Geodetic Evidence of High Compression Across Seismically Active Kachchh Paleorift India

Vineet K. Gahalaut , Kalpna Gahalaut, Rakesh K. Dumka, Pallabi Chaudhury, and Rajeev K. Yadav

Our understanding of occurrence of earthquakes in the plate interior regions is very limited due to their rarity and the slow and complex geodynamic process involved in strain accumulation. Majority of these earthquakes occur in the paleo (or failed or aborted) rift regions. In the present article we report GPS measurements of deformation rate across the Kachchh paleorift, which has witnessed several major earthquakes in the past 200 years, the most recent being the 2001 Bhuj earthquake (Mw 7.6). Immediately after the earthquake the deformation in the vicinity of the earthquake rupture was considered to be occurring in response to the viscoelastic relaxation of the upper mantle, which decayed rapidly due to weak upper mantle rheology. Our new continuous GPS measurements of past 7 years across the paleorift are inconsistent with the models of postseismic deformation. These measurements suggest high regional compression across the Kachchh paleorift, which explain the high seismicity in the region.



GPS measurements of crustal deformation (2006/2009–2016) from the Kachchh and adjoining region

Tectonics, 38, 3097–3107. 2019TC005496