Statistical investigation of reservoir-induced seismicity in Aswan area, Egypt

The purpose of this study is to understand the effect of the fluctuation of the water level in Lake Nasser on the seismicity in the Aswan area, Egypt. Two statistical methods have been applied using the sequence of seismic events between 1982-1998 with local magnitude m ≥ 2.0, recorded by the Aswan Regional Seismological Center in Egypt. Firstly, a cross-correlation method is adopted to find the relationship between the water level and the seismicity. A maximum correlation coefficient of +0.55 was obtained for the period (1982-1985) at a 60 days time lag. However, coefficients are very small for other periods. Secondly, a point-process procedure is applied to the seismicity for the period (1992-1998), where a hazard function includes a term presenting reservoir-induced seismicity. This analysis confirms a weak relation between the fluctuation of the water level and the seismicity in the area. The result suggests that the seismicity in the area becomes active during a period when the water level is decreasing from the maximum to the minimum.