The Qadimah Fault has been mapped as a normal fault running through the middle of a
planned $$$50 billion city. For this reason, there is an urgent need to evaluate the seismic
hazard that the fault poses to the new development. Although several geophysical studies
have supported the existence of a fault, the driving mechanism remains unclear. While a fault
controlled by gravity gliding of the overburden on a mobile salt layer is unlikely to be of
concern to the city, one caused by the continued extension of a normal rotational fault due
to Red Sea rifting could result in a major earthquake.
A number of geomorphology and geodetic techniques were used to better understand the
fault. An analysis of topographic data revealed a sharp discontinuity in slope aspect and
hanging wall tilting which strongly supports the existence of a normal fault. A GPS survey of
an emergent reef platform which revealed a tilted coral surface also indicates that
deformation has occurred in the region.
An interferometric synthetic aperture radar investigation has also been performed to
establish whether active deformation is occurring on the fault. Ground movements that
could be consistent with inter-seismic strain accumulation have been observed, although the
analysis is restricted by the limited data available. However, a simple fault model suggests
that the deformation is unlikely due to continued crustal stretching. This, in addition to the
lack of footwall uplift in the topography data, suggests that the fault is more likely controlled by a shallow salt layer. However, more work will need to be done in the future to confirm
these findings.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/237291 |
| Date | 07 1900 |
| Creators | Smith, Robert B. |
| Contributors | Jonsson, Sigurjon, Mai, Paul Martin, Schuster, Gerard T., Stewart, Ian |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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