HR: 0800h
AN: G11A-0766    [Abstracts]
TI: Uplift "potential" derived from GPS horizontal measurements and its geological implications in Taiwan
AU: * Yen, J
EM: jyyen@csrsr.ncu.edu.tw
AF: Center for Space and Remote Sensing Research, National Central University, No. 300, Jungda Road, Chung-Li, Flo 320 Taiwan
AU: Chang, T
EM: changty@earth.ncu.edu.tw
AF: Institute of Geophysics, National Central University, No. 300, Jungda Road, Chung-Li, Flo 320 United States
AU: Lundberg, N
EM: lundberg@gly.fsu.edu
AF: Department of Geological Sciences, Florida State University, 306 Carraway Building, Tallahassee, Fl 32301 United States
AB: A mathematic model based on conservation equation was constructed to evaluate a theoretical uplift rate based on the published GPS measurements around Taiwan, which is undergoing a collision between the Luzon arc and the Eurasian continental margin. With this simple model, "potential for uplift" is calculated. The potential uplift rate is generally higher in the east and decreases westward. Segmentation of the tectonic regimes onland Taiwan can be clearly observed from the result. For example, the northeastern Taiwan (Ilan Plain) has negative values of potential uplift, which means the whole Ilan Plain is undergoing subsidence. In fact, the Ilan Plain is the westernmost extension of the opening Okinawa trough. The calculated uplift rates were then compared with the topography in order to evaluate whether areas with higher theoretical uplift rates are areas with higher elevation. The coherence between calculated uplift rate and the topographic data were done by calculating their cross-correlation. The results show that areas with high conherence are areas with higher seismicity. The underlying rationales of this observation are not fully understood, however, we speculate that the differences in time scale of deformation or whether surface processes are involved might be responsible for this observation.
DE: 8102 Continental contractional orogenic belts
DE: 8107 Continental neotectonics
DE: 1200 GEODESY AND GRAVITY
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting