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| Titel |
Crustal deformation and Coseismic displacement from Continuous GPS in the last Decade in Taiwan |
| VerfasserIn |
K.-C. Lin, J.-C. Hu, S.- Y. Wei, P.-C. Chang, K.-E. Ching, R.-J. Rau |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024862
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| Zusammenfassung |
| Using data at 150 Continuous GPS (CGPS) stations from September 1999 to December 2008,
we characterised the surface deformation in Taiwan after the Mw= 7.6 Chi-Chi earthquake of
September 21, 1999. During this period, three large earthquakes occured, Mw= 6.8
Hualien offshore earthquake on March 31, 2002, Mw= 6.8 Chengkung earthquake on
December 10, 2003 and Mw= 7.2 Pingtung offshore earthquake on December 26, 2006.
The smaller Mw= 5.9 Ilan and Mw= 5.6 Hualien earthquakes occurred in 2005.
From the CGPS data, the maximum coseismic deformation during the Chengkung
earthquake reached 17.9 cm (horizontal) and 20.3 cm (vertical). Hualien offshore
earthquake maximum coseismic deformation is 11.1 cm (horizontal) and -1.8 cm
(vertical). Pingtung offshore earthquake maximum coseismic deformation is 7.3 cm
(horizontal) and -6.6 cm (vertical). We compare the velocity field of the CGPS stations
relative to the stable continental shelf with the results of GPS measurements from
1990 to 1995 before the Chi-Chi earthquake. The stations of the eastern Taiwan
showed average displacement of 34.1-92.1 mm/yr towards azimuth 302Ë -322Ë ,
mainly revealing across-suture shortening. Significant postseismic deformation
after the Chi-Chi earthquake has been detected in the central Taiwan, with a major
increase in displacement velocity towards South China, about 29.1-46.2 mm/yr
towards azimuth 283Ë -289Ë . Extensional strain affects the Ilan and Pingtung
plains near belt tips, revealing lateral escape and extrusion towards the adjacent
subduction zones. Extensional strain also affects the southern Central Range, as a
consequence of the rapid uplift related to the southward-propagating collision process. |
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