1) Researchers in Brazil conducted seismic tests in an urban area of Sao Paulo to evaluate shallow seismic reflection techniques for geological/geotechnical investigation.
2) Tests compared different geophone frequencies (28Hz and 100Hz) and couplings (spikes and clay) with hammer and rifle seismic sources.
3) Additional lab tests analyzed geophone responses when coupled with different clay types on a shake table. The best field results used 100Hz geophones coupled with clay or spikes with a hammer source. Lab tests indicated clay coupling works well except for kaolinitic clay.
This 3D seismic survey was conducted over a coal mine reserve area to better define a geologic structure that could adversely impact longwall mining. The survey revealed an abrupt change in coal seam elevation, or "roll", that trends south into the reserve area before turning southeast. It also identified a deeper geologic structure beneath the roll that seismic time-slice sections suggest is a paleochannel meandering in a similar direction to the roll. Integrating borehole and seismic data using computer modeling, 3D block diagrams were generated showing the steep slope on the west flank of the roll that gradually decreases as it turns southeast. The high-resolution 3D seismic data provided valuable subsurface information to mine engineers for longwall panel development planning
Geophysical survey for the risk managementMario Naldi
This document discusses managing risk through geophysical survey methods for due diligence assessments. It describes how non-invasive geophysical surveys such as electromagnetic, ground penetrating radar, and electrical resistivity tomography can identify subsurface hazards cost effectively by mapping buried utilities, tanks, waste, and other underground anomalies before invasive investigations. Large scale surveys identify potential risks while small scale surveys characterize identified anomalies to better inform follow up actions.
Delineation of Hydrocarbon Bearing Reservoirs from Surface Seismic and Well L...IOSR Journals
Hydrocarbon reservoir has been delineated and their boundaries mapped using direct indicators from 3-D seismic and well log data from an oil field in Nembe creek, Niger Delta region. Well log signatures were employed to identify hydrocarbon bearing sands. Well to seismic correlation revealed that these reservoirs tied with direct hydrocarbon indicators on the seismic section. The results of the interpreted well logs revealed that the hydrocarbon interval in the area occurs between 6450ft to 6533ft for well A, 6449ft to 6537ft for well B and 6629ft to 6704ft for well C; which were delineated using the resistivity, water saturation and gamma ray logs. Cross plot analysis was carried out to validate the sensitivity of the rock attributes to reservoir saturation condition. Analysis of the extracted seismic attribute slices revealed HD5000 as hydrocarbon bearing reservoir.
The document discusses using science and technology to monitor land health through a global research project. It proposes establishing sentinel sites across Africa to collect soil samples and characterize properties using infrared spectroscopy and x-ray diffraction. These techniques can rapidly analyze soil organic carbon, minerals, and aggregate stability to provide reliable data on land functional properties and track changes over time.
This document evaluates the use of portable X-ray fluorescence (PXRF) spectrometry to measure soil salinity. 122 soil samples were collected from salt-impacted soils in Louisiana and analyzed using standard laboratory methods and PXRF. Standard analyses included particle size analysis, organic matter content, and electrical conductivity (EC) using a saturated paste. PXRF was used to quantify elemental concentrations. Simple and multiple linear regression models were developed to correlate elemental concentrations measured by PXRF (particularly Cl) to EC values. Both models produced acceptable correlations (R2 values of 0.83 and 0.90) between EC and PXRF data, though multiple regression using additional parameters like sand, clay and organic matter content was recommended
Anisotropic Avo Analysis for Reservoir Characterization in Derby Field Southe...IOSRJAP
Anisotropic AVO analysis for reservoir characterization in Derby field southeastern Niger delta has been investigated. The objective of this study was to investigate the AVO response of shale over gas sandsonisotropic and anisotropic synthetic models and the real CDP gathers. This was done by plotting amplitude of reflections versus offsets and carrying out AVO intercept-gradient analysison HD1horizon. The results of the models were compared with the real CDP gather to deduce the robust synthetic model for efficient AVO analysis in the field. Well, CDP processed gathers and Hampson-Russell GEOVIEW and AVO module were used for the analysis. Results revealed that the plots of amplitude versus offset of the isotropic and anisotropic synthetic models agree at near offset but show opposite AVO response due to increasing contributions of seismic anisotropy at far offsets. The results of the anisotropic synthetic model correlates well with the CDP gathers indicating that seismic anisotropy is an important factor in AVO analysis. Results also show that a bright spot indicative of gas charged sands was delineated for the isotropic and anisotropic models but with different classes of AVO anomalies andproducts. The isotropic synthetic model show a class II AVO anomaly with a positive AVO product, while the anisotropic model show a class IV AVO anomaly with a negative AVO product comparable to the real CDP gather.These analysesclearly show that description of rock without anisotropy especially, seismic anisotropy is incomplete since most rocks are not completely isotropic. Therefore, accounting for seismic anisotropy in AVO synthetic modelling will ensure that the correct earth model is predicted and the reservoir is adequately characterized.
12 reedlunn reinvestigation into closure predictions sand2016 8559leann_mays
Room D was an underground experiment at Waste Isolation Pilot Plant between 1984-1991 that measured rock salt creep around an excavated room. Early simulations underpredicted vertical closure of the room by 4.5x, requiring adjustments to model parameters. Recent interest in Room D has led to updating simulations using today's standards and recalibrating the constitutive model against new salt creep laboratory experiments. The updated model still underpredicts vertical closure, but by a reduced amount of 3.1x. Potential improvements to the model are discussed.
2D MASW ANALYSIS FOR GEOTECHNICAL ENGINEERINGAli Osman Öncel
This document describes a study that used seismic refraction and multi-channel analysis of surface waves (MASW) to investigate near-surface shear wave velocities at a site in Egypt. Seismic refraction was used to determine P-wave velocities down to depths of 30 m. MASW was used to determine 1D and 2D shear wave velocity profiles by analyzing Rayleigh surface wave dispersion. Shear wave velocities obtained from MASW were used to evaluate site response and classify the site according to standard site classifications. The study area consists of Quaternary deposits overlying Tertiary sedimentary rocks. P-wave and MASW surveys were conducted along multiple profiles using geophones and a seismograph to
This 3D seismic survey was conducted over a coal mine reserve area to better define a geologic structure that could adversely impact longwall mining. The survey revealed an abrupt change in coal seam elevation, or "roll", that trends south into the reserve area before turning southeast. It also identified a deeper geologic structure beneath the roll that seismic time-slice sections suggest is a paleochannel meandering in a similar direction to the roll. Integrating borehole and seismic data using computer modeling, 3D block diagrams were generated showing the steep slope on the west flank of the roll that gradually decreases as it turns southeast. The high-resolution 3D seismic data provided valuable subsurface information to mine engineers for longwall panel development planning
Geophysical survey for the risk managementMario Naldi
This document discusses managing risk through geophysical survey methods for due diligence assessments. It describes how non-invasive geophysical surveys such as electromagnetic, ground penetrating radar, and electrical resistivity tomography can identify subsurface hazards cost effectively by mapping buried utilities, tanks, waste, and other underground anomalies before invasive investigations. Large scale surveys identify potential risks while small scale surveys characterize identified anomalies to better inform follow up actions.
