Crustal fluid and afterslip drive transient postseismic deformation associated with the 2016 Meinong earthquake (Mw 6.4)
Abstract
The 2016 Meinong earthquake (Mw 6.4) occurred in the southern Taiwan, and caused heavy causalities and one building collapse in Tainan city. Here we employ the empirical orthogonal function (EOF) to capture the coherent spatio-temporal features of surface deformation associated with this event in the continuous GPS (cGPS) time series. The solved EOF modes feature the dominant coseismic offsets for three components which are constant with the forward modelling using the seismic dislocation theory, and a significant transient postseismic deformation, which mainly reflect in the E component. There is no clear pre-seismic deformation rate change in the cGPS time series through the Monte Carlo simulation and statistical test based on the time series of mode 1. The effect of the poro-elastic rebound, viscoelastic relaxation of the upper mantle, and the after-slip is combined to explain the observed postseismic deformation. Results show that the viscoelastic relaxation plays a negligible role in the postseismic deformation. Such transient postseismic deformation is dominated by the poro-elastic rebound and possible after-slip, which only lasts few months.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.G43B0743K
- Keywords:
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- 1209 Tectonic deformation;
- GEODESY AND GRAVITY;
- 1525 Paleomagnetism applied to tectonics: regional;
- global;
- GEOMAGNETISM AND PALEOMAGNETISM;
- 3040 Plate tectonics;
- MARINE GEOLOGY AND GEOPHYSICS;
- 7230 Seismicity and tectonics;
- SEISMOLOGY