An earthquake of 5.1 magnitude struck the Upper Siang district early Thursday, 6 August, according to the National Centre for Seismology (NCS). The main shock occurred at 5:45 am, at a depth of 11 kilometres, with its epicentre located 116 kilometres north‑northwest of Pangin (latitude 29.124° N, longitude 94.856° E). No immediate loss of life or property damage was reported.
The main event was preceded by a sequence of three minor foreshocks in the early hours. A 2.8‑magnitude tremor struck at 3:40 am at a depth of 5 km, followed by a 3.2‑magnitude quake at 3:55 am and another 2.8 event at 4:34 am. After the main tremor, a 3.5‑magnitude aftershock was recorded at 7:17 am, also at a depth of 5 km, completing a multi‑hour seismic swarm.
Arunachal Pradesh and the wider Northeast region fall under Seismic Zone V, making the area highly susceptible to tectonic activity due to the complex fault systems under the Eastern Himalayas.