Delineation of Hydrocarbon Bearing Reservoirs from Surface Seismic and Well L...IOSR Journals
Hydrocarbon reservoir has been delineated and their boundaries mapped using direct indicators from 3-D seismic and well log data from an oil field in Nembe creek, Niger Delta region. Well log signatures were employed to identify hydrocarbon bearing sands. Well to seismic correlation revealed that these reservoirs tied with direct hydrocarbon indicators on the seismic section. The results of the interpreted well logs revealed that the hydrocarbon interval in the area occurs between 6450ft to 6533ft for well A, 6449ft to 6537ft for well B and 6629ft to 6704ft for well C; which were delineated using the resistivity, water saturation and gamma ray logs. Cross plot analysis was carried out to validate the sensitivity of the rock attributes to reservoir saturation condition. Analysis of the extracted seismic attribute slices revealed HD5000 as hydrocarbon bearing reservoir.
The document discusses using science and technology to monitor land health through a global research project. It proposes establishing sentinel sites across Africa to collect soil samples and characterize properties using infrared spectroscopy and x-ray diffraction. These techniques can rapidly analyze soil organic carbon, minerals, and aggregate stability to provide reliable data on land functional properties and track changes over time.
This document evaluates the use of portable X-ray fluorescence (PXRF) spectrometry to measure soil salinity. 122 soil samples were collected from salt-impacted soils in Louisiana and analyzed using standard laboratory methods and PXRF. Standard analyses included particle size analysis, organic matter content, and electrical conductivity (EC) using a saturated paste. PXRF was used to quantify elemental concentrations. Simple and multiple linear regression models were developed to correlate elemental concentrations measured by PXRF (particularly Cl) to EC values. Both models produced acceptable correlations (R2 values of 0.83 and 0.90) between EC and PXRF data, though multiple regression using additional parameters like sand, clay and organic matter content was recommended
Anisotropic Avo Analysis for Reservoir Characterization in Derby Field Southe...IOSRJAP
Anisotropic AVO analysis for reservoir characterization in Derby field southeastern Niger delta has been investigated. The objective of this study was to investigate the AVO response of shale over gas sandsonisotropic and anisotropic synthetic models and the real CDP gathers. This was done by plotting amplitude of reflections versus offsets and carrying out AVO intercept-gradient analysison HD1horizon. The results of the models were compared with the real CDP gather to deduce the robust synthetic model for efficient AVO analysis in the field. Well, CDP processed gathers and Hampson-Russell GEOVIEW and AVO module were used for the analysis. Results revealed that the plots of amplitude versus offset of the isotropic and anisotropic synthetic models agree at near offset but show opposite AVO response due to increasing contributions of seismic anisotropy at far offsets. The results of the anisotropic synthetic model correlates well with the CDP gathers indicating that seismic anisotropy is an important factor in AVO analysis. Results also show that a bright spot indicative of gas charged sands was delineated for the isotropic and anisotropic models but with different classes of AVO anomalies andproducts. The isotropic synthetic model show a class II AVO anomaly with a positive AVO product, while the anisotropic model show a class IV AVO anomaly with a negative AVO product comparable to the real CDP gather.These analysesclearly show that description of rock without anisotropy especially, seismic anisotropy is incomplete since most rocks are not completely isotropic. Therefore, accounting for seismic anisotropy in AVO synthetic modelling will ensure that the correct earth model is predicted and the reservoir is adequately characterized.
12 reedlunn reinvestigation into closure predictions sand2016 8559leann_mays
Room D was an underground experiment at Waste Isolation Pilot Plant between 1984-1991 that measured rock salt creep around an excavated room. Early simulations underpredicted vertical closure of the room by 4.5x, requiring adjustments to model parameters. Recent interest in Room D has led to updating simulations using today's standards and recalibrating the constitutive model against new salt creep laboratory experiments. The updated model still underpredicts vertical closure, but by a reduced amount of 3.1x. Potential improvements to the model are discussed.
2D MASW ANALYSIS FOR GEOTECHNICAL ENGINEERINGAli Osman Öncel
This document describes a study that used seismic refraction and multi-channel analysis of surface waves (MASW) to investigate near-surface shear wave velocities at a site in Egypt. Seismic refraction was used to determine P-wave velocities down to depths of 30 m. MASW was used to determine 1D and 2D shear wave velocity profiles by analyzing Rayleigh surface wave dispersion. Shear wave velocities obtained from MASW were used to evaluate site response and classify the site according to standard site classifications. The study area consists of Quaternary deposits overlying Tertiary sedimentary rocks. P-wave and MASW surveys were conducted along multiple profiles using geophones and a seismograph to
This document describes a new prototype system for conducting MASW2D (Multichannel Analysis of Surface Waves 2D) surveys for roadside investigations. The system allows for continuous seismic profiling along roads with minimal traffic interruptions. It features a mobile land streamer towed slowly between recording stations, an accelerated weight source generating high seismic energy, and onboard data recording. Examples show how MASW2D has been used to assess geology and soil properties for underground construction projects in Istanbul and Milan, and to investigate slope failures from abandoned quarries. The system allows MASW2D to be efficiently applied in noisy urban environments.
A large-scale magnetic survey was conducted over 60,000 square meters in the archaeological area of Makrygialos, Greece. The survey aimed to map archaeological features before construction destroyed parts of the site. Magnetic anomalies revealed a system of three curvilinear ditches dating to the Neolithic period. Spectral analysis of magnetic data identified magnetic sources at depths of 0.35, 2.5, and 6.7 meters, correlating with archaeological evidence of ditches and disturbed soil layers. Geophysical prospecting effectively mapped a large portion of the site before its destruction, providing valuable information for future study.
Diffuse reflectance spectroscopy to estimate soil attributes of Brazilian wet...Agriculture Journal IJOEAR
Abstract— The study of soils and characterization of its attributes are continually evolving, however, for the condition of wetlands, such information is still scarce and poorly distributed. Thus, the objective of this work was to characterize spectrally the soils of a wetland area. On the study area were collected georeferenced soil samples and sent for chemical and physical analysis routine and then subjected to spectral evaluation. Were identified seven soil classes with hydromorphic characteristics in their spectral curves? The information contained in these curves then led the development of equations for soil attributes. Sand was the physical attribute of a better correlation with laboratory data and Cationic Exchange Capacity (CEC), the chemical attributes that showed better results.
Shear wave velocity and Geology Based Seismic Microzonation of Port-au-Prince...Johana Sharmin
This is a presentation entirely based on the paper published by Brady R. Cox and his team. I just focused on the key points of the paper in the presentation.
Multichannel analysis of surface waves Harish Parimi
Active and passive surface wave methods were used to image subsurface shear wave slowness at the Coyote Creek field site. Comparisons of slowness profiles from different methods showed generally good agreement, with most methods predicting larger near-surface slowness and smaller deep slowness compared to the reference model. Site amplification estimates based on the different slowness models were also generally similar. The blind interpretation experiment demonstrated that surface wave methods can provide robust shear wave velocity structures when multiple independent interpretations are considered.
This document summarizes a study that used airborne gamma spectrometry (radiometrics) data to map soils over large areas in Central Queensland, Australia in a more cost-effective way than traditional soil surveys. In a trial area of 6,000 ha, the study achieved 55.6% accuracy in predicting lithology, 65% for soil order, and 29% for soil profile class using radiometrics data and conceptual models. The models were refined and applied to a larger 49,000 ha area, achieving 63% accuracy for lithology prediction and soil order. Radiometrics was found to be useful for identifying broad soil characteristics and lithological units over large areas.
A statistical assessment of GDEM using LiDAR dataTomislav Hengl
This document presents a statistical assessment of the accuracy of the Global Digital Elevation Model (GDEM) using LiDAR data. It proposes a framework to evaluate GDEM accuracy by assessing absolute elevation errors, positional accuracy of hydrological features, surface roughness representation, and user satisfaction. Case studies in four areas show regression models can evaluate elevation fit, with an R-squared value above 0.995 indicating satisfactory accuracy for GDEM in areas of medium relief. The document concludes GDEM has little usefulness in areas of low relief.
This document discusses the use of non-invasive geophysical techniques to build 3D ground models and reduce the cost and risk of site investigations. It provides examples of using techniques like MASW, CSWS, GPR to map soil properties and depth to bedrock in order to develop detailed geotechnical models. Case studies describe creating models for a sewer project in Langat, Malaysia and a landfill project in Western Australia, allowing identification of problem areas without extensive drilling and reducing costs. The document concludes that geophysical techniques provide a cheap and quick way to gather valuable site information.
1. The document presents Victoria Naipal's PhD dissertation on modelling long-term sediment dynamics in an Earth System Model framework.
2. Naipal developed models to simulate soil erosion globally and sediment dynamics over the last millennium to quantify changes in sediment storage and fluxes.
3. The models were able to reproduce observed global patterns of soil erosion and sediment storage, and showed that land use change was the main driver of increased sediment storage over the last millennium.
Modelling Vegetation Patterns in Semiarid EnvironmentsSalvatore Manfreda
This document discusses modeling vegetation patterns in semi-arid environments. It presents a study of the Upper Rio Salado basin where a soil water balance model was coupled with patterns of vegetation, soil, and climate to generate spatial patterns of soil moisture and water stress. Different interaction rules for a cellular automata model were tested against observed vegetation patterns in the basin. The results showed that rules accounting for minimizing water stress and maximizing transpiration best replicated actual vegetation distributions. The model was then used to simulate changes in vegetation patterns and diversity under different rainfall scenarios by varying the mean rainfall rate and depth.
Soil properties and dune heath reestablishmentRhys Turton
This document summarizes soil analysis results from four trial plots on the Sefton Coast, England that are being used to study re-establishing heather habitat. Soil samples were collected and tested for pH, organic matter, magnetic susceptibility, exchangeable cations, nitrogen and phosphorus. The results show variation in properties between sites, with some having higher organic matter or exchangeable bases. However, there are no clear correlations between the soil analysis and the condition of the re-establishment techniques used at each site.
Field evaluation of a four component downholeoilandgas24
This document summarizes the field evaluation of a four-component downhole VLF-EM logging system. The system measures the axial electric field and three orthogonal magnetic field components of very low frequency electromagnetic signals transmitted from stations. Field tests were conducted at six sites in Ontario and New Brunswick representing different geological conditions. Results demonstrate the potential of downhole VLF-EM for mineral exploration and structural mapping. An example from the Stratmat massive sulphide deposit shows dramatic changes in the magnetic fields across ore zones, clearly delineating them, while the electric field response was more difficult to interpret with the 10m electrode spacing.
The document summarizes research on modeling and analyzing soil moisture patterns at the basin scale using ground-based field data and remote sensing results. Key findings include:
1) For wet conditions, soil moisture variance increases with spatial scale following a power law, while for dry conditions variance is spatially uniform and independent of scale.
2) Soil moisture variance and correlation length depend on basin wetness. Spatial correlation follows a power law decay up to 1 km and exhibits multiscaling at larger scales.
3) Modeling results using GEOtop agree with remote sensing results from ESTAR in characterizing soil moisture variability and correlation.
Contributions of Satellite Images in the Diachronic Study of the Stanley-Pool...INFOGAIN PUBLICATION
With increased population now days, there is a marked change in morphology of the land when it comes the analysis of space images (satellite) using remote sensing. This study covers a sample application of the use of spatial imagery for mapping land cover in the Stanley-Pool (Congo - Brazzaville). The approach used here is based on confrontation of satellite data acquired on different dates (2001-2005). These images were chosen because of realization a demographic growth during this period. The results of this study show a great advance in land occupation which affected the whole of the autonomous port of Brazzaville.
EphGEE is a tool for estimating ephemeral gully erosion. It uses the CREAMS conceptual model to simulate gully evolution through a two-phase process of downcutting and widening. Soil erodibility and critical shear stress are estimated based on soil properties. Sediment transport is modeled using a finite volume mass balance approach. EphGEE was tested on a 6.3 hectare watershed in Iowa over 17 years and showed it could estimate sediment yields with and without a grassed waterway more accurately than RUSLE2 alone. The program is being developed as a web-based tool to help estimate ephemeral gully erosion.
