Fielding, E.J., Sladen, A., Li, Z., Avouac, J.-P., Burgmann, R. and Ryder, I. (2013) Kinematic fault slip evolution source models of the 2008 M7.9 Wenchuan earthquake in China from SAR interferometry, GPS and teleseismic analysis and implications for Longmen Shan tectonics. Geophysical Journal International, 194(2), pp. 1138-1166. (doi: 10.1093/gji/ggt155)
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Abstract
The Mw 7.9 2008 Wenchuan earthquake ruptured about 280 km of faults in the Longmen Shan of Sichuan province, China, at the eastern edge of the Tibetan Plateau. We use teleseismic waveforms with geodetic data from Global Positioning System, synthetic aperture radar interferometry and image amplitude correlation to produce a source model of this earthquake. The model describes evolution of fault slip during the earthquake. The geodetic data constrains the spatial distribution of fault slip and the seismic waveforms constrain mostly the time evolution of slip. We find that the earthquake started with largely thrust motion on an imbricate system of faults beneath the central Longmen Shan, including the Beichuan Fault and Pengguan Fault, with fault slip at depth extending up to 50 km northwest of the mountain front. The fault ruptures continued northeast along the Beichuan Fault with more oblique slip (right-lateral and thrust) and the proportion of lateral motion increasing in the northern Longmen Shan. The northernmost fault segment has a much steeper dip, consistent with nearly pure strike-slip motion. The kinematic source model shows that the rupture propagated to the northeast at about 2.5–3.0 km s−1, producing a cascade of subevents with a total duration of about 110 s. The complex fault ruptures caused shortening and uplift of the extremely steep central Longmen Shan, which supports models where the steep edge of the plateau is formed by thrusting over the strong crust of the Sichuan Basin.
| Item Type: | Articles |
|---|---|
| Status: | Published |
| Refereed: | Yes |
| Glasgow Author(s) Enlighten ID: | Li, Dr Zhenhong |
| Authors: | Fielding, E.J., Sladen, A., Li, Z., Avouac, J.-P., Burgmann, R., and Ryder, I. |
| Subjects: | G Geography. Anthropology. Recreation > G Geography (General) G Geography. Anthropology. Recreation > GB Physical geography Q Science > QE Geology |
| College/School: | College of Science and Engineering > School of Geographical and Earth Sciences > Earth Sciences |
| Journal Name: | Geophysical Journal International |
| Publisher: | Oxford University Press on behalf of The Royal Astronomical Society |
| ISSN: | 0956-540X |
| ISSN (Online): | 1365-246X |
| Published Online: | 22 May 2013 |
| Copyright Holders: | Copyright © 2013 The Authors |
| First Published: | First published in Geophysical Journal International 194(2):1138-1166 |
| Publisher Policy: | Reproduced in accordance with the copyright policy of the publisher |
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