HISTORY, ARCHAEOLOGY, AND GEOLOGY OF EARTHQUAKES: EXAMPLES FROM THE DEAD SEA FAULT

Historical accounts on natural phenomena in general and ýearthquakes in particular are often considered dubious. Therefore they should be verified by field observations, which can ýprovide independent tests. Our interdisciplinary ýpalaeo- and archaeo-seismic research of historical earthquakes along the Dead ýSea Fault shows that analyses of historical information can yield reasonable ýestimates of the rupture locations. Assuming the same reliability for other ýhistorical cases we estimate the locations of all the strong earthquakes of the last ýtwo millennia in Israel, based on historical texts. Bearing in mind the ýuncertainties associated with the interpretation of historical accounts, we discern ýdistinct short-lived patterns of earthquake occurrence. One example is an almost ýperiodic recurrence of large earthquakes between the Dead Sea and the Sea of ýGalilee starting with the 31 BC earthquake and continuing with the AD 363, 749, ýand 1034. Two smaller earthquakes of 1546 and 1927 followed, altogether ýexhibiting a mean recurrence interval of 390±80 years. This pattern is not ýobserved elsewhere along the Dead Sea Fault.ý Another observed pattern is a sequence of north-to-south progressive failures ýthat occurred once in 859, 991, 1033, and 1068 and again in 1170, 1202, and 1293. ýNo similar patterns, neither before nor after these two series are observed. ý The quasi-periodic and sequential failure patterns appear to last only short ýperiods of the order of several decades to a few centuries. Our interpretation also ýshows that it has now been eight centuries since most of the Dead Sea Fault plate ýmargin in Israel sustained significant rupture.ý These examples demonstrate the strength of combining the disciplines of history ýand archaeology in earthquake research, in particular in the old world where ýboth historical records and archaeological sites coexist with active faults. ýDeliberate search for archaeological sites along fault zones holds the potential for ýsignificantly increasing our palaeoseismic database, thus improving the ýunderstanding of faulting and earthquakes.ý