Surface deformation and tectonic setting of Taiwan inferred from a GPS velocity field

被引:68
作者
Bos, AG
Spakman, W
Nyst, MCJ
机构
[1] Univ Utrecht, Fac Earth Sci, NL-3584 CD Utrecht, Netherlands
[2] Delft Univ Technol, Delft Inst Earth Oriented Space Res, Delft, Netherlands
关键词
tectonic setting; GPS data; Taiwan; surface deformation;
D O I
10.1029/2002JB002336
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
[1] We have determined the present-day surface deformation of Taiwan by computing the velocity gradient field and fault slip from 143 GPS velocity vectors. In southern Taiwan the derived strain and rotation rates and fault slips are indicative of lateral extrusion toward the south. In northern Taiwan we infer the onset of gravitational collapse which is induced by the on-land extension of the Okinawa Trough. In the eastern Central Range the observed inverted NW-SE extension is consistent with geological observations and high heat flow measurements. This could be the result of exhumation of crustal material. The model further shows a significant decrease in slip rate northward along the Longitudinal Valley fault at 23.7degreesN. The northern Coastal Range shows high strain rates and two oppositely rotating blocks. By combining the surface deformation model with seismicity data and seismic tomography we are able to propose a coherent model for the present-day tectonic activity. Both seismicity and tomography show further evidence for active, southward propagating exhumation of a crustal slice in the eastern Central Range. Offshore east Taiwan we deduce strong evidence of a southward propagating crustal tear fault, accommodating most of the Philippine Sea Plate-Eurasian Plate convergence. The tear is the crustal response to incipient northwestward subduction of the Philippine Sea Plate. Thus the Ryukyu Trench is bending southward becoming almost perpendicular to the convergence direction, while subduction of the Philippine Sea Plate continues. In this setting a sudden rapid southward propagation of the afore mentioned tear is conceivable.
引用
收藏
页数:18
相关论文
共 76 条
[1]   TECTONIC ANALYSIS AND THE EVOLUTION OF A CURVED COLLISION BELT - THE HSUEHSHAN RANGE, NORTHERN TAIWAN [J].
ANGELIER, J ;
BERGERAT, F ;
CHU, HT ;
LEE, TQ .
TECTONOPHYSICS, 1990, 183 (1-4) :77-96
[2]   Shear concentration in a collision zone: Kinematics of the Chihshang Fault as revealed by outcrop-scale quantification of active faulting, Longitudinal Valley, eastern Taiwan [J].
Angelier, J ;
Chu, HT ;
Lee, JC .
TECTONOPHYSICS, 1997, 274 (1-3) :117-143
[3]   Active faulting and earthquake hazard: The case study of the Chihshang Fault, Taiwan [J].
Angelier, J ;
Chu, HT ;
Lee, JC ;
Hu, JC .
JOURNAL OF GEODYNAMICS, 2000, 29 (3-5) :151-185
[4]  
[Anonymous], J GEOL SOC CHINA
[5]  
[Anonymous], 1981, MEMOIROFTHEGEOLOGICA
[6]  
[Anonymous], PETROL GEOL TAIWAN
[7]  
BARR TD, 1990, GEOLOGY, V18, P111, DOI 10.1130/0091-7613(1990)018<0111:COFASI>2.3.CO
[8]  
2
[9]   ACTIVE COLLISION IN EASTERN TAIWAN - THE COASTAL RANGE [J].
BARRIER, E ;
ANGELIER, J .
TECTONOPHYSICS, 1986, 125 (1-3) :39-72
[10]   Contemporary horizontal velocity and strain rate fields of the Pacific-Australian plate boundary zone through New Zealand [J].
Beavan, J ;
Haines, J .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 2001, 106 (B1) :741-770