This document compares methods for determining subsurface shear-wave velocity, which is important for seismic hazard assessment. It analyzes data from seismic cone penetration tests (SCPT), spectral analysis of surface waves (SASW), continuous surface wave system (CSWS), and microtremors in the Victoria, Canada area. The peak frequencies determined from SCPT measurements generally agree well with microtremor measurements, as both sample to similar depths. Surface wave methods like SASW and CSWS have more limited depth penetration and thus microtremor frequencies are sometimes lower. Combining microtremors with invasive or active non-invasive methods provides the best characterization of site response.
This document provides an overview of a publication containing papers from the Symposium on Geophysical Methods for Geotechnical Investigations. The publication covers both surface and borehole geophysical techniques applied to environmental and geotechnical engineering problems. Surface methods provide horizontal maps or vertical profiles of subsurface properties, while borehole methods provide continuous vertical logs of properties along boreholes. Together, surface and borehole methods provide complementary data for characterizing geological formations and groundwater.
This paper describes a comprehensive seismic microzonation investigation carried out for the North-West New Territories region of Hong Kong. Over 3000 boreholes and in-situ and laboratory tests were used to characterize soil properties and develop shear wave velocity profiles for the area. One-dimensional site response analyses were performed on 27 soil profiles to determine how the soils would respond to different levels of earthquake ground motions. The results were used to classify the sites into four groups based on their period and develop corresponding design response spectra. Microzonation maps showing variations in average shear wave velocity and natural period in the study area were generated to delineate differences in seismic hazards spatially.
Archaeological and groundwater investigationsZaidoon Taha
This document discusses the use of seismic methods for archaeological and groundwater investigations. It provides examples of how seismic reflection and refraction surveys can be used to map subsurface structures and locate buried archaeological remains or water sources. Specifically, it describes 3D seismic acquisition techniques that provide ultra-high resolution for shallow investigations. Case studies demonstrate how seismic imaging can detect a buried shipwreck and Roman dyke. The document also discusses applications of seismic methods for groundwater exploration, such as locating aquifers and fractured zones.
This document describes a new prototype system for conducting MASW2D (Multichannel Analysis of Surface Waves 2D) surveys for roadside investigations. The system allows for continuous seismic profiling along roads with minimal traffic interruptions. It features a mobile land streamer towed slowly between recording stations, an accelerated weight source generating high seismic energy, and onboard data recording. Examples show how MASW2D has been used to assess geology and soil properties for underground construction projects in Istanbul and Milan, and to investigate slope failures from abandoned quarries. The system allows MASW2D to be efficiently applied in noisy urban environments.
A large-scale magnetic survey was conducted over 60,000 square meters in the archaeological area of Makrygialos, Greece. The survey aimed to map archaeological features before construction destroyed parts of the site. Magnetic anomalies revealed a system of three curvilinear ditches dating to the Neolithic period. Spectral analysis of magnetic data identified magnetic sources at depths of 0.35, 2.5, and 6.7 meters, correlating with archaeological evidence of ditches and disturbed soil layers. Geophysical prospecting effectively mapped a large portion of the site before its destruction, providing valuable information for future study.
Diffuse reflectance spectroscopy to estimate soil attributes of Brazilian wet...Agriculture Journal IJOEAR
Abstract— The study of soils and characterization of its attributes are continually evolving, however, for the condition of wetlands, such information is still scarce and poorly distributed. Thus, the objective of this work was to characterize spectrally the soils of a wetland area. On the study area were collected georeferenced soil samples and sent for chemical and physical analysis routine and then subjected to spectral evaluation. Were identified seven soil classes with hydromorphic characteristics in their spectral curves? The information contained in these curves then led the development of equations for soil attributes. Sand was the physical attribute of a better correlation with laboratory data and Cationic Exchange Capacity (CEC), the chemical attributes that showed better results.
Shear wave velocity and Geology Based Seismic Microzonation of Port-au-Prince...Johana Sharmin
This is a presentation entirely based on the paper published by Brady R. Cox and his team. I just focused on the key points of the paper in the presentation.
Multichannel analysis of surface waves Harish Parimi
Active and passive surface wave methods were used to image subsurface shear wave slowness at the Coyote Creek field site. Comparisons of slowness profiles from different methods showed generally good agreement, with most methods predicting larger near-surface slowness and smaller deep slowness compared to the reference model. Site amplification estimates based on the different slowness models were also generally similar. The blind interpretation experiment demonstrated that surface wave methods can provide robust shear wave velocity structures when multiple independent interpretations are considered.
This document summarizes a study that used airborne gamma spectrometry (radiometrics) data to map soils over large areas in Central Queensland, Australia in a more cost-effective way than traditional soil surveys. In a trial area of 6,000 ha, the study achieved 55.6% accuracy in predicting lithology, 65% for soil order, and 29% for soil profile class using radiometrics data and conceptual models. The models were refined and applied to a larger 49,000 ha area, achieving 63% accuracy for lithology prediction and soil order. Radiometrics was found to be useful for identifying broad soil characteristics and lithological units over large areas.
A statistical assessment of GDEM using LiDAR dataTomislav Hengl
This document presents a statistical assessment of the accuracy of the Global Digital Elevation Model (GDEM) using LiDAR data. It proposes a framework to evaluate GDEM accuracy by assessing absolute elevation errors, positional accuracy of hydrological features, surface roughness representation, and user satisfaction. Case studies in four areas show regression models can evaluate elevation fit, with an R-squared value above 0.995 indicating satisfactory accuracy for GDEM in areas of medium relief. The document concludes GDEM has little usefulness in areas of low relief.
This document discusses the use of non-invasive geophysical techniques to build 3D ground models and reduce the cost and risk of site investigations. It provides examples of using techniques like MASW, CSWS, GPR to map soil properties and depth to bedrock in order to develop detailed geotechnical models. Case studies describe creating models for a sewer project in Langat, Malaysia and a landfill project in Western Australia, allowing identification of problem areas without extensive drilling and reducing costs. The document concludes that geophysical techniques provide a cheap and quick way to gather valuable site information.
1. The document presents Victoria Naipal's PhD dissertation on modelling long-term sediment dynamics in an Earth System Model framework.
2. Naipal developed models to simulate soil erosion globally and sediment dynamics over the last millennium to quantify changes in sediment storage and fluxes.
3. The models were able to reproduce observed global patterns of soil erosion and sediment storage, and showed that land use change was the main driver of increased sediment storage over the last millennium.
