The Bengal-Assam Syntaxis: Geometry and Kinematics of Active Faulting
The East Himalayan Syntaxis has been the site of some of the largest continental earthquakes (Assam, 1950, Mw=8.7; Shillong, 1897, M≈8.5). Although this area is arguably where seismic hazard is greatest in the India/Asia collision zone, active faults are poorly mapped and partitioned slip-rates uncertain. The geometry of the MFT in this part of the Himalayan front is unknown. How the Frontal Himalayan Thrust (MFT) interacts with the Mishmi Thrust, the Shillong thrusts or with Myanmar’s Sagaing strike-slip fault remains unclear.
Using quantitative geomorphology and paleoseismology, we document the surface expression of the thrusts and unravel their seismic behaviour both in India and Bangladesh. In doing so, we will resolve long-standing debates surrounding the sources of these major earthquakes and bring new insights about the complex Bengal Assam tectonic system.
- Earth Observatory of Singapore
Elise Kali, Jerome van der Woerd, and Aktarul Ahsan, Institut de Physique du Globe de Strasbourg, France
Emile Okal, Northwestern University Technology, Evanston, USA
Saurabh Baruah, Northeast Institute of Science, Jorhat, India
Marie Etchebes, Schlumberger, Stavenger, Norway
Swapnamita Choudhury, Wadia Institute, DehraDun, India