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Articles & Research
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Data Resources Category
Data Resources Category |
Scientific Paper |
Research
Title |
Dead Sea Basin Imaged by Ambient Seismic Noise Tomography |
Published by
(sources) |
Pure and Applied Geophysics, 169, 4, 615-623 |
Carried out by
(authors) |
Ayman mohsen |
Issue Year |
2012 |
Abstract |
In the framework of the Dead Sea Integrated Research
project (DESIRE), 59 seismological stations were deployed in the region of the
Dead Sea Basin. Twenty of these stations recorded data of sufficiently high
quality between May and September 2007 to be used for ambient seismic noise
analysis. Empirical Green’s functions are extracted from cross-correlations of
long term recordings. These functions are dominated by Rayleigh waves, whose
group velocities can be measured in the frequency range from 0.1 to 0.5 Hz.
Analysis of positive and negative correlation lags of the Green’s functions
makes it possible to identify the direction of the source of the incoming
energy. Signals with frequencies higher than 0.2 Hz originate from the
Mediterranean Sea, while low frequencies arrive from the direction of the Red
Sea. Travel times of the extracted Rayleigh waves were measured between station
pairs for different frequencies, and tomographically inverted to provide
independent velocity models. Four such 2D models were computed for a set of
frequencies, all corresponding to different sampling depths, and thus together
giving an indication of the velocity variations in 3D extending to a depth of
10 km. The results show low velocities in the Dead Sea Basin, consistent with previous
studies suggesting up to 8 km of recent sedimentary infill in the Basin. The
complex structure of the western margin of the Basin is also observed, with
sedimentary infill present to depths not exceeding 5 km west of the southern
part of the Dead Sea. The high velocities associated with the Lisan salt diapir
are also observed down to a depth of ~5 km. The reliability of the results is
confirmed by checkerboard recovery tests.
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