Himalayan Geology, Vol. 44 (2), 2023, pp. 57-63, Printed in India

Possible implications of recent Doti-Nepal earthquake (M 6.3) for seismicity monitoring in the Central Himalaya

ANIL TIWARI, PARVEEN KUMAR, KALACHAND SAIN*, AJAY PAUL

Wadia Institute of Himalayan Geology, Dehradun, India

*Email (Corresponding author): kalachandsain7@gmail.com

Abstract: During the last few decades, there have not been any great earthquake in the Indian Himalayan region between two epicentre zones of 1934 Bihar-Nepal earthquake (M 8.4) and 1905 Kangra earthquake (M 7.8). However, in-between the central part of the Himalaya experienced several significant earthquakes: 1991 Uttarkashi earthquake (M 6.8), 1999 Chamoli earthquake (M 6.6), 2015 Gorkha earthquakes (M 7.8 and M 7.3), 2017 Chamoli-Rudraprayag earthquake (M 5.7), 2022 Doti-Nepal earthquake (M 6.3) and 2023 Jumla-Nepal earthquake (M 5.6). We have estimated the stress drop values associated with the recent strong Doti-Nepal earthquake and moderate Jumla-Nepal earthquake and compared them with the significant Himalayan ruptures and their stress drops. The attributes of fault plane solution of Doti-Nepal earthquake along the rupture is in agreement with the Himalayan compressive tectonic setting. Region having significant ruptures and their stress drops i.e. regions affected by strong to major earthquakes, indicate high stress accumulation zones for future significant ruptures near rigid lithological tectonic setting. Furthermore, the study shows the development of subsurface weak zones in the central Himalaya due to frequent release of stress drop over the last three decades, which might either delay the occurrence of an envisaged major/great earthquake or advance the same with lower side of magnitude.

Keywords: Central Himalaya, Earthquakes, Stress drop, Fault plane solution