Accurate location and focal mechanism of small earthquakes near Idukki Reservoir, Kerala: implication for earthquake genesis

作者：Saikia Utpal^*; Rai S S; Subrahmanyam M; Dutta Satyajit; Bose Somasish; Borah Kajaljyoti; Meena Rishikesh

来源：Current Science, 2014, 107(11): 1885-1891.

• Earthquake location
• fault plane solution
• reservoir
• tectonics

Earthquake waveform from a new temporary network of 21 seismic stations in South India has been used to significantly improve the detection threshold and parameters of small earthquakes near Idukki Reservoir, Kerala. We present here precise location of 16 earthquakes in this region with a local magnitude of 1.5-3.6 and focal depth 7.2-9.9 km. Fault plane solutions of the selected best six earthquakes show strike-slip faulting and right lateral movement. Reservoir loading usually leads to generation of stress and therefore earthquakes in the shallow depth (<5 km), that are absent in the region of Idukki Reservoir. Recorded earthquakes are confined to a NW-SE trending fault close to Karur-Kamabam-Painavu-Trichur (KKPT) shear zone. These observations suggest that the earthquakes in Idukki region are tectonic in nature and have no linkage with the reservoir.

• 出版日期2014-12-10