong motion data, Pakistan does not have an attenuation equation of its own.
The relationships of other countries with similar tectonic and geological conditions as those of
our region are usually employed in seismic hazard assessment. In the present case the attenuation
equations of Ambraseys et al and Boore et al have been used. Bommer in his detailed work on
attenuation equations for Pakistan concluded that there are no equations available even from the
neighbouring countries that can be adopted for Seismic Hazard Analysis. For northern Pakistan,
he selected the attenuation equation of Boore et al that has been derived from western North
America. In the present study also, the same equation has been used for the PGA calculations
based upon the fact that it is valid for crustal earthquakes and for thrust/reverse faults, which are
the dominant mechanisms of the study area. The equation of Ambraseys et al has been used for
the sake of comparison only. Both these equations are again reproduced below:
ln Y = C1 + C2M + C3r + C4 log(r) + σP………………………………….20
ln (Y) = b1 + b2(M – 6) + b3(M – 6)2
+ b5lnr + bvlnVS,30/VA,………..…21
Following the normal practice, the PGA values with 10% probability of exceedance in the 50
years, i.e., the return period of 475 years, are calculated. PGA values of 0.35 ‘g’ have been
obtained using Boore et al., 1997 equations.
10.2.3 Seismic Source Modelling
For the definition of seismic sources, either line (i.e. fault) or area sources can be used for source
modelling. Because of uncertainty in the epicentre location, it is always not possible to relate the
located earthquakes to the faults and to develop recurrence relationship for each fault and use
them as exponential model. The Simly Dam Project seismic zone (200 km radial distance from
38. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
33
the site) was therefore divided into six area source zones (area sources) based on their
homogenous tectonic and seismic characteristics, keeping in view the geology, tectonics and
seismicity of each area source zone. These source zones are displayed in Figure-11.
Each of these area sources was assigned a maximum magnitude based on recorded seismicity
and potential of the faults within the zone and a maximum magnitude based on threshold
magnitude observed in the magnitude frequency curve for the zone. As the shallow earthquakes
are more concern to the seismic hazard, the minimum depth of the earthquakes is taken as 5 to 15
km.
Seismic parameters attached to the six zones (Figure-11) were:
i. Recurrence relationship relating the number of events for a specific period of time
with magnitude.
ii. The maximum earthquake giving an upper bound of potential magnate in the
zone.
iii. An attenuation relationship representing the decrease in acceleration with time.
The maximum magnitude for each zone was assessed through the earthquakes given in the
Historic as well as Instrumental Data Catalogues. As the shallow earthquakes are of more
concern to seismic hazard, the minimum depth of earthquakes was taken as 10 km for all the
sources. Computed parameters for the zones are as under:
Table: Source zone parameters for Probabilistic Hazard Analysis
Sr.
#
Seismic
Source
Zone
Dist.
From
Simly
(km)
% of
Eq. Above
Min.
Mag.
Min.
Mag.
(Mw)
Activity
Rate
per Year
‘b'
Value
MCE
Mag.
(Mw)
Min.
Accl.
At
Simly
cm/sec2
1 Zone-1 20 58.5 4.2 6.7 1.32 7.8
3
797
2 Zone-2 35 18.4 4.6 9.2 0.85 7.8 342
3 Zone-3 45 27.9 4.2 5.3 0.82 7.4 288
4 Zone-4 80 22.3 4.0 4.4 0.85 6.6
6.7
76
5 Zone-5 55 29.6 4.3 5.8 0.92 7.6 271
6 Zone-6 95 69.2 4.2 5.3 1.49 7.1 90
39. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
34
11.0 SAFETY EVALUATION EARTHQUAKE (SSE)
The Safety Evaluation Earthquake (SEE) is the earthquake that produces the maximum level of
ground motion for which a structure is evaluated. The SEE may be set equal to the MCE or to an
earthquake less than the MCE, depending on the circumstances. Factors to consider in
establishing the size of SEE are the hazard potential classification of the dam (FEMA 1998),
criticality of the Project function (water supply, hydropower, flood control, etc.), and the
turnaround time to restore the facility to operability.
In general, the associated performance requirement for the SEE is that the Project performs
without catastrophic failure, such as uncontrolled release of a reservoir, although significant
damage or economic loss may be tolerated. If the dam contains a critical water supply reservoir,
the expected damage should be limited to allow the Project to be restored to operation in an
acceptable time frame. This is the earthquake that produces the maximum level of ground motion
for which a structure is to be designed or evaluated.
12.0 COMBINING SEISMIC HAZARD ANALSIS
As per USA Federal Guidelines for Dam Safety (2005), combined application of deterministic
and probabilistic seismic hazard analyses is an effective approach for determining the MCE and
PGA ground motions. The probabilistic analysis allows the probabilities or return periods for
exceeding different levels of site ground motion to be evaluated. This information can then be
used to complement the deterministic analysis.
12.1 Selection of Peak Ground Acceleration (PGA)
According to International Committee on Large Dams (ICOLD) guidelines, the Maximum
Credible Earthquake (MCE) is the largest reasonable conceivable earthquake that is possible
along a recognized fault or within a geographically defined tectonic province, under the presently
known or presumed tectonic framework. It is that event which could produce the maximum
vibratory ground motion against which the water retaining or other critical structures are
designed, and may undergo some displacements but remain functional, while several other
structures may be rendered non-functional.
