The seismic activity of the Sinai subplate region on the basis of both historical (2200 B.C.-1900 A.D.) and recent (1900-1995) earthquake catalogs have been evaluated. Moderate and large earthquakes occurred mainly at the subplate boundaries, Dead Sea Fault (DSF) system in the east, Cyprean arc in the north, and Suez rift in the southwest. Along the Dead Sea Fault system the activity concentrated at the southern and central segments. The earthquake distribution appears to have a tendency to cluster in time and space. The swarms (February, 1983; April, 1990; August, 1993 and November, 1995) in the Gulf of Aqaba indicate that the southern segment of the Dead Sea Fault system is the most seismogenic through the last two decades. North of the Dead Sea depression the seismic activity tends to have occurred with NW trend to extend under the Levantine Sea. Although the northern segment of the Dead Sea Fault system is well defined from geological, geophysical and historical earthquake activity recent seismic activity is practically absent especially north of Latitude 34 N. In the eastern Mediterranean the seismicity is much higher in the area of the Hellenic arc than in the Cyprean arc. Moreover, the activity occurs in a wide belt suggesting that the plate boundary is a deformation zone instead of a single line. The seismic activity in the Gulf of Suez is scattered and does not have any distinct trend. However, three active zones are delineated. At the mouth of the gulf most of activity is concentrated where the Sinai triple junction (Africa, Arabia, Sinai) is situated. The central part and the northern part of the gulf include the adjacent area as far as the river Nile. Actually, the activity is markedly decreased from south to north. Although there is no seismological evidence that the Suez rift continues into the eastern Mediterranean, the activity in the Gulf of Suez region cannot be ignored. The parameters of magnitude-frequency relation (a,b) indicate that the level of earthquake activity in the Sinai subplate region is generally moderate. Moreover, the energy release curve shows a regular trend and reflects occasional high activity.
ASJC Scopus subject areas
- Earth-Surface Processes