Can we forecast an Earthquake??? In the next minute there will be an earthquake somewhere in the world! This sentence is correct (we have seen that there is at least 150 earthquake of magnitude every hour!) but quite useless. Long vs Short Term forecast Long term: Geological observation: Paleoseismology Mapping Faults Seismic Gaps Geodesy Geophysics: Earthquake processing Stress propagation Earthquake Simulations SEISMIC HAZARDS MAPS Short term Foreshocks Animal Behavior Rock Conductivity Rock Seismic Velocity Water Level Gas Emission (Radon) EVACUATION Problems with Short Term Every earthquake seems to behave in a different way and in general we make the observations only after the event. The only real forecast with evacuations happen in February 1975 in China (Haicheng) but none of the observed sign of the 1975 event were visible next year in TangShan (China) when an earthquake killed people. The recurrence time is too long to test our models Haicheng earthquake Seismic Gap (1) USGS, 1989 Seismic Gaps (2) From Brumbagugh, 1999 The SCEC 3.0 velocity field Velocity and velocity gradient of all segments Maximum horizontal shear Relation between seismicity and interseismic deformation Historical Major Earthquakes 1857Fort Tejon San Francisco Imperial Valley Loma Prieta Landers Northridge Hector Mine7.2 The BIG Ones Timeline years Recurrence Intervals 150 years40 years24 years 210 years 400 years Average time between major earthquake events on a fault segment Short recurrence intervals are identified along faults of high stress accumulation rate 400 Imperial Parkfield Mojave Santa Cruz Peninsula Calaveras Concord more repeating earthquakes Paleoseismic Current motion in the Aegean-Caucuses (with respect to Eurasia) McClusky et al. (2000) Stain et al, 1997 Anatolian Fault Hazards Maps City Planning Schools From Brumbagugh, 1999 Education