Both Deterministic and Probabilistic approaches indicates that Jhelum Fault and Main Boundary
Thrust (MBT) are the most critical for the Simly Dam Project site. Deterministic computations
have resulted to a maximum of 0.45 ‘g’ horizontal PGA for the MBT and 0.38 ‘g’ for IKSZ
considered critical for the Project.
The Probabilistic approach has yielded maximum horizontal PGA of 0.35 ‘g’ (with 10 %
probability of exceedance in 50 years). Therefore after combining both PGA values 0.38 ‘g’
(horizontal) may be associated with MCE of Mw = 7.8.
40. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
35
The Operation Basis Earthquake (OBE) represents the level of ground motion at which only
minor damage is acceptable. The Dam, appurtenant structures and equipment should remain
functional and the damage from the occurrence of shaking may easily be repairable. OBE is
taken significantly lower than PGA for MCE and usually it is best determined by the
probabilistic approach. The computations show lowest PGA Deterministic values 0.35 ‘g’, while
lowest PGA Probabilistic value is 0.15 ‘g’.
13.0 ESTIMATION OF ACCELERATION RESPONSE SPECTRA
The seismic design/safety of Dams and appurtenant structures depends on the values of Peak
Ground Acceleration (PGA), Acceleration Response Spectra (ARS) and acceleration time
histories. The PGA is also later used for the pseudo-static analysis of structures.
The earthquake ground motions for dynamic analysis, however, should be specified in terms of
response spectra (mainly for linear-elastic analysis) or acceleration time histories, which are
suitable for both linear and nonlinear dynamic analysis.
Response spectra show the maximum value of absolute acceleration, relative velocity, and/or
relative displacement response of single-degree-of-freedom systems with different dynamic
properties, subject to a time dependent dynamic excitation such as earthquake ground motion.
The maximum dynamic response values are expressed as a function of the undamped natural
period for a given damping ratio of the structure.
The values of response spectra can be determined by using standard or site-specific procedures.
Site specific response spectra correspond to those expected on the basis of seismological and
geological calculations using either the deterministic or the probabilistic seismic hazard analysis
method. After the site specific response target spectra is calculated.
A statistical analysis of scaled response spectra of real earthquake records with similar
characteristics as those expected on the dam site have been used to obtain the response spectra.
The analysis values are presented in Figure-15 & 16.
13.1 Response Spectra Based on Statistical Analysis of Strong Motion Data
The general approach used for the calculation of site-specific response spectra based on the
statistical analysis of the strong motion data is described by Kimball (1983). This method
consists of the statistical analysis of a suite of strong motion recordings from earthquakes having
magnitudes and distances ranges representative for the dam site. The records must be selected to
have similar conditions to those of the Project i.e. site conditions, dominant focal mechanism of
earthquakes, distance and magnitude range.
41. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
36
13.2 Scaled Accelerograms
Under strong earthquake ground shaking (e.g. MCE ground motion) the dam may behave
inelastically and may suffer from some damage. For this case the earthquake analysis of dam is
carried out in the time domain. For this purpose the earthquake ground motion has to be
described by acceleration time histories.
As the inelastic response of structures is sensitive to the acceleration time history, it is necessary
to consider at least three different earthquakes in the dynamic analysis. Each earthquake
comprises three component of ground motion.
Acceleration time histories should be developed to be consistent with the previously estimated
site-specific design response spectra. These accelerograms should also have strong ground
motion duration appropriate to the particular design earthquakes.
Scaling Recorded Accelerograms
As the recorded accelerograms obtained at other places have different PGA and response spectra
from the target values, it is common practice to generate the required accelerogram through a
procedure which scales the accelerogram.
The peak ground acceleration value of the scaled accelerogram should be as close as possible to
the peak acceleration calculated for the desired earthquake. The duration of the strong ground
shaking of the scaled accelerograms should be in accordance with the seismic safety level of
MCE. Accordingly, it has been attempted to select such accelerograms for the MCE which have
a significant duration of upto 10 seconds. As far as possible, there should be as much similarity
as possible between geological and seismological conditions at the locations of the selected
records and those of the area under study.
Since no recorded accelerograms of the Pakistan earthquakes is available, the accelerogram data
bank from other parts of the world has been used for this report. It has been attempted to select
most appropriate recorded accelerogram, which are in accordance with the seismic characteristic
of Simly Dam Project.
The scaled and targeted accelerogram spectra are presented in Figures 17 to 19.
42. Seismotectonics & Seismic Hazard Analysis of Simly Dam Project
37
14.0 SAFETY MONITORING
The Simly Dam Project site is situated in the vicinity of active and complex seismic
environment. The seismically active faults are continuously generating earthquakes in and
around the site area. The recent Kashmir Hazara Mw = 7.6 earthquake of October 08, 2005
located about 70 km NNE, was felt at the Project site with an Intensity IX. Under such situations
installation of one Microseismic Station and two additional Strong Motion Accelerographs
(SMA’s) on Rock and Alluvium has become essential, for the purpose of seismic safety
monitoring of the Project. The Microseismic station be connected to WAPDA Tarbela Seismic
Observatory. Routine inspections and data processing of such instruments is required to be
carried out by expert Seismologists.