Modelling Vegetation Patterns in Semiarid EnvironmentsSalvatore Manfreda
This document discusses modeling vegetation patterns in semi-arid environments. It presents a study of the Upper Rio Salado basin where a soil water balance model was coupled with patterns of vegetation, soil, and climate to generate spatial patterns of soil moisture and water stress. Different interaction rules for a cellular automata model were tested against observed vegetation patterns in the basin. The results showed that rules accounting for minimizing water stress and maximizing transpiration best replicated actual vegetation distributions. The model was then used to simulate changes in vegetation patterns and diversity under different rainfall scenarios by varying the mean rainfall rate and depth.
Soil properties and dune heath reestablishmentRhys Turton
This document summarizes soil analysis results from four trial plots on the Sefton Coast, England that are being used to study re-establishing heather habitat. Soil samples were collected and tested for pH, organic matter, magnetic susceptibility, exchangeable cations, nitrogen and phosphorus. The results show variation in properties between sites, with some having higher organic matter or exchangeable bases. However, there are no clear correlations between the soil analysis and the condition of the re-establishment techniques used at each site.
Field evaluation of a four component downholeoilandgas24
This document summarizes the field evaluation of a four-component downhole VLF-EM logging system. The system measures the axial electric field and three orthogonal magnetic field components of very low frequency electromagnetic signals transmitted from stations. Field tests were conducted at six sites in Ontario and New Brunswick representing different geological conditions. Results demonstrate the potential of downhole VLF-EM for mineral exploration and structural mapping. An example from the Stratmat massive sulphide deposit shows dramatic changes in the magnetic fields across ore zones, clearly delineating them, while the electric field response was more difficult to interpret with the 10m electrode spacing.
The document summarizes research on modeling and analyzing soil moisture patterns at the basin scale using ground-based field data and remote sensing results. Key findings include:
1) For wet conditions, soil moisture variance increases with spatial scale following a power law, while for dry conditions variance is spatially uniform and independent of scale.
2) Soil moisture variance and correlation length depend on basin wetness. Spatial correlation follows a power law decay up to 1 km and exhibits multiscaling at larger scales.
3) Modeling results using GEOtop agree with remote sensing results from ESTAR in characterizing soil moisture variability and correlation.
Contributions of Satellite Images in the Diachronic Study of the Stanley-Pool...INFOGAIN PUBLICATION
With increased population now days, there is a marked change in morphology of the land when it comes the analysis of space images (satellite) using remote sensing. This study covers a sample application of the use of spatial imagery for mapping land cover in the Stanley-Pool (Congo - Brazzaville). The approach used here is based on confrontation of satellite data acquired on different dates (2001-2005). These images were chosen because of realization a demographic growth during this period. The results of this study show a great advance in land occupation which affected the whole of the autonomous port of Brazzaville.
EphGEE is a tool for estimating ephemeral gully erosion. It uses the CREAMS conceptual model to simulate gully evolution through a two-phase process of downcutting and widening. Soil erodibility and critical shear stress are estimated based on soil properties. Sediment transport is modeled using a finite volume mass balance approach. EphGEE was tested on a 6.3 hectare watershed in Iowa over 17 years and showed it could estimate sediment yields with and without a grassed waterway more accurately than RUSLE2 alone. The program is being developed as a web-based tool to help estimate ephemeral gully erosion.
This document compares methods for determining subsurface shear-wave velocity, which is important for seismic hazard assessment. It analyzes data from seismic cone penetration tests (SCPT), spectral analysis of surface waves (SASW), continuous surface wave system (CSWS), and microtremors in the Victoria, Canada area. The peak frequencies determined from SCPT measurements generally agree well with microtremor measurements, as both sample to similar depths. Surface wave methods like SASW and CSWS have more limited depth penetration and thus microtremor frequencies are sometimes lower. Combining microtremors with invasive or active non-invasive methods provides the best characterization of site response.
This document provides an overview of a publication containing papers from the Symposium on Geophysical Methods for Geotechnical Investigations. The publication covers both surface and borehole geophysical techniques applied to environmental and geotechnical engineering problems. Surface methods provide horizontal maps or vertical profiles of subsurface properties, while borehole methods provide continuous vertical logs of properties along boreholes. Together, surface and borehole methods provide complementary data for characterizing geological formations and groundwater.
This paper describes a comprehensive seismic microzonation investigation carried out for the North-West New Territories region of Hong Kong. Over 3000 boreholes and in-situ and laboratory tests were used to characterize soil properties and develop shear wave velocity profiles for the area. One-dimensional site response analyses were performed on 27 soil profiles to determine how the soils would respond to different levels of earthquake ground motions. The results were used to classify the sites into four groups based on their period and develop corresponding design response spectra. Microzonation maps showing variations in average shear wave velocity and natural period in the study area were generated to delineate differences in seismic hazards spatially.
Archaeological and groundwater investigationsZaidoon Taha
This document discusses the use of seismic methods for archaeological and groundwater investigations. It provides examples of how seismic reflection and refraction surveys can be used to map subsurface structures and locate buried archaeological remains or water sources. Specifically, it describes 3D seismic acquisition techniques that provide ultra-high resolution for shallow investigations. Case studies demonstrate how seismic imaging can detect a buried shipwreck and Roman dyke. The document also discusses applications of seismic methods for groundwater exploration, such as locating aquifers and fractured zones.
This document describes how multichannel analysis of surface waves (MASW) was used to map variations in bedrock and detect potential fractures at a site in Olathe, Kansas where industrial contaminants may have leaked. MASW data was acquired along linear profiles using standard seismic acquisition techniques. Analysis of surface wave dispersion characteristics generated a 2D shear wave velocity model that accurately mapped the bedrock surface between 6-23 feet deep and identified potential fracture zones in the bedrock. The high resolution shear wave velocity model provided essential information for characterizing subsurface fluid flow at the contaminated site.
Many seismic sources have been developed to satisfy conflicting demands of resolution, penetration, repeatability, efficiency and cost. The Betsy seismic shotgun was developed in the late 1970s as a portable, inexpensive source for shallow reflection or refraction surveys. Field tests of the shotgun near Mymam, Alberta evaluated penetration depth, effects of acquisition parameters, and environmental effects on quality. Useful reflection data was obtained between 3-7 seconds subsurface (300-700m), with reflections at 1 second and refracted arrivals visible to 600m offsets under good conditions. Record quality depended on soil conditions, with energy coupling inversely related to soil rigidity and wind degrading quality.
This document summarizes two field studies that used time domain electromagnetics (TEM) to investigate subsurface water in Mars analog environments. A TEM survey in Arizona was able to image around 500 meters depth and locate groundwater around 120 meters deep, consistent with well data. A separate fast-turnoff TEM survey in Spain imaged around 200 meters depth with a conductive layer at 90 meters interpreted as the water table. Both studies demonstrate TEM is suitable for probing deep groundwater relevant to Mars.
