Kenyir Lake, situated in Terengganu, Malaysia, is a substantial reservoir formed by the construction of the Kenyir Dam in 1985. The lake is not known for high seismicity, however, seismic activity can still occur in the region, albeit less frequently in areas with lower historical seismicity. This study examines the potential fault reactivation linked to seismic activities in the Kenyir Lake region. Data spanning from 1985 to 2020 from the Malaysia Meteorological Department (MMD) were analysed. A total of 27 tremors were identified between 1985 to 1987, ranging in moment magnitude (Mw) from 2.67 to 4.71. Notably, the Kenyir Dam experienced three local seismic events, with magnitudes of Mw 3.9 in 1985 and 1987, and Mw 1.7 in 2016. The epicenters of these events are closely situated within the Terengganu Fault Zone, exhibiting a sinistral strike-slip fault system over 150 km, characterized by an evident N-S lineament in its northern segment, transitioning into an NNW-SSW trending lineament towards the south. Remarkably, prior to dam construction, no earthquake reports were documented in the region, suggesting a potential correlation between induced seismicity and dam-related activities. The observed induced earthquakes near the Kenyir Dam raise concerns regarding fault reactivation due to increased stress and pore pressure beneath the reservoir from water impoundment. This study emphasizes the importance of risk management strategies, regulations, and continuous monitoring to mitigate induced seismicity risks associated with human activities impacting seismic events in such intraplate settings.

induced seismicity;water impoundment;fault reactivation;microtremor;earthquake