GPS-derived deformation rates in northwestern Himalaya and Ladakh

Abstract

Deformation rates derived from GPS measurements made at two continuously operating stations at Leh (34.1°N, 77.6°E) and Hanle (32.7°N, 78.9°E), and eight campaign sites in the trans-Himalayan Ladakh spanning 11 years (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008), provide a clear picture of the kinematics of this region as well as the convergence rate across northwestern Himalaya. All the Ladakh sites move 32-34 mm/year NE in the ITRF2005 reference frame, and their relative velocities are 13-16 mm/year SW in the Indian reference frame and *19 mm/year W with reference to the Lhasa IGS station in southeastern Tibet. The results indicate that there is no statistically significant deformation in the 200-km stretch between the continuous sites Leh and Hanle as well as between Leh and Nubra valley sites along the Karakoram fault, whereas the sites in and around the splayed Karakoram fault region indicate surface deformation of 2.5 mm/year. Campaign sites along the Karakoram fault zone indicate a fault parallel surface motion of 1.4-2.5 mm/year in the Tangste and western Panamik segment of the Karakoram fault, which quantifies the best possible GPS-derived dextral slip rate of 3 mm/ year along this fault during this 11-year period. Baselines of Ladakh sites show convergence rates of 15-18 mm/year with respect to south India and 12-15 mm/year with respect to Delhi in north India and Almora in the Himalaya *400 km north-northeast of Delhi. These constitute an arc normal convergence of 12-15 mm/year across the western Himalaya, which is consistent with arc normal convergence all along the Himalayan arc from west to east. Baseline extension rates of 14-16 mm/year between Lhasa and Ladakh sites are consistent with the east-west extension rate of Tibetan Plateau.

Thermochronologic constraints on the late Cenozoic exhumation history of the Gurla Mandhata metamorphic core complex, Southwestern Tibet

“…The mean modeled slip rates in this study match slip rate estimates for the southern KF across different timescales (Figure ). Some of the best rate agreements are with the geodetic loading rates [ Chen et al ., ; Wright et al ., ; Zhang et al ., ; Jade et al ., , ; Loveless and Meade , ] and the slower, long‐term fault slip rates [ Murphy et al ., ; Phillips et al ., ; Rutter et al ., ; Wang et al ., ], while only a single slip rate using cosmogenic nuclides is in agreement with our mean modeled fault slip rate (Figure ) [ Brown et al ., ]. The individual transect results show that the fault slip rates obtained for the northern transect match all of the KF slip rate data, but this is mostly due to the very high fault slip rate associated with initiation of the GMD.…”

“…[]; J10 ‐ Jade et al . [, ]; L4 ‐ Lacassin et al . []; L11 ‐ Loveless and Meade []; M0 ‐ Murphy et al .…”

Spatial variation in exhumation rates across Ladakh and the Karakoram: New apatite fission track data from the Eastern Karakoram, NW India

“…In the other, the fault has accommodated offsets of less than 150 km at slip rates of <10 mm/yr, initiating after 15.68 ± 0.5 Ma [Phillips et al, 2004;Searle, 1996;Searle and Phillips, 2007;Searle et al, 1998Searle et al, , 2011Wallis et al, 2014aWallis et al, , 2014bWang et al, , 2013Zhang et al, 2011]. Estimates of both the Quaternary and present-day slip rates of the KFZ span 0-11 mm/yr [Banerjee and Bürgmann, 2002;Brown et al, 2002;Chevalier et al, 2012;Jade et al, 2004Jade et al, , 2010Robinson, 2009;Wang and Wright, 2012]. Paleoseismic evidence suggests that large earthquakes have occurred on both the Nubra (M w > 6) and Pangong (M w 7-8) strands of the fault during the Quaternary [Brown et al, 2002;Phartiyal and Sharma, 2009;Phartiyal et al, 2005;Upadhyay, 2001Upadhyay, , 2003.…”

Postglacial denudation of western Tibetan Plateau margin outpaced by long-term exhumation

“…Basinwide denudation rates upstream of the Leh valley and downstream of Khalsi, i.e., beyond the infl uence of the Choksti fault, are indistinguishable on both Indus valley fl anks. However, evidence for neotectonic activity remains elusive (Burbank and Fort, 1985), and recent global positioning system measurement data show no statistically signifi cant deformation between the nearest stations of Leh and Hanle (Jade et al, 2010). Although neotectonics cannot be discarded fully as a possible control (Searle et al, 1990;Sinclair and Jaffey, 2001), any evidence to support the regional denudational asymmetry between the upper and the lower bedrock gorges on at least postglacial time scales remains to be found by fi eld work, satellite imagery analysis, or morphometric DEM analysis.…”