An earthquake measuring 5.1 on the Richter scale struck Upper Siang district in Arunachal Pradesh early Thursday, according to the National Centre for Seismology (NCS). The main shock occurred at 5:45 a.m. local time and was felt at a depth of 11 kilometres.
Officials reported no immediate loss of life or damage to property following the tremor.
The main event was preceded by a series of three smaller foreshocks in the early hours. A magnitude 2.8 quake struck at 3:40 a.m. at a depth of 5 kilometres, followed by a magnitude 3.2 shock at 3:55 a.m. and another magnitude 2.8 tremor at 4:34 a.m. After the mainshock, a magnitude 3.5 aftershock was recorded at 7:17 a.m., also at a depth of 5 kilometres, completing a multi‑hour seismic swarm.
The epicentre of the 5.1 quake was located 116 kilometres north‑north‑west of Pangin, at latitude 29.124° N and longitude 94.856° E. Arunachal Pradesh and the broader Northeast region lie in Seismic Zone V, making them highly susceptible to tectonic activity due to the complex fault systems beneath the Eastern Himalayas.
