Research Projects

The 2021 Assam earthquake (Mw 6.4) and 2023 Turkey earthquake (Mw 7.8) re-emphasized the importance of improved understanding of the active fault systems of a region, as an earthquake along these faults may cause tremendous damage to infrastructure and human population residing in those areas. In order to minimize the damage in any particular region, there is a vital need to carry out the seismic vulnerability assessment which requires seismotectonic study of the areas and compilation of past earthquake events i.e palaeo-earthquakes that have occurred during the recent past. The northeastern Himalaya has been experienced very large to great earthquakes. For example, year 1947 Arunachal Pradesh EQ (Mw 7.7), 1950 Assam EQ (Mw 8.7), 1988 Manipur EQ (Mw 7.3), 2009 Assam EQ (Mw 5.1), 2011 Sikkim EQ (Mw 6.9), 2016 Imphal EQ (Mw 6.7), 2021 Assam EQ (Mw 6.4) (Baro and Kumar, 2017; Joshi et al., 2023). Similarly the Shillong Plateau also experienced the earthquakes such as the 1897 great earthquake (Mw=8.1); 10 January 1869 (Mw 7.3), 8 July 1918 (Mw 7.1), 9 September 1923 (Mw 7.1), 3 July 1930 (Mw 7.1) and 23 October 1943 (Mw 7.1) (Dasgupta, 2011). The Holocene earthquake history of Shillong plateau is less studied (Sukhija et al., 1999; Rajendran et al., 2004). Several fault systems encircle the plateau on all sides. Dauki Fault (DF) at South, Brahmaputra Fault (BF) and Oldham Fault (OF) in the north, Naga–Disang Thrust (Schuppen Belt) and sinistral strike slip Kopili Fault in east and Dhubri Fault mark the western margin of the plateau. All these fault system makes Shillong Plateau tectonically alive. There are only few studies highlighting the occurrence of palaeoearthquakes in Shillong plateau which is of vital importance for seismic hazard assessment and vulnerability planning (Sukhija et al., 1999; Rajendran et al., 2004). In order to understand the impact of different natural hazard on the socio-economic fabric in Shillong region, a questionnaire-based survey and geological study were conducted by PI (Mayank Joshi) under a NMHS funded project. The people of all wards experienced earthquakes in regular interval and unaware about the mitigation measures from earthquake. In that project, the PI has already identified several sites which preserve the signatures of active faulting. The preliminary field visit also showed that some houses built in slopes which are prone to earthquake induced landslides. Therefore, the present proposed study is very essential to study the tectonically active segments of Shillong plateau and to understand the palaeo-earthquake history of the region to minimize the effects of seismic hazards. The study also aims to significantly contribute to the ongoing hot debate on assessing responsible fault for 1897 Shillong Earthquake. This project also helps to enrich the active faults database of this segment of India, which is a vital and densely populated region of the northeast India.