Seismicity and water level variations in the Lake Aswan area in Egypt 1982–1997

The data described here are obtained from the continuous record of earthquakeactivity and lake water-level variation in the Lake Aswan area in Egypt between 1982 and 1997. The seismicity is monitored by a local telemetered seismograph network. The hypocentral parameters of earthquakes have been determined using Hypo71. The earthquake foci are distributed in two seismic zones, shallow and deep in the crust. Shallow events have focal depths of less than 10 km. Deep events extend from 10 to 30 km. The temporal sequence of seismicity iscorrelated with both the water-level variation and the average daily change of the water level in the lake Aswan. The temporal variation of the seismicityindicates that there are only six sequences of increased seismic activity during 1982–1997. The correlation between the seismic activity and the daily variation of the lake water level is poorly observed except with the June 1987 events swarm, which was accompanied by the presence of an anomaly in rate of water level decreasing. It is concluded that the increase in seismic activity in the Aswan reservoir is demonstrating an example of rapid reservoir-triggered seismicity. The deeper seismic sequence in this area, which was associated with the November 14, 1981 mainshock (M_D = 5.7), and the earlier seismicity (1981–82), has been correlated with a deeper high velocity anomaly (Awad and Mizoue, 1995-b).