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Thailand Training Program in Seismology and Tsunami Warnings, May 2006 PowerPoint Presentation
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Thailand Training Program in Seismology and Tsunami Warnings, May 2006

Thailand Training Program in Seismology and Tsunami Warnings, May 2006

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Thailand Training Program in Seismology and Tsunami Warnings, May 2006

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  1. Forecasting Earthquakes Thailand Training Program in Seismology and Tsunami Warnings, May 2006

  2. Forecasting Earthquakes • ・ Difference between Predictions and Forecasts • ・ Early Efforts in Earthquake Prediction • ・ Long-term Forecasting

  3. Earthquake Predictions versus Forecasts Predictions have specific times, locations, and magnitudes for future earthquakes. Forecasts are more long-term estimates of earthquake occurrences with probability information.

  4. Loading Cycle Interseismic Preseismic Coseismic Postseismic Forecast Short-term (minutes to weeks) Intermediate (months to 10 years ) Long-term (> 10 years)

  5. What is needed in an earthquake prediction ? 1. Time 2. Location 3. Magnitude Frequency of Occurrence of Earthquakes Allen, 1996

  6. What is needed in an earthquake prediction ? 1. Time 2. Location 3. Magnitude 4. Indication of confidence (window) 5. Prediction must be presented in accessible form for later evaluation 6. Chance earthquake occurs anyway as a random event Allen, 1996

  7. Optimism in the 1960’s and 1970’s ‘Now, when will earthquake prediction be possible and an efficient Forewarningservice available ? …if we start the project presented here we should be able to answer the question with sufficient certainty within ten years.’ The Japanese Blueprint (Tsuboi et al, 1962) ‘Based on an assessment of worldwide observations and findings over the past few years, it is the panel’s unanimous opinion that the development of an effective earthquake prediction capability is an achievable goal. …with appropriate commitment and level of effort, the routine announcement of reliable predictions may be possible within ten years…’ Panel of the US National Research Council (Allen et al., 1976) In actuality: Can only forecast earthquakes and mitigate hazard

  8. Successes and Failures ‘Predicted’ ・1973 Blue Mountain Lake ・1975 Haicheng, China ・1978 Oaxaca, Mexico ・1978 Izu, Japan ‘Not Predicted’ ・1976 Tangshan, China (M7.7 650,000 est. casualties) ・2004 Parkfield, California

  9. Blue Mountain Lake, NY

  10. ‘Dilatancy’

  11. Scholz et al., 1973 Dilatancy hardening

  12. Prediction of the 1975 Haicheng, China Earthquake (M7.3) Prediction based on foreshocks and animal behavior saved many lives

  13. Short-Term Crustal Deformation Precursor (M 8.1 Tonankai Earthquake 1944) Mogi, 1984

  14. Short-Term Electromagnetic Precursor 1989 Loma Prieta Earthquake Fraser-Smith, et al., 1990

  15. Intermediate-Term: Seismicity Patterns 1978 Oaxaca, Mexico (Ohtake et al., 1981) ‘Mogi Doughnut’ Dilatancy Hardening

  16. Intermediate-Term: Crustal Deformation 1964 Niigata earthquake Mogi, 1985

  17. Intermediate-Term: Water and Chemical M 7.0 Izu earthquake 1978 Wakita, 1981

  18. ‘Successfully’Predicted ・1973 Blue Mountain Lake ・1975 Haicheng, China ・1978 Oaxaca, Mexico ・1978 Izu, Japan

  19. Parkfield Earthquake Prediction Experiment 95% probability that M5.5 to 6 will occur 1985-1993. • Based on • Recurrence pattern • Characteristic waveforms

  20. Bakun and McEvilly, 1979 • Repeating Characteristic Earthquakes • M5 foreshock 17 minutes before 1934 and 1966 events

  21. For short-term prediction, there have been more negative results than positive results: Not Predicted ・1976 Tangshan, China (M7.7 650,000 est. casualties) ・2004 Parkfield, California Other precursors have not been consistently seen

  22. Why has there been lack of continued success in observing precursors? • Animal experiments have failed • Original observations were hindsight • Instrumentation • Geology dependent (including lights and piezoelectric effects) • Predictive algorithms have not worked (at least short-term) • Earthquakes may be non-characteristic • No connection to tides or planetary alignment • No psychics have made consistent predictions

  23. Earthquake Forecasting Short-term minutes to weeks Intermediate-term months to 10 years Long-term > 10 years

  24. Recurrence times of earthquakes • to forecast future earthquakes • Using historic data • Using geologic data

  25. Earthquake Cycle Periodic Time-predictable Slip-predictable Shimazaki and Nakata, 1980

  26. History of Nankai Earthquakes

  27. PALEOSEISMOLOGY Trenching faults to find geological evidence of past earthquakes Pallet Creek site on the San Andreas fault

  28. Earthquake Cycle Periodic Time-predictable Slip-predictable Shimazaki and Nakata, 1980

  29. Probability Conditional Probability 100 years

  30. Variability in Repeating Earthquakes Well defined recurrence interval (Small variability) Wide range of recurrence intervals (Large variability)

  31. Loma Prieta 1989 Parkfield 2004 Hector Mines Landers 1992 Probabilistic Earthquake Forecasting for California

  32. USGS National Hazard Maps http://geohazards.cr.usgs.gov/eq/

  33. Ground Shaking Surface Faulting Landslides and Liquefaction Avalanches and soil (mud flows) Earthquake Hazards

  34. What about Thailand? ・ Low Seismicity ・ No Historical Earthquakes ・ Active Faults (?) ・ Probability is low for future earthquakes But earthquakes can happen in low probability regions and offshore NEIC Catalog Seismicity (M>4.5) 1964-2005

  35. Future Outlook Will we be able to predict earthquakes in the future ? Long-term: Probably Intermediate term: Maybe Short-term: Maybe

  36. Don’t forget that the precursor to a tsunami is the earthquake.

  37. Parkfield Earthquake Prediction Experiment

  38. Four phases Interseismic Preseismic Coseismic Postseismic Loading or deformation cycle

  39. For short-term precursors, there are currently more ‘negative’ results than ‘positive’results. Johnston and Linde, 2002 Kanamori et al., 1996

  40. Earthquake Prediction Researchin the 1970’s Distance Measurements on the San Andreas fault Matsushiro strainmeter

  41. Laser Distance Measurements

  42. M 6.8 Nisqually 2001 Ground Shaking

  43. Surface faulting Bei-Fung Bridge near Fung-Yan city, 1999 Chi-Chi, Taiwan earthquake

  44. 1964 Niigata Earthquake Liquefaction