Plate Motion of India and Interseismic Strain in the Nepal Himalaya from GPS and DORIS Measurements

Intraplate deformation of the Indian subcontinent

“…GPS velocities of India. (a) Map showing GPS velocities in India plate reference frame (tipped with 68% confidence ellipses) and derived principal strain axes and magnitudes using a distance-weighted strain interpolation approach [Shen et al, 1996] [Bettinelli et al, 2006;Feldl and Bilham, 2006;Larson et al, 1999] (Figure 2). The distribution and magnitude of contraction centered near the Greater Himalaya do not change appreciably along much of the Himalaya from northwestern India to eastern Nepal (Figure 2).…”

“…Coseismic corrections estimated from the position time series [Banerjee et al, 2005] were applied to the Indian continuous GPS sites to remove the coseismic offsets from the 26th December, 2004 Sumatra-Andaman earthquake (Mw = 9.2). GPS velocities available from other published sources in the region [Bettinelli et al, 2006;Chen et al, 2000;Gan et al, 2007;Jade et al, 2007;Kogan and Steblov, 2008;Sol et al, 2007;Zhang et al, 2004] were combined with our own processed solutions using a 6-parameter Helmert transformation. An India reference frame is established by determining plate rotation parameters that minimize the velocities of 12 stations (10 continuous and 2 survey-mode GPS sites) well within the plate interior (see auxiliary material for details on sites used for the frame realization).…”

Present‐day crustal thinning in the southern and northern Tibetan Plateau revealed by GPS measurements

“…The data set of He et al [2013] contains 16 campaign-mode sites located in a localized dense network across central segment of Altyn Tagh Fault from the Tarim Basin to northern Tibet and measured twice in the period of 2009-2011. In addition, we show published velocities for surrounding regions (Figure 1): from the Nepal Himalaya [e.g., Banerjee et al, 2008;Bettinelli et al, 2006;Bilham et al, 1997;Feldl and Bilham, 2006], northwest Himalaya [Banerjee and Bürgmann, 2002], Pamir-Hindu Kush [Ischuk et al, 2013;Mohadjer et al, 2010], Kashmir and Ladakh Himalaya [e.g., Jade et al, 2004;Schiffman et al, 2013], eastern Himalaya, Naga Hills, and Shillong Plateau [Devachandra et al, 2014;Vernant et al, 2014].…”

“…Although coverage is sparse in some parts of Tibet (Figure 1), GPS velocities, however, can be used to infer strain rates across the region, and we exploit them here to make such a comparison. confidence ellipses), including some data from other published sources, e.g., Tien Shan [Zubovich et al, 2010], Pamir and Hindu Kush regions [Ischuk et al, 2013;Mohadjer et al, 2010], Himalaya [Ader et al, 2012;Banerjee and Bürgmann, 2002;Banerjee et al, 2008;Bettinelli et al, 2006;Jouanne et al, 2014;Schiffman et al, 2013], and Myanmar [Devachandra et al, 2014;Gahalaut et al, 2013;Maurin et al, 2010]. The India-Eurasia rotation pole for an India plate reference frame with respect to Eurasia lies at 27.46°N…”

Constraints on Source Parameters of the 25 April 2015, M_w = 7.8 Gorkha, Nepal Earthquake from Synthetic Aperture Radar Interferometry

“…MHT flattens beneath the Lesser Himalaya and forms a mid-crustal ramp at the front of the Higher Himalaya 14 . During the active thrusting of India under the Tibetan Plateau, MHT is known to absorb about 20 mm/yr convergence in Nepal, which is nearly half the present convergence rate between India and Eurasia [15][16][17][18] . The elastic strain energy thus stored during the interseismic period is released periodically due to earthquakes causing rupture along the interseismically locked, brittle upper part of the MHT system beneath the outer and lesser Himalaya, which is characterized by a southern frontal ramp (MFT) 6,7,19,20 .…”