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Near‐surface properties of an active fault derived by joint interpretation of different geophysical methods ‐ the Arava/Araba Fault in the Middle East
Author(s) -
Weber M.,
Helwig S.L.,
Bauer K.,
Haberland Ch.,
Koch O.,
Ryberg T.,
Maercklin N.,
Ritter O.,
Schulze A.
Publication year - 2012
Publication title -
near surface geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.639
H-Index - 39
eISSN - 1873-0604
pISSN - 1569-4445
DOI - 10.3997/1873-0604.2012031
Subject(s) - geology , fault (geology) , lithology , tectonics , seismology , precambrian , transform fault , joint (building) , active fault , geophysics , petrology , paleontology , architectural engineering , engineering
The motion of tectonic plates is accommodated at fault zones. One of the unanswered questions about fault zones relates to the role they play in controlling shallow and local hydrology. This study focuses on the Arava/Araba Fault (AF) zone, the southern portion of the Dead Sea Transform (DST) in the Middle East. We combine seismic and electromagnetic methods (EM) to image the geometry and map the petro‐physical properties and water occurrence in the top 100 m of this active fault. For three profiles, P‐velocity and resistivity images were derived independently. Using a neural network cluster analysis three classes with similar P‐velocity and resistivities could then be determined from these images. These classes correspond to spatial domains of specific material and wetness. The first class occurs primarily east of the fault consisting of ‐wet‐ sand (dunes) and brecciated sediments, whereas the second class composed of similar material located west of the fault is ‐dry‐. The third class lies at depth below ca. 50 m and is composed of highly deformed and weathered Precambrian rocks that constitute the multi‐branch fault zone of the AF at this location. The combination of two independent measurements like seismics and EM linked by a stringent mathematical approach has thus shown the potential to delineate the interplay of lithology and water near active faults.