Earthquake detection using P and S waves, IEEE Conference


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Project to detect the earthquake using primary and secondary waves.

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Earthquake detection using P and S waves, IEEE Conference

  1. 1. Analysis of Magnitude for Earthquake Detection using Primary waves and Secondary waves VARDHAMAN COLLEGE OF ENGINEERING (AUTONOMOUS) Shamshabad – 501 218, Hyderabad. Presented by Shankar Murthy P ICHCI’13
  2. 2. Abstract Introduction Tectonic plates Earthquake Existing system Proposed system Experimentation Methodology Conclusions Future Enhancements Presentation Flow ICHCI’13
  3. 3. Abstract Earthquake is the natural disaster which occurs due to release of sudden energy. It occurs due to imbalance in stress field and strength field. Certain waves are released during earthquake, called Seismic waves, which are recorded over seismogram to calculate its intensity on Richter magnitude scale. Many methods like Precursor techniques, Animal behavior have been propose to detect/predict the earthquake. A new technique based on seismic waves is proposed to determine earthquake magnitude and few seismic parameters. ICHCI’13
  4. 4. Introduction Earth  It is also called as “Blue planet”, as it supports life existence.  It has four spheres namely Biosphere, Lithosphere, Hydrosphere, Atmosphere. Formation of earth  Many theories have been proposed to support this formation like Steady state theory, Cyclic Universe theory among all these, Big Bang theory is the Universal accepted theory.  Earth got cooled down due to continuous loss of heat energy which resulted in formation of several layers. ICHCI’13
  5. 5. Layers of earth 1. Crust 2. Upper mantle 3. Transition 4. Lower mantle 5. D’’ layer 6. Outer core 7. Inner core Liquid rocky materials ICHCI’13
  6. 6. Tectonic Plates Tectonic plates are puzzle like structures which floats above the liquid rocky materials in the outer core. The shaking of these tectonic plates results in shaking of earth surface, known as earthquake. There are eight major and many minor tectonic plates. Convergent, Divergent and Transform are the types of tectonic movements. ICHCI’13
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  8. 8. Year Disaster Location 1931 Flood China 1887 Flood China 1556 Earthquake China 1970 Cyclone Bangladesh 2010 Earthquake Haiti 1926 Earthquake Antioch 1976 Earthquake China 2004 Tsunami Indian Ocean 1920 Earthquake Haiyuan 1975 Dam Failure China ICHCI’13
  9. 9. Earthquake Earthquake is the sudden release of energy, which results due to imbalance between strength field of tectonic plates and stress field of heat energy released from molten liquid in outer core. The location within the earth where the rock breaks is called Origin and the location on earth surface straight above the focus is called as Epicenter. ICHCI’13
  10. 10. The waves originate from focus are Primary waves (P-waves) and Secondary waves (S-waves). Love waves, Stonely waves, Rayleigh waves originate from Epicenter. The speed of P-waves is 4800 meters/sec and speed of S-waves is 3400 meters/sec. ICHCI’13
  11. 11. Existing System Many different techniques have been proposed to detect the earthquake. 1. Animal Behavior 2. Precursors 3. Co-seismic signal extractions 4. Early Earthquake Warning systems (EEWS) These experimentation determined the occurrence of earthquake and alerts by issuing the alarm. ICHCI’13
  12. 12. Animal Behavior • Chinese conducted an experiment over animals like snakes and rats. • The unanimous behavior of those animals acts as an alert message before striking of earthquake. • Japanese made an experiment over aquatic animals, as they have high perception of sensing the changes in electric fields. • Since, the shaking of ground disturbs the earth’s electro- magnetic field which is immediately sensed by aquatic animals and behaves unanimously. ICHCI’13
  13. 13. Precursors  Precursor techniques are based on pattern evaluation which are formulated by the Radon emissions of elements like thoron, radon, uranium etc.  The pattern includes the relationship between intensity/velocities of the gases emitted and (2 x half life period of the element). ICHCI’13
  14. 14. Extraction of co-seismic signals  Co-seismic signals are extracted from the underground water.  Using HHT transform technique the frequency and energy of co-seismic signals are extracted using IMF (Intrinsic Mode Function) and EMD (Energy Mode Decomposition) functions respectively. ICHCI’13
