Seasonal trends and relation to water level of reservoir-triggered seismicity in Song Tranh 2 reservoir, Vietnam

Reservoir-triggered seismicity (RTS) has the potential to generate disastrous seismic events of M6 and bigger. Song Tranh 2 (STR2) is an artificial water reservoir located in Central Vietnam. High activity been observed this area since was first filled 2011. The relation between level complex, previous studies have led conclusion that ongoing STR2 example delayed response type RTS. However, phase after impoundment deemed a rapid type. There were three stages filling periods: first, period initial impoundment, hereinafter referred as pre-gap (from 05/01/2011 10/06/2012), then gap 10/06/2012 31/08/2013) where stopped drained minimum exploitation level, finally, third post-gap 31/08/2013 19/06/2017). In work, we prove results 2-fold rise rate. re-filling drop rate, roughly equal period, accompanied by significant increase b-value. As consequence, gap, exceedance probability significantly lower comparison periods. We also proved recorded 2013 2016 manifested seasonal trends related changes during wet dry seasons. its delay with respect suggest main triggering factor pore pressure change due observed. findings indicate load considerably influence stress orientation area.