The Seismogenic Thickness in the Dead Sea Area

Abstract

Four independent distributions of seismicity in the Dead Sea area underline the occurrence of lower-crustal seismic activity down-to at least 27 km and possibly as deep as 33.6 km. From these distributions, the seismogenic thickness is estimated to be 28.4 ± 2.2 km. The existence of a seismogenic zone extending deep into the lower crust is consistent with an average heat flow of only 40–45 mWm−2 over most regions of Israel, and around 40 mWm−2 in the Dead Sea area in particular. The seismogenic thickness in the Dead Sea area is thus nearly twice the average seismogenic thickness of 15 km observed in southern California. The fact that some seismic activity occurs down-to the Moho in the Dead Sea area suggests that the state of fully plastic deformation is probably not reached in the crust under the seismogenic zone.