Ramees R Mir, Imtiyaz A Parvez, Vinod K Gaur

Shear wave velocity structure, together with Moho depths have been estimated in northwestern Himalaya, Hindu Kush and the Pamirs at a potential resolution of 0.5×0.5 degrees and at 1×1 degrees in the surrounding area, by inverting fundamental mode Rayleigh wave group velocities calculated from regional earthquake (Δ ≤ 2500 km) data, and also from their joint inversions with teleseismic receiver functions at 38 of the 59 broadband stations in the region that provided the data. The results yield the shear-wave velocity structure of northwestern Himalaya extending from Hindu Kush through Kohistan-Nanga Parbat to Kashmir Himalaya, as well as the Pamirs in the north and Lesser Himalaya along with the foreland basin including the Hazara syntaxis in the south. In particular, shear-wave velocity profiles illuminate a) the deeper root zone structures of the main geomorphic features, b) a pervasive low velocity layer (Vs ~3.1 km/s) at ~30 km depth beneath the NW Himalaya. Another notable result is the distinctly shallower Moho beneath the Kashmir Himalaya apparently segmented by arc-normal shear zones that cross the rupture zones of the 1905 Kangra and the 2005 Kashmir earthquakes, in turn, marked by the current epoch seismicity. The obtained shear-wave velocity model of the region will be used for precise location of microseismicity, modelling strong ground motion, and as an apriori for future high resolution studies.