Style and Distribution of Slip at the Margin of a Pull‐Apart Structure: Geodetic Investigation of the Southern Dead Sea Basin

Abstract

AbstractWe present a new analysis of crustal deformation along the southern Dead Sea pull‐apart basin, located at the southern part of the Dead Sea Fault (DSF). Using geodetic measurements of new and dense Global Positioning System network, we obtain the station velocities across the margin of this structure. We run a set of 2‐D and 3‐D models and find that the total left‐lateral strike‐slip rate of ~4.8 mm/yr is divided between the western (Sedom Fault) and eastern main boundary faults of the pull‐apart basin. Different locking depths of the western and eastern boundary faults suggest asymmetrical basin. General extension of the southern Dead Sea basin of ~0.4 mm/yr and additional shallow extension of ~0.5 mm/yr of the Sedom Fault is observed. The southern fault boundary, the Amazyahu transverse Fault, is obliquely deformed in the general direction of the DSF, transferring ~2.5 mm/yr of slip rate from southeast to northwest. The Sedom and Amazyahu faults are also found to be creeping at shallow depths and at steady rates. The depth of shallow creep correlates with the depth of thick rock salt layers deposited within the basin. The rock salt probably serves as lubricant material on the fault with a relatively low friction coefficient. This unique situation allows the fault to creep at almost constant velocity. Our observations suggest that shallow creep may also occur along additional segments of the DSF where thick rock salt layers are relatively shallow.