Evaluation of recent crustal deformation and seismicity in spillway fault area, Aswan, Egypt

ABSTRACT The High Dam is a strategic and vital installation because it is considered as the water strategic tool for Egypt. The dam plays vital role in mitigating risks of water shortages and floods. The body of the High Dam established on the basement Granite. The area around High Dam is suffering from seismic activities starting from the famous earthquake of 14 November 1981 (5.6 ML) southwest of the High Dam. On 7 November 2010, earthquake of magnitude 4.6 ML occurred at Spillway fault. Spillway fault is NNW-SSE trend. The fault was plotted by the High and Aswan Dams Authority and Soviet geologists as a normal fault. The fault is exposed as vertical on the cross section, but perhaps dips steeply to the west. This work is trying to study the stability of the area and its relation to the dams as well as estimating the horizontal displacements. For monitoring the horizontal movements, a local geodetic network consisting of 11 geodetic stations was established. A geodetic results showed a post-seismic deformation zone between the High Dam and Aswan Dam that resulted from 7 November 2010 earthquake occurring at Spillway fault and a distance of 4.5 km northwest the High Dam.