Estimation of crustal movements along the Nile valley area, Egypt

The Nile Valley in Egypt is located to the west of the Red Sea Rift and to the south of the Mediterranean Sea. Recently, some moderate earthquakes have occurred along the Nile Valley at the eastern and western sides. The major tectonic trends in this area are the NW-SE and NE-SW lineaments. The Nile valley and the Nile delta are a part of the active rift that is probably connected with the Red and Mediterranean seas tectonic activity. This zone is characterized by small-to-moderate intensity earthquakes that have caused extremely severe damage to recent and historical constructions. Small local and large distant earthquakes could be a source of huge socio-economic damage in this area. A program of researching of recent crustal movements in Egypt has been started since 1984 to cover some areas which are characterized by high occurrence of earthquakes. One of these areas is Nile Valley. Several moderate earthquakes with magnitudes more than 4 occurred on both sides of River Nile. The present study aims to determine the recent crustal movement parameters along the Nile Valley using the Global Positioning System (GPS) measurements. To achieve this mission, a GPS network consisting of ten geodetic stations has been established on both sides along the Nile Valley area. GPS measurements have been collected from 2007 to 2012. The result of the data analysis indicates that the rate of local velocity is ranging from 1 to 4 mm per year. This rate is consistent with the occurrence of recent earthquake activity along the Nile Valley area. But the results obtained from GPS stations inclusive of the African Plate regional velocity indicate that the velocity motion is about 25 mm/year taking the northeast direction.