Details

Autor(en) / Beteiligte

• Yun-Sheng Yao Qiu-Liang Wang Wu-Lin Liao Li-Fen Zhang Jun-Hua Chen Jing-Gang Li Li Yuan Yan-Nan Zhao

Titel

Influences of the Three Gorges Proiect on seismic activities in the reservoir area

Ist Teil von

• 科学通报：英文版, 2017, Vol.62 (15), p.1089-1098

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Reservoir-induced earthquakes related with the construction of the Three Gorges Project have attracted great concerns of the public. Since the first water impoundment on May 25, 2003, a number of earthquakes have occurred during the water storage stages, in which the largest was the Badong M5.1 earthquake on December 16, 2013. In this paper, the relationships between seismic activities, b value, seismic parameters, and reservoir water level fluctuations are studied. In addition, based on the digital seismic waveform data obtained since 2000, the focal depth changes and focal mechanism characteristics before and after the water impoundment are studied as well. These provide us important information to under- stand the earthquake mechanisms. The results show that these earthquakes are typical reservoir-induced earthquakes, which are closely related to water infiltration, pore pressure, and water level fluctuations. The majority of the micro and small earthquakes are caused by karst collapse, mine collapse, bank reformation, superficial unloading, and so on. The larger earthquakes are related to the fault structures to some extent. Due to the persistent effects of water impoundment on the seismic and geological environ- ments around the reservoir and water infiltration into the rocks, the influences on the crustal deforma- tion field, gravity field, seepage field, and fault medium-softening action may vary gradually from a higher strength to a weaker one. Therefore, it is possible that small earthquakes and few medium earthquakes （M ≤5.5） will occur in the reservoir area in the future.