气候变化领域集成服务门户(CCPortal): Crustal Stress State in Taiwan: Moderately Strong Crust Supporting Gravitational and Flexural Loading

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DOI	10.1029/2020JB019530
	Crustal Stress State in Taiwan: Moderately Strong Crust Supporting Gravitational and Flexural Loading
	Yang Y.-R.; Johnson K.M.
发表日期	2020
ISSN	21699313
卷号	125 期号:11
英文摘要	In Taiwan and other contractional tectonic wedges, there is evidence that the basal detachment is very weak and the overlying crust is relatively strong. In this study, we compute the absolute deviatoric 3-D stress field in Taiwan using focal mechanism data and coseismic stress changes for the 1999 M7.6 Chi-Chi earthquake. We estimate a minimum coefficient of friction of 0.3 in the upper 15 km crust, assuming hydrostatic pore pressure, consistent with a moderately strong crust. The estimated stress state is consistent with primary tectonic structures of Taiwan. The maximum compressive stress in the fold and thrust belt and the Coastal Range is approximately aligned with relative motion of the Eurasian and the Philippine Sea Plates, but the minimum and intermediate principal stresses vary laterally and with depth. A reverse-faulting stress regime wraps around the Peikang high in western Taiwan suggesting inherited basement structure influences crustal stress state. Vertical maximum compressive stress is inferred under the high topography of the Central Range mountains. We present a simple stress model for Taiwan assuming spatial variations in gravitational potential energy are supported elastically. The model stress state is broadly consistent with the stress inversion result. The model shows that vertical maximum compressive stress in the Central Range is a result of high topography and thick crustal root. Consistent with a moderately strong crust, the model deviatoric stresses in areas of high seismicity in Taiwan are of the order 50–100 MPa. Lower deviatoric stresses under the Central Range are consistent with low rates of observed seismicity. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	faulting; orogeny; stress
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187523
作者单位	Department of Civil Engineering, National Taiwan University, Taipei, Taiwan; Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, Bloomington, IN, United States
推荐引用方式 GB/T 7714	Yang Y.-R.,Johnson K.M.. Crustal Stress State in Taiwan: Moderately Strong Crust Supporting Gravitational and Flexural Loading[J],2020,125(11).
APA	Yang Y.-R.,&Johnson K.M..(2020).Crustal Stress State in Taiwan: Moderately Strong Crust Supporting Gravitational and Flexural Loading.Journal of Geophysical Research: Solid Earth,125(11).
MLA	Yang Y.-R.,et al."Crustal Stress State in Taiwan: Moderately Strong Crust Supporting Gravitational and Flexural Loading".Journal of Geophysical Research: Solid Earth 125.11(2020).