The Science (& Pseudo-science) of Earthquake PredictionWhy are earthquakes so interesting? The Impact Casualties (Deaths and Injuries)Why are earthquakes so interesting? The Human DimensionWhy are earthquakes so interesting? The Devastation and the InequalityWhy are earthquakes so interesting? A Global ProblemWhy are earthquakes so interesting? Increasing LossesIs earthquake prediction a solution?Earthquake PredictionEarthquake PredictionWhat might you need to know to make an EQ prediction?Successful and Unsuccessful Predictions in ChinaTangshan after EQPrecursor?1989 Browning Prediction1989 Browning PredictionBrowning’s “Loma Prieta Prediction”Scientific MethodBrowning’s MethodThe Parkfield ExperimentThe Parkfield ExperimentThe Parkfield ExperimentThe Parkfield ExperimentConclusionReferencesENGR 100wENGR 100wThe Science The Science (& Pseudo(& Pseudo--science) science) of Earthquake Predictionof Earthquake PredictionThalia AnagnosProfessor, EngineeringSan José State UniversityENGR 100wENGR 100wWhy are earthquakes so interesting?Why are earthquakes so interesting?The Impact The Impact Source: USGShttp://earthquake.usgs.gov/eqcenter/top10.phpEarthquake Date Magnitude Number of DeathsChile (& tsunami) May 22, 1960 9.5 4,000 to 5,000Alaska (& tsunami) Mar. 28, 1964 9.2 125Sumatra (& tsunami) Dec. 26, 2004 9.0 283,106Michoacan, Mexico Sept. 19, 1985 8.0 9,500 (estimates as high as 30,000)San Francisco Apr. 18, 1906 7.8 3,000Sichuan, China May 12, 2008 7.9 69,180Taiwan Sept. 20, 1999 7.7 2,297Pakistan Oct. 8, 2005 7.6 80,361Tangshen, China Jul. 27, 1976 7.5 255,000 (estimates as high as 655,000)Loma Prieta Oct. 18, 1989 6.9 63Kobe, Japan Jan. 16, 1995 6.9 5,502Northridge Jan. 17, 1994 6.7 60ENGR 100wENGR 100wCasualties (Deaths and Injuries)Casualties (Deaths and Injuries)• The majority of deaths occur in collapsed buildings – (China schools).• In addition to deaths, there are many less severe casualties (hospitalized and non-hospitalized)ENGR 100wENGR 100wWhy are earthquakes so interesting?Why are earthquakes so interesting?The Human DimensionThe Human DimensionRefugee camp San Francisco Earthquake, 1906400,000 people homeless Source: The California Historical SocietyTemporary shelters in Kobe, 1995300,000 people homelesswww.lib.kobe-u.ac.jp/directory/eqb/photo/sakai/eng/e-V4/e-VA_4_01.htmlENGR 100wENGR 100wWhy are earthquakes so interesting?Why are earthquakes so interesting?The Devastation and the InequalityThe Devastation and the Inequality1999 Izmit, Turkey EQM7.617,118 deathsSource: Mehmet Celebi, USGSENGR 100wENGR 100wWhy are earthquakes so interesting?Why are earthquakes so interesting?A Global ProblemA Global ProblemSource: USGShttp://earthquake.usgs.gov/regional/world/seismicity/index.phpENGR 100wENGR 100wWhy are earthquakes so interesting?Why are earthquakes so interesting?Increasing LossesIncreasing LossesSource: Munich Reinsurance1995Kobe: $100 billion1999Izmit: $13 billionTaiwan: $12 billionTyphoon BartHurricane FloydSwiss floodsFor comparison:Hurricane Katrina $100 billionENGR 100wENGR 100wIs earthquake prediction a solution?Is earthquake prediction a solution?• Wouldn’t it be great if we could predict earthquakes? Then we could:– Evacuate people– Turn off the gas– Have emergency services & shelters in place– Alert trains to slow down or stay in the station– Turn off equipment– Open fire station doors– Program elevators not to operate– ...much moreENGR 100wENGR 100wEarthquake PredictionEarthquake Prediction• How is earthquake prediction defined?Turn to your neighbor and discuss what are the elements of an “earthquake prediction”ENGR 100wENGR 100wEarthquake PredictionEarthquake Prediction• A reliable earthquake prediction should occur BEFORE the event and include:– Location–Time–Size– How likely– Reasonsbehind prediction (justification)ENGR 100wENGR 100wWhat might you need to know to What might you need to know to make an EQ prediction?make an EQ prediction?• Tectonic environment– Edge of a plate? Interior of a plate?– Transform fault? Subduction zone?– Rate at which plates are moving• History of earthquakes in the area• What types of precursors precede EQs?–EQ swarms?– Dogs missing?– Changes in water table?– Anomalous electrical activity in the ground?• What triggers earthquakes– Tides?– High stress?ENGR 100wENGR 100wSuccessful and Unsuccessful Successful and Unsuccessful Predictions in ChinaPredictions in China• Winter 1975, Haicheng evacuated (pop. ~150,000)• Unusual observations over months– changes in land elevation – changes in ground water levels – widespread accounts of peculiar animal behavior – regional increase in seismicity – finally, increase in foreshock activity triggered evacuation warning • M7.3 EQ occurred Feb. 4, 1975• Possibly 150,000 lives saved• July 28, 1976, M 7.6 EQ hits Tangshan (pop. ~1 million)– No precursors– 250,000 to 600,000 people diedENGR 100wENGR 100wTangshan after EQTangshan after EQ(hi.baidu.com, 2009)85% of buildings collapsedENGR 100wENGR 100wTectonic Information: Spaced-based measurements (VLBI and GPS) show that PAC-NA motion in CA is ~50 mm/yr.VLBI = Very Long Baseline Interferometryusing radio telescopesENGR 100wENGR 100wPrecursor?Precursor?• Each cross marks an earthquake recorded in the New Madrid seismic zone since 1974. Source: USGS • What does this mean? Is a major earthquake imminent?ENGR 100wENGR 100w1989 Browning Prediction1989 Browning Prediction• Dr. Iben Browning (a climatologist) predicted an earthquake of M7.0 or larger on the New Madrid Fault Zone on December 3, 1990– Bulging in the earth’s crust caused by the gravitational pull of the earth and the moon would trigger an earthquake on December 3.– Tides were at a peak on December 3.– Published in the Browning Newsletter– News media picked it up, gave it credibility, and claimed he had previously predicted the Loma PrietaearthquakeENGR 100wENGR 100w1989 Browning Prediction1989 Browning Prediction• Believing the prediction was baseless, the scientific community did little to debunk the claim – 6 weeks before 12/3/90 the National EQ Prediction Evaluation Council (NEPEC) issues a report: prediction is as accurate as throwing darts at a calendar – but report is too late• The midwest goes wild– Schools close, factories close, people flee– Many buy EQ insurance– Becomes tourist attraction, sell “It’s our fault!” t-shirts •