Earthquakes and Earthquake Prediction

1. Earthquakes and Earthquake Prediction Andrei Gabrielov Purdue University West Lafayette, IN, USA www.math.purdue.edu/~agabriel

2. San Francisco, April 18, 1906

3. Plate Tectonics • Major tectonic plates and world seismicity

4. Plate Tectonics • Plate boundaries and tectonic faults

5. North American Plate Pacific Plate

6. Elastic Rebound Theory Discovered after the great 1906 San Francisco earthquake (before plate tectonics theory).

7. Elastic Rebound Theory Discovered after the great 1906 San Francisco earthquake (before plate tectonics theory).

8. Elastic Rebound Slow build-up of deformation (strain) in the rocks by plate motion. Strain (energy) is released suddenly as fault slips.

9. Earthquake Focus and Epicenter

10. Earthquakes generate elastic waves: Body waves: P (pulse), S (transverse) Surface waves: R (Rayleigh), L (Love) Surface waves S-wave P-wave  Time  First arrival Seismogram for a distant earthquake

11. A wave pulse (P-wave) Animation courtesy of Dr. Dan Russell, Kettering University http://www.kettering.edu/~drussell/demos.html

12. Transverse wave (S-wave) Animation courtesy of Dr. Dan Russell, Kettering University http://www.kettering.edu/~drussell/demos.html

13. Rayleigh wave Animation courtesy of Dr. Dan Russell, Kettering University http://www.kettering.edu/~drussell/demos.html

15. Seismic Waves in the Earth Seismic waves through the Earth’s interior that indicate structure (crust, mantle, outer core, inner core, etc.)

16. Magnitude • Measure of the ENERGY released in the earthquake, based on vibration caused by seismic waves • Logarithmic scale ― M = 6 is ten times greater vibration, and a hundred times more energy, than M = 5 (at the same distance) • Should not be mistaken for INTENSITY― the measure of the damage caused by the earthquake

17. Moment MagnitudeMw Focus or hypocenter (point of initiation of the rupture) Epicenter (location on Earth’s surface above the hypocenter) * Depth Moment = M0 = µ A D(dyne-cm) (dyne is a unit of force) µ = shear modulus ~ 32 GPa in crust (~3.2 x 1011 dynes/cm2), ~75 GPa in mantle (a measure of strength of rocks)A = LW = area (cm2), D = average displacement (cm) Mw = 2/3 log10(M0) - 10.7

18. Gutenberg-Richter Law

19. Worldwide earthquakes per year (from USGS):

20. Aftershocks • Earthquakes that happen following a mainshock, in the same region but of smaller magnitude • Aftershock frequency distribution in time t after the mainshock satisfies Omori Law: • Bath’s Law: Aftershock’s magintude is approximately 1.2 less than mainshock’s • Aftershocks frequency-magnitude distribution satisfies Gutenberg-Richter law

21. World’s largest earthquakes since 1900

23. Continental USA largest earthquakes

24. Largest Earthquakes in the Continental USA

26. Strong Earthquakes Nucleate in Some “Dangerous” Structures (D-nodes) Gelfand, et al., 1976. Qualitatively, D-nodes are recognized • by local depression on the background of NG‑Q depression (“local tension on the background of general compression”) • by proximity of hydrothermal reservoirs

27. Intensity Clustering Range of correlation in space Magnitude- lgN lgN frequency Precursory state Non-precursory state relation m m Earthquake prediction A strong earthquake is preceded by the following changes in seismicity:

28. POSSIBLE OUTCOMES OF PREDICTION

29. Intermediate-term (5 yrs) PredictionAlgorithm M8-MSc, Keilis-Borok and Kossobokov

30. Predicting the 3/11/2011 M9 earthquake in Japan

31. Predicting the 4/11/2012 M8.6 and M8.2 Earthquakes off the Western coast of Northern Sumatra, Indonesia

32. FRONTIERS OF SIMILARITY Precursors have been defined for earthquakes. Only the final scale was adjusted for starquakes.

33. SOCIO-ECONOMIC PREDICTIONS

34. Prediction of US Recessions

35. US PRESIDENTIAL ELECTIONS (Keilis-Borok and Lichtman) Prediction is based on thirteen socio-economic and political factors. Victory of challenging party is predicted when 6 or more factors are in its favor. Otherwise victory of incumbent party is predicted. Predictions published months in advance: all 8 - correct Retrospective Analysis: 1860 - 1980 * years when popular vote was reversed by electoral vote. Red- incumbent won, blue – challenger won.

36. 13 Keys to Presidency (Keilis-Borok and Lichtman) Answer YES favors re-election of the incumbent party Key 1: (Party Mandate): After the midterm elections, the incumbent party holds more seats in the U.S. House of Representatives than it did after the previous midterm elections. Key 2: (Contest): There is no serious contest for the incumbent-party nomination. Key 3: (Incumbency): The incumbent-party candidate is the sitting president. Key 4: (Third party): There is no significant third-party or independent campaign. Key 5:(Short-term economy): The economy is not in recession duringthe election campaign. Key 6: (Long-term economy): Real per-capita economic growthduring the term equals or exceeds mean growth during the previous two terms. Key 7: (Policy change): The incumbent administration effects major changes in national policy. Key 8: (Social unrest): There is no sustained social unrest during the term. Key 9: (Scandal): The incumbent administration is untainted by major scandal. Key 10: (Foreign/military failure): The incumbent administration suffers no major failure in foreign or military affairs. Key 11: (Foreign/military success): The incumbent administration achieves a major success in foreign or military affairs. Key 12: (Incumbent charisma): The incumbent-party candidate is charismatic or a national hero. Key 13: (Challenger charisma): The challenging-party candidate is not charismatic or a national hero.

37. Answers for the 2012 presidential election (published 28 months before the election) • KEY 1: Party mandate. After the midterm elections, the incumbent party holds more seats in the U.S. House of Representatives than it did after the previous midterm elections. (FALSE) • KEY 2: Contest. There is no serious contest for the incumbent-party nomination. (TRUE) • KEY 3: Incumbency. The incumbent-party candidate is the sitting president. (TRUE) • KEY 4: Third party. There is no significant third-party or independent campaign. (TRUE) • KEY 5: Short-term economy. The economy is not in recession during the election campaign. (TRUE) • KEY 6: Long-term economy. Real per capita economic growth during the term equals or exceeds mean growth during the previous two terms. (FALSE) • KEY 7: Policy change. The incumbent administration effects major changes in national policy. (TRUE) • KEY 8: Social unrest. There is no sustained social unrest during the term. (TRUE) • KEY 9: Scandal. The administration is untainted by major scandal. (TRUE) • KEY 10: Foreign/military failure. The administration suffers no major failure in foreign or military affairs. (TRUE) • KEY 11: Foreign/military success. The administration achieves a major success in foreign or military affairs. (FALSE) • KEY 12: Incumbent charisma. The incumbent-party candidate is charismatic or a national hero. (FALSE) • KEY 13: Challenger charisma: The challenging-party candidate is not charismatic or a national hero. (TRUE)