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| Titel |
The velocity effects of large historical earthquakes in Chinese mainland |
| VerfasserIn |
Weijie Tan, Danan Dong, Bin Wu |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125844
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| Publikation (Nr.) |
 EGU/EGU2016-5493.pdf |
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| Zusammenfassung |
| Accompanying with the collision between Indian and Eurasian plates, China has experienced
decadal large earthquakes over the past 100 years. These large earthquakes are mainly located
along several seismic belts in Tien Shan, Tibet Plateau, and Northern China. The postseismic
deformation and stress accumulation induced by the historical earthquakes is important for
assess the contemporary seismic hazards. The postseismic deformation induced
by historical large earthquakes also influences the observed present day velocity
field.
The relaxation of the viscoelastic asthenosphere is modeled on a layered spherically
symmetric earth with Maxwell rheology. The layer’s thickness, the density p and the P-wave
velocity Vp are from PREM. The shear modulus are derived from the p and Vp. The
viscosity between lower crust and upper mantle adopted in this study is 1×1019
Pa.s.
Viscoelastic relaxation contributions due to 34 historical large earthquakes in China from
1900 to 2001 are calculated using VISCO1D-v3 program developed by Pollitz (1997). We
calculated the model predicted velocity field in 2015 in China caused by historical big
earthquakes. The pattern of predicted velocity field is consistent with the present movement
of crust, with peak velocities reaching 6mm yr−1. The region of Southwestern China moves
northeastwards, and also a significant rotation occurred at the edge of the Tibetan
Plateau. The velocity field caused by historical large earthquakes provides a base
to isolate the velocity field caused by the contemporary tectonic movement from
the geodetic observations. It also provides critical information to investigate the
regional stress accumulation and to assess the mid-term to long-term earthquake risk. |
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