Coseismic and post-seismic activity associated with the 2008 Mw 6.3 Damxung earthquake, Tibet, constrained by InSAR

Bie, Lidong, Ryder, Isabelle, Nippress, Stuart E.J. and B̈urgmann, Roland (2014) Coseismic and post-seismic activity associated with the 2008 Mw 6.3 Damxung earthquake, Tibet, constrained by InSAR. Geophysical Journal International, 196 (2). pp. 788-803. ISSN 0956-540X

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Abstract

The 2008 Mw 6.3 Damxung earthquake on the Tibetan Plateau is investigated to (i) derive a coseismic slip model in a layered elastic Earth; (ii) reveal the relationship between coseismic slip, afterslip and aftershocks and (iii) place a lower bound on mid/lower crustal viscosity. The fault parameters and coseismic slip model were derived by inversion of Envisat InSAR data. We developed an improved non-linear inversion scheme to find an optimal rupture geometry and slip distribution on a fault in a layered elastic crust. Although the InSAR data for this event cannot distinguish between homogeneous and layered crustal models, the maximum slip of the latter model is smaller and deeper, while the moment release calculated from both models are similar. Ã1.6 yr post-seismic deformation time-series starting 20 d after the main shock reveals localized deformation at the southern part of the fault. Inversions for afterslip indicate three localized slip patches, and the cumulative afterslip moment after 615 d is at least ̃11 per cent of the coseismic moment. The afterslip patches are distributed at different depths along the fault, showing no obvious systematic depth-dependence. The deeper of the three patches, however, shows a slight tendency to migrate to greater depth over time. No linear correlation is found for the temporal evolution of afterslip and aftershocks. Finally, modelling of viscoelastic relaxation in aMaxwell half-space yields a lower bound of 1 × 1018 Pa s on the viscosity of the mid/lower crust. This is consistent with viscosity estimates in other studies of post-seismic deformation across the Tibetan Plateau.

Item Type: Article
Uncontrolled Keywords: asia,earthquake source observations,radar interferometry,rheology: crust and lithosphere,seismic cycle,time-series analysis,geophysics,geochemistry and petrology ,/dk/atira/pure/subjectarea/asjc/1900/1908
Faculty \ School: Faculty of Science > School of Environmental Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 22 Apr 2022 10:30
Last Modified: 14 Jun 2022 11:31
URI: https://ueaeprints.uea.ac.uk/id/eprint/84738
DOI: 10.1093/gji/ggt444

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