Abstract:We analyze the seismicity characteristics of Xiangjiaba reservoir region before and after the impoundment, as well as the relationship between the seismic sequence in the last segment and the reservoir water level, combined with the lithological and structural features of the epicenter area. We find that the earthquakes occurred in the last segment of Xiangjiaba reservoir are structural reservoir-induced earthquakes. These earthquakes are distributed in a NW direction. Although no obvious surface rupture zones are formed, there may be hidden faults 2 km below the surface. This area is located in the middle section of the Mabian-Yanjin fault zone, and shows very low levels of natural seismic activity prior to the impoundment of reservoir. However, after impoundment, the frequency and intensity of seismicity increased in this area.
YANG Lei,LI Baohua,CHANG Tinggai. Seismicity Characteristics of Xiangjiaba Reservoir Region before and after the Impoundment[J]. jgg, 2019, 39(9): 919-923.