Goals

The Dead Sea Rift / Dead Sea Transform (Figure) acts as the hinge between the Alpine-Himalayan mountain belt and the Afro-Arabian rift system (Figure). The tectonic stability of this region was only recently (18 Ma ago) interrupted by the formation of a transform fault with a left-lateral motion of about 105 km as of today. The nearly linear structure provides us with a natural laboratory to study transform faults. Up to now, no geophysical profile has crossed the Dead Sea rift/the Dead Sea transform. Many details of the crustal structure and the role of this fault for the dynamics of this region are still unknown.

Some of the open questions regarding the crustal structure of the Dead Sea region are:

  • is it a rift, a transform fault or a "strike-slip-rift"?
  • what is the reason for the asymmetric topography towards the East and West of the rift?
  • what is the explanation for the reduced heat flow values in the rift in contrast to the Red Sea?
  • what is the possible role of fluids in this system?

Another central question is that of seismic hazard: studies of historical earthquakes, paleoseismic excavations, and instrumental earthquake studies (Figure) demonstrate that damaging earthquakes were located along the Dead Sea Transform Fault.

The key to these fundamental questions of geodynamics, and to the understanding of the impact of natural forces on society, is a detailed knowledge of the crustal structure in this region. An understanding of the upper mantle dynamics responsible for the plate movement in this area is also necessary.

The location where we study the Dead Sea Transform Fault is the Central Arava Valley (Figure). The proposed study area is located about 100 km away from both the basin of the Dead Sea and the Gulf of Elat/Agaba basin, respectively. The project proposed here is a contribution to a larger research effort in the Dead Sea Rift area that is headed by the GFZ. The seismic, seismological, electromagnetic, gravity and magnetic studies (Figure) represent an integrated part of an interdisciplinary research program, and will provide the basic geophysical framework for other geoscience disciplines.

With this project we also hope to be able to address some of the fundamental questions related to shear zones: 

  • How deep are the "roots" of shear zones?
  • How do the physical properties change close to and within a shear zone?
  • How does the dip of a shear zone change with depth?
  • How are earthquake foci related to local variations in conductivity and/or variations in seismic velocities within a shear zone?

Answering these questions will allow us to contribute to one of the central questions of plate tectonics: How do shear zone work and what controls them?