This document introduces a special section on advances in time-lapse geophysics. It summarizes that time-lapse geophysics is an important method for monitoring complex subsurface processes over time, with applications in resource management, geohazards, environmental issues, and more. Recent innovations allow for improved 4D signal detection, more frequent/continuous monitoring, and extraction of more detailed subsurface information in near real-time. The special section aims to present state-of-the-art technical articles on time-lapse geophysics across applications, theories, data acquisition, and analysis to convey new developments and stimulate further research.
1) High-resolution seismic methods were used to map the detailed structure and thickness of coal seams in the Domeniko coal basin in Greece. 2) Reflection events attributed to coal layers could be interpreted from depths of 30-150 meters on processed seismic sections. 3) Several low-throw faults were also interpreted from the sections. 4) When combined with drillhole data using geostatistical methods, the seismic survey results clearly revealed the 3D model of the coal basin.
High-Resolution 3D Seismic: Coal Mines FieldsAli Osman Öncel
1. CONSOL developed a robust coal geophysics program between 1985-2000 that utilized various seismic and non-seismic methods to address exploration, engineering, and environmental challenges.
2. A key case study involved using high-resolution 3D surface seismic data to detect a complex geologic anomaly called a "roll" in a coal seam, which showed up as amplitude anomalies.
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2. 82 SHALLOW SEISMIC IN URBAN AREAS
INTRODUCTION
Since the 1990s in great Brazilian urban centres, an expressive in-
crease of civil works focused in infrastructure needs is happening,
and, following a worldwide tendency, they have been concentrated
in underground infrastructure and facilities such as road tunnels,
overflow retention reservoirs, pipelines, power lines, etc.
Aiming at elaborating design-build projects and executing the
previously mentioned works a good geological knowledge is ne-
cessary such as spatial distribution of geological strata and thick-
nesses, as well as recognition and positioning of geological struc-
tures.
In this context, shallow seismic reflection presents a great
application potential, once it allows mapping structures continu-
ously, interpolating subsurface geological information obtained
from drilling at discrete locations (Hunter et al., 1984; Jeng, 1995;
Steeples & Miller, 1990).
However, urban environment presents several aspects that
damage or hamper the acquisition as well as the analysis of
seismic data, as restricted operation space and altered superfi-
cial strata (earth embankments and asphaltic coverage), likewise
background noise associated to power lines and shake noise from
the traffic.
Those factors are contributed so that seismic reflection does
not be considered yet an effective investigative method for buil-
ding practitioners in Brazilian urban centres. (Prado et al., 2001).
In order to investigate the accuracy and potentiality of shal-
low seismic reflection method in the described conditions, seve-
ral pseudo walkaway noise tests were accomplished in a densely
occupied area of S˜ao Paulo city. Another assay was also accom-
plished as comparative tests in controlled laboratory conditions
for evaluating the spectral content of seismic signal by using clay
in geophone coupling.
Results of acquisition, carried out with different types of geo-
phones and sources, as well coupling conditions are presented.
We discuss the results of comparative tests among geopho-
nes of different frequencies and plant in soils and on asphaltic
coverage through spikes and clay. Geophone responses obtained
from tests in shake table are also discussed.
LOCATION AND GEOLOGICAL CONTEXT OF STUDY AREA
The study area is located in Western S˜ao Paulo city, in the left
margin of Pinheiros River (Figure 1). The choice of this place was
conditioned by several factors: i) existence of geological infor-
mation from nearby boreholes; ii) possibility to do simultaneous
acquisition on asphaltic coverage and soil; iii) to be placed in a
typical urban space, with heavy traffic of vehicles and people.
The geology of this area consists of tertiary sediments of
Itaquaquecetuba Formation from S˜ao Paulo Sedimentary Basin,
which settles on Precambrian basement. PP1 well description lo-
cated closetheacquisition areaprovidesthefollowing information
about main lithofacies: (1) sands until 25 m depth; (2) conglome-
rate from 25 m to 35m; (3) sands from 35 m to 52 m; (4) clays
from 52 m to 80 m; (5) granite-gneisse basement.
METHODOLOGY
Initially, 1D geological model was obtained, analysing information
from PP1 well (Figure 2a); synthetic seismograms were generated
from this model by using Triseis algorithm of Seismic Unix soft-
ware (Stockwell & Cohen, 1998) in order to estimate the reflection
travel time from the interfaces (Figure 2b).
Following, several pseudo walkaway tests were executed. The
tests were made using 28 Hz and 100 Hz geophones, both coupled
to soil with spikes of 0.1 m and 0.18 m length, and fixed with clay
in paved area (Figures 3a, 3b). On soil, two types of sources were
used: (1) 12-caliber rifle (Figure 3d), fired in holes of approxima-
tely 0.4 m deep; (2) sledge hammer of 6 Kg (Figure 3c) impacted
on steel plate. Hammer was used on pavement with impacts on
plate and directly on asphalt. Table 1 presents parameters and
geometry employed in these tests.
Table 1 – Pseudo walkaway tests acquisition parameters.
Number of chanels 24
Minimum offset 0,5 m
Maximum offset 72 m
Receiver spacing 0,5
Geophone type 28 Hz and 100 Hz
Source type 12-caliber rifle and Sledgehammer - 6 Kg
Coupling Spike (0,10 m and 0,18 m), Kaolinitic clay
Sample rate 0,25 ms
Recording time 200 ms
Pre A/D low cut filter 3 Hz
The main objective of these field tests was to compare res-
ponsesofdifferentgeophones, indifferentcouplingsituationsand
with wave generation of several seismic sources, and starting from
this study finding to establish equipment and ideal parameters to
improve the quality and resolution of shallow seismic reflection.
The comparative study was based on the analysis of ampli-
tude spectra obtained by different test conditions, as well as on
final results of seismogram processing.
Since these first results, a second field test was carried out
aiming at checking previous results in a more controlled envi-
Revista Brasileira de Geof´ısica, Vol. 24(1), 2006
3. OLEG BHOKONOK, RENATO LUIZ PRADO and LILIANA ALCAZAR DIOGO 83
Figure 1 – Site map showing seismic test line, wells and local geology (adapted from Iritani, 1993).
ronment in which geophone parameters (frequency and coupling)
were tested simultaneously by the same energy generation. For
that, a walkaway test was made with five parallel linear arrays, with
0.4 m equidistant one each other, and 4 geophones each one (1 m
spacing). All arrays were connected to the same seismic cable and
acquisition system. New records were acquired with variations of
sources, geophones and coupling, concurrently, with minimum
offsets of 20, 40 and 60 meters (Figure 4).
