Crustal deformation rates in Kashmir valley and adjoining regions from continuous GPS measurements from 2008 to 2019

Abstract

We present GPS velocities in Kashmir valley and adjoining regions from continuous Global Positioning System (cGPS) network during 2008 to 2019. Results indicate total arc normal shortening rates of ~ 14 mm/year across this transect of Himalaya that is comparable to the rates of ~ 10 to 20 mm/year reported else-where in the 2500 km Himalaya Arc. For the first time in Himalayas, arc-parallel extension rate of ~ 7 mm/year was recorded in the Kashmir valley, pointing to oblique deformation. Inverse modeling of the contemporary deformation rates in Kashmir valley indicate oblique slip of ~ 16 mm/year along the decollement with locking depth of ~ 15 km and width of ~ 145 km. This result is consistent with the recorded micro-seismicity and low velocity layer at a depth of 12 to 16 km beneath the Kashmir valley obtained from collocated broadband seismic network. Geodetic strain rates are consistent with the dislocation model and micro-seismic activity, with high strain accumulation (~ 7e−08 maximum compression) to the north of Kashmir valley and south of Zanskar ranges. Assuming the stored energy was fully released during 1555 earthquake, high geodetic strain rate since then and observed micro-seismicity point to probable future large earthquakes of Mw ~ 7.7 in Kashmir seismic gap.

Shear wave velocity structure beneath North-Western Himalaya and adjoining areas

“…Convergence vectors in northwestern Himalaya have been found to be different from those in Central and Nepal Himalaya (Schiffman et al 2013;Jade et al 2020), as might be expected because of its location at the extremity of the arc, close to the Chaman-Herat transform boundary along which India slides northeastward, adding along-arc stresses to those arising from the arcnormal convergence. Schiffman et al (2013) and Jade et al 2020 also determined that the interseismic locked zone in northwestern Himalaya is ~145-150 km wide unlike its 100 km width in central and Nepal Himalaya.…”

“…Convergence vectors in northwestern Himalaya have been found to be different from those in Central and Nepal Himalaya (Schiffman et al 2013;Jade et al 2020), as might be expected because of its location at the extremity of the arc, close to the Chaman-Herat transform boundary along which India slides northeastward, adding along-arc stresses to those arising from the arcnormal convergence. Schiffman et al (2013) and Jade et al 2020 also determined that the interseismic locked zone in northwestern Himalaya is ~145-150 km wide unlike its 100 km width in central and Nepal Himalaya. The work presented here was motivated by the need to obtain high resolution shear velocity structure of the region spanning the northwestern extremity of the Himalaya to serve as a base-map for investigating its finer structure, carved by more complex convergence processes, notably the Moho and intra-crustal features, as well as quantification of the resulting hazard.…”

Imaging subsurface geological complexity (2D/3D) beneath the Greater Srinagar region of the Kashmir basin, Northwest Himalaya

“…2000; Jade et al. 2020) – and regional youth and active faults (e.g., MCT/Panjal, Balapore, Bagh Balakot, Riasi Thrust and Kishtwar Fault) have been delineated using satellite images and mapping of geomorphic features (Thakur et al. 2010; Shah 2013; Ahmad et al.…”

“…1) with high strain accumulation of 7 × 10 −8 maximum compression (Jade et al. 2020) from dense GPS network installed by CSIR‐4PI in the valley.…”

“…2014; Stevan and Avouac 2015; Bilham 2019; and Jade et al. 2020). In contrast to these studies, historical and recent tectonic and climatic activities set up a complex Quaternary sedimentary structure in the Kashmir basin.…”