Geodetic evidence for a low slip rate in the Altyn Tagh fault system

Abstract

The collision between India and Asia has been simulated with a variety of computational models that describe or predict the motions of the main faults of east Asia. Geological slip-rate estimates of 20-30 mm yr(-1) suggest that the largest of these faults, the 2,000-km-long Altyn Tagh fault system on the northern edge of the Tibetan plateau, absorbs as much of the Indo-Asian convergence signal as do the Himalayas--partly by oblique slip and partly by contraction and mountain growth. However, the predictions of dynamic models for Asian deformation and the lower bounds of some geological slip-rates estimates (3-9 mm yr(-1); refs 7, 8) suggest that the Altyn Tagh system is less active. Here, we report geodetic data from 89-91 degrees E that indicate left-lateral shear of 9 +/- 5 mm yr(-1) and contraction of 3 +/- 1 mm yr(-1) across the Altyn Tagh system. This result--combined with our finding that, at 90 degrees E, Tibet contracts north-south at 9 +/- 1 mm yr(-1)--supports the predictions of dynamic models of Asian deformation.

Interseismic Deformation of the Altyn Tagh Fault Determined by Interferometric Synthetic Aperture Radar (InSAR) Measurements

“…Late Quaternary slip rates have been reported along most of the ATF at both decadal and millennial time scales. Geodetic measurements at the decadal time scale indicating that the ATF slips at~10 mm/year [12][13][14][15] have been used to support continuum deformation of the Tibetan Plateau [1,2,8,15] or block-like deformation [3,4]. Elliott et al [16] investigated the same location as this study using ERS data and the stacking method and concluded that the slip rate was 11˘5 mm/year, Remote Sens.…”

Inference of Multiple Earthquake-Cycle Relaxation Timescales from Irregular Geodetic Sampling of Interseismic Deformation

“…Johnson and Segall (2004) also extended the Savage and Prescott (1978) model to include the localized creep on a linear viscous shear zone within the upper elastic layer. Geographic distribution of the 15 strike-slip faults considered in this study: (1) Alpine, (2) Altyn Tagh, (3) Dead Sea, (4) Elsinore, (5) Fairweather, (6) Garlock, (7) Karakoram, (8) SAF-Mojave, (9) North Anatolian, (10) Owens Valley, (11) Philippine, (12) SAF-Carrizo, (13) SAF-Indio, (14) San Jacinto, and (15) Haiyuan (Sharp, 1967(Sharp, , 1981Savage and Burford, 1973;Plafker et al, 1978;Sieh and Jahns, 1984;Lubetkin and Clark, 1988;Rockwell et al, 1990;Barrier et al, 1991;Lisowski et al, 1991;Merifield et al, 1991;McGill and Sieh, 1993;Beanland and Clark, 1994;Duquesnoy et al, 1994;Petersen and Wesnousky, 1994;Bennett et al, 1996Bennett et al, , 1997Armijo et al, 1999;Beavan et al, 1999;Lasserre et al, 1999;Bendick et al, 2000;Klinger et al, 2000;Reilinger et al, 2000;Argus and Gordon, 2001;Lee et al, 2001;Miller et al, 2001;Niemi et al, 2001;Norris and Cooper, 2001;Banerjee and Bürgmann, 2002;Brown et al, 2002;Hubert-Ferrari et al, 2002;Fletcher and Freymueller, 2003;Meghraoui et al, 2003;Lacassin et al, 2004;…”

Crustal–lithospheric structure and continental extrusion of Tibet

“…They are either used to directly calculate a rate based upon a profile across the fault (Bendick et al 2000) or used in larger plateau-wide studies Gan et al 2007). Additionally, they are used in block or continuum models for the plateau (e.g.…”

“…Zhang et al 2004;Gan et al 2007), and are determined from fitting the horizontal velocities to a locked fault elastic model. The first GPS measurement for the Altyn Tagh was made by Bendick et al (2000) and consisted of a transect of GPS observations on the east-central portion of the fault and the North Altyn Tagh Fault. The result pointed towards a low slip rate of 4-14 mm a À1 (as well as a small convergent component of 2-4 mm a À1 ).…”