First results of PS-InSAR analysis of crustal deformation and landslides in Galilee (Israel) and presentation of the Joint German-Israeli Research Program to improve assessments of the seismic hazard generated by the Dead Sea Transform Fault

Abstract

Seismically triggered landslides pose a major seismic hazard in steep terrain. Because of the large potential damage related to landslides a complete seismic hazard assessment should specifically include the hazard posed by landslides. PS analysis with the DLR’s PS-software will be used, to investigate if any landslides are currently active in the cities of Safed, Tiberias, and other towns in the mountainous regions along the DST, which may be susceptible to seismic triggering. The observed regions of motion will be compared against known landslides (Geological Survey of Israel, GSI) and thus verified, if possible. Also, any newly identified instable slopes in the PS-InSAR analysis will be mapped and surveyed in the field. The resulting map of unstable, moving slopes identifies regions at risk of seismically triggered earthquakes. Monitoring the present-day motion on the Dead Sea Transform fault (DST) and identifying potentially locked segments is important for a qualitative hazard assessment. InSAR and PS-InSAR is applied, monitoring the present-day motion on the DST fault and identifying potentially locked segments is important for a qualitative hazard assessment. To ensure a correct interpretation of the 3-D space-borne observations, ascending and descending track observations of the ERS-1/2 and Envisat satellites will be used. At a later stage, dislocation and numerical 3-D boundary element methods to model the observed displacements in terms of their causative motion along the fault (slip rate, strike, dip, locking depth, etc.) and potential stress transfer scenarios constrained by the fault structure and surface strain patterns (in particular vertical vs. horizontal motions) will be applied. The result of these two researches will be added to geophysical studies on the DST performed by project partners at the University of Jena, the Geological Survey and Geophysical Institute of Israel and the Al-Balqa’ Applied University in Jordan. The overall goal is to improve the assessment of the seismic hazard generated by the southern DST, which constitutes the primary seismic hazard for the most populated parts of Israel, Jordan and the Palestinian Authority. The applied methods to achieve the aforementioned investigations will be expounded and first results of the deformation analysis of Tiberias and Safed as well as crustal deformation in the area of the Besan Valley using PS-InSAR will be presented.