Detection of the submerged topography along the Egyptian Red Sea Coast using bathymetry and GIS-based analysis

Abstract

A long time ago the Red Sea was only known by small-scale bathymetric, magnetic anomaly maps and a few seismic reflection or refraction profiles. Therefore, detection of the major submerged coastal features was unattainable. This study is based on the integration of different data sets of topography and bathymetry (e.g. the global bathymetry data set, the SRTM DTED® 2, the soviet military topographic maps of scale 1:200.000 and the US army topographic maps of scale 1:250.000) to reveal the main submarine landforms that marked the continental shelf and its related slopes along the Egyptian Red Sea Coast from latitude 27°43′N to the Egyptian-Sudanese border at latitude 22°00′N. The study deduced that the continental shelf is noticeably influenced by the surface fault system extending eastward into the main Red Sea depression, showing the continental edge mostly like a fault-scarp of ∼60° anticlockwise fault plane. Sea ridges and subbasins were distinguished at the lower toe of the continental slope, which seem to be a result of a regional fold system. Two sea peaks of extinct volcanoes were recognized. Two types of submarine canyons were recognized as deep incised Messinian canyons and shallow canyons. The deep incised canyons (∼500mbsl) carve the continental edge with remarkable steep walls. They might be formed as a result of the Messinian event (∼5.59Ma). The shallow canyons are mostly developed during the Pleistocene lower sea level (∼90–130mbsl) where the major wadis cut their water courses through the continental shelf. Some individual submerged deltas were identified, showing a close relationship with the present-day drainage system, although they were supposed to be produced by an ancestor drainage system. Notable submarine terraces were recognized at depths 20–25, 50–75, and 100–120mbsl that are in agreement with the generalized global curve of sea-level rise since the LGM (∼23–18ka bp). It is expected that results of this study will be helpful for shedding light on the geomorphologic evolution of the continental shelf and its surrounding landmass.