Paleoearthquakes at Frazier Mountain, California delimit extent and frequency of past San Andreas Fault ruptures along 1857 trace

摘要: Large earthquakes are infrequent along a single fault, and therefore historic, well-characterized exert strong influence on fault behavior models. This is true of the 1857 Fort Tejon earthquake (estimated M7.7–7.9) southern San Andreas Fault (SSAF), but an outstanding question whether 330 km long rupture was typical. New paleoseismic data for six to seven ground-rupturing Big Bend SSAF restrict pattern possible ruptures stretch fault. In conjunction with existing sites, we show that over last ~650 years, at least 75% surface shorter than earthquake, estimated lengths 100 <300 km. These results suggest unusual, perhaps leading open interval, return pre-1857 would increase rate M7.3–M7.7 earthquakes.