T182 Kinematics of the Himalayan-Tibetan Orogen—Comparing the Present with the Past
Tuesday, 29 October 2002
1:30 PM - 5:30 PM
INTEGRATING INSAR AND GEOLOGIC ESTIMATES OF SLIP RATES IN CENTRAL TIBET
Paper number: T182-11
Program: Technical Sessions
Time: 4:10 PM – 4:25 PM
Authors
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Gilles PeltzerUCLA, Los Angeles, CA
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An YinUCLA, Los Angeles, CA
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F.J. RyersonLawerence Livermore National Laboratory, Livermore, CA
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Robert FinkelLawerence Livermore National Lab, Livermore, CA
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Lin DingChinese Academy of Sciences, Beijing, N/A
Abstract
We use a combination of repeat-pass synthetic aperture radar interferometry (InSAR) and cosmogenic dating to characterize the slip-history along the Dong Co conjugate fault system in Central Tibet. The Dong Co conjugate fault system is centered along the E-trending Bangong-Nujiang suture zone. The conjugate fault system is comprised of the NE-striking left-slip Riganpei Co fault to the north and NW-striking right-slip Gyaring Co fault to the south. These structures accommodate a portion of Indo-Asian convergence and long term slip-rates determined along these faults indicate north-south contraction is occurring across Central Tibet at a rate of ~2 mm/yr. Preliminary interferograms were constructed using descending orbital tracks of the ERS 1 and ERS 2 European Space Agency satellites with a time-span of seven years. Surface displacement maps along the radar line of sight indicate a significant strain gradient from the NW to SE centered along the Riganpei Co fault, and is consistent with left-slip. Our preliminary InSAR results are consistent with geologic observations and suggest little variation in the near-field strain rate since about 7 ka.