Microseismicity Distribution In The Southern Dead Sea Basin And Its Implications On The Structure Of The Basin

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Journal Title, Volume, Page: 
Geophys. J. I nt. (2012) 188, 873–878
Year of Publication: 
B. Braeuer
GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
Guenter Asch
GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
R. Hofstetter
Ch. Haberland
GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
D. Jaser
Natural Resources Au thority (NRA), Eight circle, P.O. Box 7 , Amman, Jordan
R. El-Kelani
An-Najah National University, P.O. Box 7, Nablus, West Bank, Palestine
M . Weber
Institute of Earth and Environmental Science, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, University of Potsdam, Germany
Preferred Abstract (Original): 
While the Dead Sea basin has been studied for a long time, the available knowledge about the detailed seismicity distribution in the area, as well as the deeper structure of the basin, is limited. Therefore, within the framework of the international project DESIRE (DEad Sea Integrated REsearch project), a dense temporary local seismological network was operated in the southern Dead Sea area. We use 530 local earthquakes, having all together 26 730 P- and S-arrival times for a simultaneous inversion of 1-D velocity models, station corrections and precise earthquake locations. Jackknife tests suggest an accuracy of the derived hypocentre locations of about 1 km. Thus, the result is the first clear image of the absolute distribution of the microseismicity of the area, especially in depth. The seismicity is concentrated in the upper crust down to 20 km depth while the lower limit of the seismicity is reached at 31 km depth. The seismic events at the eastern boundary fault (EBF) in the southern part of the study area represent the northward transform motion of the Arabian Plate along the Dead Sea Transform. North of the Boqeq fault the seismic activity represents the transfer of the motion in the pull-apart basin from the eastern to the western boundary. We find that from the surface downward the seismic events are tracing the boundary faults of the basin. The western boundary is mapped down to 12 km depth while the EBF reaches about 17 km depth, forming an asymmetric basin. One fifth of the data set is related to a specific cluster in time and space, which occurred in 2007 February at the western border fault. This cluster is aligned vertically, that is, it is perpendicular to the direction of the dominating left-lateral strike-slip movement at the main transform fault.
Microseismicity _Distribution _In _The _Southern _Dead _Sea _Basin _And _Its _Implications _On _The _Structure _Of _The _Basin.pdf927.92 KB