Besides field tests, tests with geophones were also done un-
der controlled laboratory conditions, in order to evaluate their res-
ponses using different clay mineral for coupling.
The experiment (Figure 5) was constituted by APS Dynamics
Inc shake table (APS Electro-six model) positioned at a mas-
sive block of concrete, Entelbra audio generator (ETB511 model),
APS Dynamics Inc Power Amplifier signal amplifier (124 mo-
del), OYO seismograph (DAS-1 model), Tectronix oscilloscope
(TDS220 model), four 100 Hz geophones, and three different clay
samples (Table 2). A tray, specifically projected for this experi-
ment, was fixed to shake table. This tray allowed fixing rigidly one
of the four geophones, along with reproducing a similar surface
of paved area via small rugosities (Figure 6).
Laboratory tests were executed as following: i) firstly, 4 geo-
phones were rigidly fixed to the table, and simultaneously submit-
ted to the same shake signal to attest the equivalence among their
responses (Figure 6a); ii) subsequently one of them was used as
reference for an ideal coupling (rigidly fixed to the table), and the
other ones coupled with three different clay samples (Table 2).
02-geophone was coupled by using 01-Sample; 03-geophone
by using 02-Sample; and 04-geophone, 03-Sample (Figure 6b);
iii) The shake table was submitted to a sinusoidal excitation with
a frequency bandwidth from 80 Hz up to 120 Hz (in 5 Hz steps),
characteristic of shallow seismic field test previously got done;
Brazilian Journal of Geophysics, Vol. 24(1), 2006
4. 84 SHALLOW SEISMIC IN URBAN AREAS
Figure 2 – (a) Geological model generated from PP1 log; (b) synthetic seismogram generated from the geological model.
Event 1: interface soil/water table, 5 m of depth, Vint = 0.4 km/s (interval velocity); event 2: top of conglomerate, 25 m of
depth, Vint = 1.7 km/s; event 3: top of clay, 52 m of depth, Vint = 2.1 km/s; event 4: basement, 80 m of depth, Vint = 2.4 km/s.
iv) simultaneous records were made with oscilloscope and seis-
mograph.
The same clay samples were submitted to mineralogical
analysis by X-Ray difratometry (Table 2). Results indicated the
clay from 01-Sample was predominantly kaolinitic (90-95%) dif-
ferently to the two other ones that contained a considerable
amount of smectite and illite (up to 55%).
Table 2 – Mineralogical Analysis of clay samples originated from
X rays difratometry.
Sample Clay mineral Semiquantification (%)
Kaolinite 90 – 95
Sample 01 Illite 3 – 5
Smectite < 2
Kaolinite 50
Sample 02 Smectite 35 – 40
Illite 10 – 15
Kaolinite 60 – 65
Sample 03 Illite 20 – 25
Smectite < 15
An analysis was also made to establish the moisture content
of these samples. The moisture content was determined as the
rate between water weight and dry solid material weight expres-
sed in percentage. Results are presented in Table 3. It is possi-
ble to observe the found contents were relatively similar, although
the largest value (24%) was associated to more kaolinitic sample
(01-Sample).
Table 3 – Moisture content of clay samples.
Sample Moisture content (%)
Sample 01 24,64
Sample 02 19,25
Sample 03 23,30
RESULTS
After the acquisition of first in situ data, the initial processing had
as objective to identify the reflections in the seismograms and to
compare them with synthetic seismograms generated since infor-
mation from PP1 well.
Revista Brasileira de Geof´ısica, Vol. 24(1), 2006
5. OLEG BHOKONOK, RENATO LUIZ PRADO and LILIANA ALCAZAR DIOGO 85
Figure 3 – (a) Geophones with spikes of 0.1m and 0.18m (b) geophones coupled through clay; (c) sledge hammer of 6 Kg; (d) 12’ seismic rifle.
Figure 4 – Outline illustrating the type of array used in the second comparative field test: (a) 100 Hz geophones
coupled through clay; (b) 100 Hz geophones with spike of 0.18 m; (c) 100 Hz geophones with spike of 0.1 m;
(d) 28 Hz geophones with spike of 0.18 m; (e) 28 Hz geophones with spike of 0.1m.
Brazilian Journal of Geophysics, Vol. 24(1), 2006
6. 86 SHALLOW SEISMIC IN URBAN AREAS
Figure 5 – Design of shake table test: (a) APS Dynamics Inc. shake table (APS Electro-six model); (b) massive block of
concrete; (c) Entelbra audio generator (ETB511 Model); (d) APS Dynamics Inc. Power Amplifier signal amplifier (124 model);
(e) OYO-1 seismograph; (f) Tectronix oscilloscope (TDS220 Model); (g) four 100 Hz geophones; (h) geophone “tray”.
Figure 6 – (a) Geophone rigidly fixed to table and submitted to shake signal; (b) 01-geophone used as reference of an
ideal coupling (rigidly fixed to the table), and the other ones coupled with 3 different clay samples. 02-geophone coupled
by using 01-Sample, 03-geophone by using 02-Sample, and 04-geophone by using 03-Sample.
Processing challenge was to preserve the high frequency con-
tents and to enhance shallow reflections from “noisy” events such
as direct wave, refractions, ground roll, and airwave.
Initially passband frequency filters were applied. Several
bandwidth and different slopes were tested, with no satisfactory
results to an increase in signal/ noise ratio.
F-k filter was applied in order to eliminate events associated
to ground roll and airwave, taking care to extend the fan reject zone
to spectrum part associated to spatial aliasing of airwave.
Finally, applying an AGC gain, final seismogram was obtai-
ned, presenting three evident reflection events in 50 milliseconds,
relative to the top of conglomerate; 75 ms, associated to the top
of clay; and 100 ms, related to the basement (Figure 7).
Figure 8 presents responses of four geophones that were fi-
xed to the shake table and simultaneously submitted to an input
signal programmed by audio generator. As suggested by data, all
responses are equivalent. It can be also observed in Figure 8b –
generated from oscilloscope measurements – and in Figure 8c –
generated from traces recorded in seismograph – 01-geophone,
with ideal coupling, has a frequency distribution similar to three
geophones coupled to different clays. However, the record ob-
tained with 02-geophone (red line), coupled predominantly with
kaolinitic clay (01-Sample), presents a decrease of energy.
CONCLUSIONS
Comparative analysis of all seismograms from walkaway tests
after processing, showed the best results were obtained with:
Revista Brasileira de Geof´ısica, Vol. 24(1), 2006
7. OLEG BHOKONOK, RENATO LUIZ PRADO and LILIANA ALCAZAR DIOGO 87
Figure 7 – (a) Seismogram recorded with 100 Hz geophones coupled through spikes of 0.18 m on soil by using
sledge hammer impacted on steel plate; (b) record obtained with 100 Hz geophones coupled through clay on asphal-
tic pavement by using hammer impacted on steel plate. The events interpreted starting from the analysis of synthetic
seismogram generated since the description of PP1 well (Figure 2). Event 2: top of conglomerate, 25 m of depth, Vint
= 1.7 km/s; event 3: top of clay, 52 m of depth, Vint = 2.1 km/s; event 4: basement, 90 m of depth, Vint = 2.4 km/s.
(i) 100 Hz geophones with spike of 0.18 m, and hammer source
with steel plate; (ii) 100 Hz geophones coupled through clay on
asphaltic coverage with hammer source applied on asphalt.
Analyses of amplitude spectra for the second field experiment
indicated: (1) increase of length spike (from 0.10 m to 0.18 m)
did not improve the signal/ noise ratio (Figure 9a); (2) 100 Hz
geophones coupled through clay on pavement achieved an equi-
valent result to geophones coupled with spikes on soil, since
their amplitude spectra were analogous (Figure 9c); (3) 100 Hz
geophone had its higher energy response in band of frequen-
cies from 30 Hz up to 120 Hz, differently to 28 Hz geophone that
showed an accentuated fall in its spectrum of approximately 20 db
between predominant frequency (∼20 Hz), and the highest fre-
quencies (> 60 Hz), which explains the worst quality of acquired
data by using 28 Hz geophones (Figure 9b); (4) results obtained
with hammer applied on pavement and in plate on pavement were
equivalent to those ones obtained with hammer applied in plate
on soil (Figure 9c); (5) data obtained from laboratory tests sug-
gest that clay is a good alternative to couple geophones, notwiths-
tanding kaolinitic clays are not the most appropriate. According
to Souza-Santos (1989) clay mineral from kaolinitic group with
30-60% of moisture content passes to liquid state (liquidity li-
mit), differently, for example, of clay mineral of smectite group
that remains in plastic state even when moisture content is near
or higher than 60%. It can be conclude although the three sam-
ples (particularly 01-Sample and 03-Sample) have presented si-
milar moisture content (Table 3), predominantly kaolinitic clay
(90-95% – 01-Sample) had an inferior performance (larger at-
tenuation of induced energy) at the moment of the tests due to its
mechanical properties. Obviously, it is necessary to observe other
samples with different clay mineral contents in order to obtain an
embracing conclusion.
Brazilian Journal of Geophysics, Vol. 24(1), 2006
8. 88 SHALLOW SEISMIC IN URBAN AREAS
Figure 8 – Spectra obtained from records in comparative experimental tests in laboratory: a) responses of 01, 02, 03, 04-
geophones rigidly fixed to table, and simultaneously submitted to the same shake signal; b) responses of 02, 03, 04-geophones
coupled through clay, and of 01-geophone with ideal coupling measured directly in oscilloscope; c) responses of 02, 03, 04-
geophones coupled through clay, and of 01-geophone with ideal coupling recorded in seismograph.
Figure 9 – Spectra of field records obtained with different types of geophones, sources and coupling conditions: (a) 100 Hz geophones with spike of 0.18
m and 0.1 m, sledge hammer source; (b) 100 Hz (10 impacts) and 28Hz (1 impact) geophones, hammer impacted on steel plate; (c) 100 Hz geophones
coupled with spike of 0.18 m, and hammer impacted on steel plate (blue), and coupled through clay on pavement with impact directly on pavement (green),
and on steel plate (red).
Revista Brasileira de Geof´ısica, Vol. 24(1), 2006
9. OLEG BHOKONOK, RENATO LUIZ PRADO and LILIANA ALCAZAR DIOGO 89
ACKNOWLEDGMENTS
The authors would like to thanks CNPq (Conselho Nacional de
Pesquisa, Brasil). We are also grateful for comments from two
anonymous reviewers that helped clarify the manuscript.
REFERENCES
HUNTER JA, PULLAN SE, BURNS RA, GAGNE RM & GOOD RL. 1984.
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IRITANI MA. 1993. Potencial Hidrogeol´ogico da Cidade Universit´aria de
S˜ao Paulo. S˜ao Paulo, SP. 97 p. Dissertac¸˜ao de Mestrado (Geociˆencias).
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JENG Y. 1995. Shallow seismic investigation of a site with poor reflection
quality. Geophysics, 60: 1725–1726.
PRADO RL, MALAGUTTI FILHO W & DOURADO JC. 2001. The use of
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sites: an evaluation in the city of S˜ao Paulo, Brasil. Brazilian Journal of
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STOCKWELL JW & COHEN JK. 1998. The New SU (Seismic Unix) User’s
Manual. CWP – Colorado School of Mines, USA, version 2.2.
STEEPLES DW & MILLER RD. 1990. Seismic reflection methods applied
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Tutorial: Soc. Expl. Geophys., 1–30.
SOUZA-SANTOS P. 1989. Ciˆencia e tecnologia de argilas. S˜ao Paulo,
EDUSP, 1089 pp.
NOTES ABOUT THE AUTHORS
Oleg Bhokonok. He obtained his B.Sc in Geology from Kharkiv National University, Ukraine (1999) and his MSc in Geophysics from S˜ao Paulo University, IAG/USP,
Brazil, 2005. Currently he is working at Grant Geophysical Int. His current interests include seismic methods (processing and acquisition).
Renato Luiz Prado. He obtained his B.Sc in Geology from S˜ao Paulo University, USP, Brazil (1982), his MSc in Geophysics (IAG/USP, 1994) and Ph.D. in Geosciences
and Environment from S˜ao Paulo State University, UNESP (2001). From 1982 to 2001 he was employed as Researcher at Institute for Technological Researches, IPT,
Brazil. In 2001, he joined the faculty at geophysical department of S˜ao Paulo University. His primary research interests include seismic methods and GPR.
Liliana Alcazar Diogo. She obtained her B.Sc in Geophysics from S˜ao Paulo University, USP, Brazil (1989) and her Ph.D. in Geophysics from Federal University
of Bahia (UFBA, 1995). Since 1997 she is professor at the geophysical department of USP. Her current research interests include seismic processing, imaging and
inversion.
Brazilian Journal of Geophysics, Vol. 24(1), 2006