2021 Assam earthquake
The 2021 Assam earthquake struck 11 km away from Dhekiajuli, Assam, India at 07:51 (IST) on April 28, 2021 with a moment magnitude of 6.0 at depth. The quake struck with an epicenter 140 km north of the main city of Guwahati. It resulted in two fatalities and at least 12 injuries.
Tectonic setting
The tectonics of the Assam region is dominated by convergence of the India, Burma and Eurasian plates. Major fault structures like the Main Frontal Thrust, Main Boundary Thrust and Main Central Thrust, all splay branches of the Main Himalayan Thrust, accommodate the shortening rate as India is pushing into Asia. The large 8.6 Assam–Tibet earthquake in 1950 was a megathrust earthquake that resulted from a rupture along the Main Himalayan Thrust and Main Frontal Thrust.Earthquake
The earthquake occurred as a result of oblique-slip faulting at a shallow depth just at the foothills of the Himalayas. Analysis by India's National Centre for Seismology revealed that the earthquake involved slip along the Kopili Fault, near the Main Frontal Thrust. This is a northeast striking fault structure that runs from east of the Shillong Plateau, through the Assam Valley and into Bhutan for a total estimated length of 300 km, and a width of 30 km. Its predominant slip sense is right-lateral strike-slip.The same fault is believed to have caused an 6.1 earthquake in Bhutan in 2009, killing 11 and injuring dozens. Two other 7.0+ earthquakes rocked the Assam Valley in 1869 and 1943, is believed to have been on this fault, as well as the deadly 2016 Imphal earthquake on its southern termination.