Dead Sea gives life to a unique seismic calibration experiment

Abstract

An unusual seismic and hydro‐acoustic experiment involving large underwater chemical explosions has been conducted in the Dead Sea. The purpose of this creative, cost‐efficient venture was to improve monitoring and verification of the Comprehensive Test Ban Treaty (CTBT) in the Middle East.The goals of the experiment were to calibrate the regional travel times of the seismic waves from the explosions; to provide data for source characterization; and to improve detection, location, and discrimination capabilities of the International Monitoring System (IMS) stations. From a seismologist's point of view, the experiment's main 5‐ton explosion exceeded expectations. The blast was recorded at 8 IMS stations (including PDYAR in Russia, more than 5000 km away), with the estimated location only 2.3 km from ground truth, and an event magnitude of mb=3.9 [Center for Monitoring Research, 1999]. These results compare to the predicted local magnitude of about 4 and the maximal observable range of about 2600 km [Gitterman, 1998]. A lack of a detectable signal on some nearer stations will likely reveal important path effects.