Amotz Agnon
Hebrew University Hermann Institute of Earth Sciences
Israel
Title: SDEIGWI-Space detection of Earthquake induced ground water injection
Biography
Biography: Amotz Agnon
Abstract
An anomalous concentration of barium has been reported in Lake Lisan (paleo Dead Sea) sediments showing earthquake induced deformation structures (seismites). Katz et al. (2008) were inclined to reject the hypothesis that these anomalies were formed by injection of Ba-rich reduced brines from the deep crustal depths into the lake. Regardless of the source of these chemical anomalies, large destructive earthquakes are frequently associated with injection of water originating in deep aquifers into lakes. This creates an opportunity to detect these processes from space, and to search for precursory phenomena for combining in earthquake alarm programs. For the Dead Sea, one should focus on injection of solutions lighter than the surface brine. Due to the high density of the Dead Sea brine, and it overall negative precipitation- evaporation balance, this task may prove doable even for brines arriving from considerable depth. The Dead Sea surface waters are typically super saturated with respect to sodium- chloride , evidenced by the intensive precipitation of halite on ropes and any object dipped into the lake. Brines that surface due to being warmer than ambient surface water give a detectable infrared signal in the form of a hot spot. Cold spots are also detected on the surface where buoyancy is due to lower salinity. Both cases are temporally associated with small earthquakes.