A TECTONIC MODEL AND BOUNDARIES FOR THE SOUTHEASTERN MEDITERRANEAN REGION, INCLUDING NORTHEASTERN PART OF EGYPT, FROM BOUGUER AND SATELLITE ALTIMETRY DATA ANALYSIS

The Eastern Mediterranean region is one of the interested regions from tectonic and seismic point of views. It shows an active tectonic boundaries attributed to the collision of the African and Eurasian plates from one side and the Arabian-Eurasian convergence from the other side. This tectonic setting is attributed with continuous seismological activity, which affects almost all the countries of the eastern Mediterranean including northern Egypt.
According to the results of horizontal gradient (HG) and tilt derivative (TDR) maps, the study area was mainly divided into important four tectonic subzones depending on the estimated basement relief and Moho depth maps. These subzones are distributed from south to the north as: Nile delta-northern Sinai zone, north Egyptian coastal zone, Levantine basin zone and northern thrusting (Cyprus and its surroundings) zone. These zones are separated from each other by horizontal tectonic boundaries and/or near-vertical faults that display the block-faulting tectonic style of this belt.
The horizontal gradient (HG) and tilt derivative (TDR) gravity maps show a number of steep and gentle lineaments. It seems that these lineaments E-W, NE and NW-trending correspond to major structural zones of continental or oceanic crust. Moreover, the prominent Pelusium tectonic mega shear zone was well defined in this study using both HG and 3D density models. This zone is extended in NE direction and well coincided with the continental-oceanic boundary zone of Levantine basin for the western Israeli offshore region. The crustal relief beneath this zone, as indicated from the 3D Bouguer interpretation, shows a poor flattening, which almost resulted from left-lateral movements (Neev et al., 1975). Finally, a plate tectonic map for study area was obtained using the evaluated 3D crustal modeling and tectonic boundary map.
The current study indicates that satellite gravity data is a valuable source of data in understanding the tectonic boundary behavior of the studied region and that satellite gravity data is an important modern source of data in the geodynamical studies.