Overview
- A 5.1-magnitude earthquake hit Upper Siang district early Thursday at 5:45 a.m., with the National Center for Seismology reporting an 11 km depth and an epicentre at 29.124°N, 94.856°E about 116 km north-northwest of Pangin.
- The mainshock was preceded by three shallow foreshocks (magnitudes 2.8, 3.2, 2.8) between about 3:40 a.m. and 4:34 a.m. and followed by a 3.5-magnitude aftershock at 7:17 a.m., forming a multi-hour seismic swarm.
- No immediate deaths or property damage were reported by officials in initial checks, and local authorities have said they will continue monitoring the affected area for further activity.
- Arunachal Pradesh lies in Seismic Zone V along the active Eastern Himalayan plate boundary, which makes shallow quakes more likely and can produce stronger local shaking even at moderate magnitudes.
- Because the district is remote, damage assessments and communications can lag so officials are checking infrastructure and public safety and residents are urged to report damage and follow official guidance.