  15. 15. Earthquake Early Warning Systems ICHCI’13
  16. 16. Proposed System A new modern technical approach is proposed to detect the earthquake using seismic waves. Analysis on seismic wave produces seismic parameters like energy, frequency, surface magnitude, wavelength and rupture area. More detail experimentation is shown in the following flow chart diagram. ICHCI’13
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  18. 18. Experimentation Methodology Stage 1 : Seismic wave acquisition  Seismic waves are combination of P and S-waves which are recorded by a seismogram.  The seismic waves can be in two forms 1. Image format 2. Signal format  Seismic signal is chosen, instead of seismic image, for the experimentation as it is more clear in representation and free from external noises. ICHCI’13
  19. 19. Seismic Image Seismic Signal ICHCI’13
  20. 20. All the seismic signals are bought from 1. SSA (Seismological Society of America) 2. JMA (Japan Metrological Agency) 3. USGS (United State Geological Survey) 4. SCEC (Southern California Earthquake data Centre) ICHCI’13
  21. 21. Stage 2: De-noising  Seismic signal may contain certain noisy data which are to be minimized.  Hence, these seismic signals are subjected to a technique called De-noising using Haar wavelet.  The following figure shows the levels in decompositions in de-noising process and the de-noised signal. ICHCI’13
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  23. 23. Stage 3: FFT Spectrum  The de-noised signal is further processed to extract certain parameters which include 1. Histograms - frequency distribution graph. 2. Cumulative Histogram - cumulative frequency distribution graph. 3. Autocorrelation – computes periodicity in seismic signal. 4. FFT Spectrum – represents graphical relation between energy and frequency of seismic signal. ICHCI’13
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  25. 25. Stage 4: Feature extraction from the graph  Parameters like energy and frequency of seismic signal can be extracted from FFT Spectrum.  The maximum energy level value is computed along with its frequency value from the following graph. ICHCI’13
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  27. 27. Stage 5: Other seismic parameters  Other seismic parameters include, wavelength computed using formula represents wavelength represents speed of seismic wave represents frequency /v f ICHCI’13
  28. 28.  Surface magnitude is computed using E represents energy of seismic wave Ms represents surface magnitude  Rupture area is computed using Ms represents surface magnitude A represents rupture area 10log |1.5 11.8|sE M 10log |1.02 4.01|sA M ICHCI’13
  29. 29. Signal No. Energy (ergs) Frequency (Hz) Wavelength (mts) Surface Magnitude(Ms) Rupture Area (cm2) Earthquake detection 1 659 27.1 17.71 5.9 0.32 Yes 2 11306 25.5 18.82 5.1 0.10 Yes 3 11370 129.4 00.03 0.0 0.00 No 4 4197 61.2 07.84 5.4 0.19 Yes 5 1535 42.1 11.40 5.5 0.22 Yes 6 78000 80 00.41 0.0 0.00 No 7 191200 21.8 22.02 4.3 0.37 Yes 8 6700 104.9 00.32 0.0 0.00 No 9 195100 80 00.42 0.0 0.00 No 10 3212 24.5 19.59 5.5 0.21 Yes 11 1524 28.6 01.17 0.0 0.00 No 12 28770 16.5 29.09 4.8 0.01 Yes 13 19444 31.6 15.19 5.0 0.04 Yes 14 630 116.4 00.28 0.0 0.00 No 15 3348 24.45 01.37 0.0 0.00 No Sample dataset ICHCI’13
  30. 30. Based on the experimentation, the minimum surface magnitude fixed value is 4. If the Ms 4 earthquake, else Ms No earthquake. In order to predict the earthquake the seismic signals are to be extracted prior to the occurrence of earthquake, this can be done using GPR (Ground Penetrating Radar). Those extracted signals are analyzed as above stated procedure to obtain parameters. Since we can get Magnitude value we can predict the severity of earthquake in advance. ICHCI’13
  31. 31. Conclusions The proposed methodology detects the earthquake with five seismic parameters. Simple and modern technical approach. Magnitude based detection/prediction. Same approach can be used to predict the earthquake by extracting changes in seismic signals from underground. ICHCI’13
  32. 32. Future Enhancements Different wavelets can be used instead of haar wavelet to de-noise. Certain seismic parameters like seismic moment, volcanic eruption rates can be considered to improve efficiency. ICHCI’13
  33. 33. ICHCI’13