High-resolutionseismictomography and magnetotelluric

(MT) soundings of the shallow crust show strong

changes in material properties across the Dead Sea

Transform Fault (DST) in the Arava valley in Jordan. 2D

inversion results of the MT data indicate that the DST is

associated with a strong lateral conductivity contrast of a

highly conductive layer at a depth of approximately 1.5 km

cut-off at a position coinciding with the surface trace of the

DST. At the same location, we observe a sharp increase of

P wave velocities from <4 km/s west of the fault to >5 km/s

to the east. The high velocities in the east probably reflect

Precambrian rocks while the high electrical conductivity

west of the DST is attributed to saline fluids within the

sedimentary filling. In this sense, the DST appears to act as

an impermeable barrier between two different rock

formations. Such a localized fluid barrier is consistent

with models of fault zone evolution but has so far not been

imaged by geophysical methods. The situation at the DST is

remarkably different from active segments of the San

Andreas Fault which typically show a conductive fault

INDEX TERMS:

1515

Geomagnetism and Paleomagnetism: Geomagnetic induction;

7205 Seismology: Continental crust (1242); 8005 Structural

Geology: Folds and folding; 8180 Tectonophysics: Tomography.

Citation:

Ritter, O., T. Ryberg, U. Weckmann, A. Hoffmann-

Rothe, A. Abueladas, Z. Garfunkel, and DESERT Research

Group, Geophysical images of the Dead Sea Transform in Jordan

reveal an impermeable barrier for fluid flow.

30(14), 1741, doi:10.1029/2003GL017541, 2003.