The shallow P-velocity structure of the southern Dead Sea basin derived from near-vertical incidence reflection seismic data in project DESIRE

As a part of the DEad Sea Integrated REsearch (DESIRE) project a seismic near-vertical incidence reflection (NVR) experiment with a profile length of 122 km was completed in spring 2006. The profile crossed the southern Dead Sea basin (DSB), a pull-apart basin due to the strike-slip motion along the Dead Sea Transform (DST). The DST is part of a multi-stage left lateral fault system which connects the spreading centre in the Red Sea with the Taurus collision zone in Turkey over a length of about 1,100 km. The experiment, with the main aim to explore lithologic structures in this area, was carried out in a roll-along acquisition procedure and comprises 972 source locations and 1.045 receiver locations. Each source was recorded by ~180 active receivers and a field dataset with 175,000 traces was created. From this dataset, 124,444 P-wave first-break traveltimes has been picked for this study. A tomographic inversion was carried out, resulting in a 2-D P-wave velocity model. Within the DSB, the model shows clearly the position of the Lisan salt diapir, identified by a high velocity zone. Further features are low velocity zones with P-velocities of ~3 km/s embedded in regions with ~4 km/s in the shallow part on the west side of the DSB. To verify the existence of this low velocity zone, a recovery test and also inversions with different starting models has been carried out. Correlations between the velocity model, a migrated NVR depth section and a geological model based on borehole and surface information will be presented.