4. The influence of Aswan Reservoir Loading on Earthquake Activity
The change in level of any lake is controlled by the difference between the sources of inflow and outflow, compared to the total volume of the lake. One of the factors that have been observed to have a significant effect on the rate of seismicity at reservoirs is the way in which the water level changes in the reservoir [24] and [11]. Variations in filling rate are strongly influenced by the type of utilization of the reservoir, local climatic conditions, and topography. In addition to the importance of water level changes the steady- state utilization of the reservoir, the pattern of reservoir filling from first impoundment to maximum capacity is important in terms of triggered seismicity. Depending on reservoir size, climate, topography, and utilization and construction practices, some reservoir fill rapidly and reach maximum capacity during the first filling cycle, whereas others take many years to fill. Due to the lack of local earthquake data before and during the first stages of the reservoir filling, it was
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5. Water level in the Aswan High Dam reservoir and the number of earthquakes per day during the period from 1982 to 2014
A seismic activity with low magnitude was noticed during the beginning of 1984 accompanied the seasonal gradual decreasing of the water level in the reservoir which reached in some days up to 10 cm/day. Two earthquakes with magnitude 3.5 were recorded, the first occurred on January 10, with magnitude 3.6 while the second occurred on April 11, with magnitude 4. On the other hand, the loading season was with rate 0 ~ 5 cm / day. No earthquakes with magnitude 3.5 were recorded.
In the first half of 1985, the unloading rate was less than 7 cm / day without any obvious seismic activity. The annual increasing rate of the water in the reservoir reached on September 14, to its maximum value, 23 cm / day. No events with magnitude 3.5 accompanied this high rate