Microearthquake activity near the Idukki Reservoir, south India: A rare example of renewed triggered seismicity

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• 作者：Kusala Rajendran^a ; ^{kusala@ceas.iisc.ernet.in} ; N. Thulasiraman^a ; K. Sreekumari^b
• 关键词：Reservoir triggered earthquakes ; Idukki Reservoir ; Hydroseismicity ; Earthquake mechanisms
• 刊名：Engineering Geology
• 出版年：2013
• 出版时间：8 February, 2013
• 年：2013
• 卷：153
• 期：Complete
• 页码：45-52
• 全文大小：1296 K

文摘

Earthquakes triggered by artificial reservoirs have been documented for more than seven decades and the processes leading to this phenomenon are fairly well understood. Larger among such earthquakes are known to occur within a few years of reservoir impoundment and usually the activity decreases with time. A documented example of Reservoir Triggered Seismicity (RTS), the Idukki Reservoir in Kerala, south India, impounded in 1975, is an exception wherein the triggered activity has been revived in 2011, nearly 35 years after the initial burst of activity in 1977, two years after the dam was filled. The magnitude of the largest shock in the 2011 sequence exceeded that of the previously documented largest microearthquake. Presence of faults that are close to failure and vulnerable to increase in pore pressure due to reservoir loading or increased rainfall, or a combination of both seems to trigger shocks in this area. The renewed burst of earthquakes after a prolonged period of reduced activity at the Idukki Reservoir is a rare example of RTS.