Constraints on average Taiwan Reference Moho Discontinuity Model-receiver function analysis using BATS data

NCU Institutional Repository > 地球科學學院 > 地球科學學系 > 期刊論文 > Item 987654321/50532

jsp.display-item.identifier=請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/50532

题名:	Constraints on average Taiwan Reference Moho Discontinuity Model-receiver function analysis using BATS data
作者:	Wang,HL;Chen,HW;Zhu,LP
贡献者:	地球科學系
关键词:	BENEATH SOUTHWEST JAPAN;CRUSTAL STRUCTURE;WAVE-FORMS;SOUTHERN CALIFORNIA;MANTLE STRUCTURE;REFLECTIONS SMS;GROUND MOTION;TAIPEI BASIN;COLLISION;PLATEAU
日期:	2010
上传时间:	2012-03-27 17:36:18 (UTC+8)
出版者:	國立中央大學
摘要:	P>By analysing teleseismic waveform data, we propose a large-scale Taiwan Reference Moho Discontinuity Model (TRMDM) through coherent stacking and H-kappa analysis of receiver functions (RFs). Tectonic structural features are determined from accurate crustal thickness (H) and reliable Vp/Vs ratio (kappa) (consequently Poisson's ratio, Sigma) estimations for Taiwan. The best estimated regional average Moho depth is 33.5 +/- 2.9 km. Noted is a westward crustal thinning from 39 +/- 3.0 km in eastern Taiwan to 30 +/- 1.5 km in southeastern China. The averaged Moho depth is 23.0 +/- 2.5 km in northern Taiwan and increases to 33.5 +/- 2.0 km in the south. The markedly thin crust and high Vp/Vs ratio in northern Taiwan are mainly associated with backarc opening and magmatic activities. Based on H-kappa estimations and associated seismicity patterns beneath Suang-Long (SSLB) and adjacent four stations, we propose two Moho reference models that exhibit distinctive crustal thickening in central Taiwan. The spatial variations of crustal thickness models show strong lateral change in the Moho topography. The thick crust in the south, thin crust in the north and transition in central Taiwan mark the different tectonic units between the subduction wedge and the collision prism onshore. In view of the following list of constraints: thicker crust in the south than in the north; eastward crust thickening; significant Moho depth changes; clear 9-11 s subcrustal boundaries from five stations; the compelling thickening of crust and upper mantle beneath the central mountain belt; seismicity patterns with the absence of mantle earthquake in the Wadati-Benioff zone; regional geological features; the occurrence of the inland Chi-Chi earthquake; the compelling low kappa at YULB (1.58 +/- 0.13) that may extend to central Taiwan at SSLB (1.59 +/- 0.23); relatively thick crust at YULB (39.5 +/- 1.6 km) and SSLB (40.5 +/- 1.3 km or 52.5 +/- 1.5 km), and finally, the apparent horizontal offset between highest Yu Shan Mountain and the deepest Moho at SSLB, we are able to suggest that the initial subduction of the Eurasian Plate occurred in southern Taiwan and most likely extended to the transition zone in central Taiwan. Although the current RF study is limited by large interstation distance, our analysis provides more notable constraints than previous studies to explicitly determine the characteristic features of Moho discontinuity. This detailed approach means that rather than treating the tectonic framework as a whole heterogeneous lithospheric feature, clear Moho boundary geometry variations indicate that active orogenic processes and differential tectonic stress loading create separate and complex crustal and subcrustal-to-upper-mantle structural features caused by the arc-continent collision.
關聯:	GEOPHYSICAL JOURNAL INTERNATIONAL
显示于类别:	[地球科學學系] 期刊論文

文件中的档案:

档案	描述	大小	格式	浏览次数
index.html		0Kb	HTML	689	检视/开启

在NCUIR中所有的数据项都受到原著作权保护.

社群 sharing

数据加载中.....