气候变化领域集成服务门户(CCPortal): Convergence rate across the Nepal Himalaya and interseismic coupling on the Main Himalayan Thrust: Implications for seismic hazard

CCPortal

DOI	10.1029/2011JB009071
	Convergence rate across the Nepal Himalaya and interseismic coupling on the Main Himalayan Thrust: Implications for seismic hazard
	Ader, Thomas; Avouac, Jean-Philippe; Liu-Zeng, Jing; Lyon-Caen, Helene; Bollinger, Laurent; Galetzka, John; Genrich, Jeff; Thomas, Marion; Chanard, Kristel; Sapkota, Soma Nath; Rajaure, Sudhir; Shrestha, Prithvi; Ding, Lin; Flouzat, Mireille
通讯作者	Ader, T (通讯作者)
发表日期	2012
ISSN	2169-9313
EISSN	2169-9356
卷号	117
英文摘要	We document geodetic strain across the Nepal Himalaya using GPS times series from 30 stations in Nepal and southern Tibet, in addition to previously published campaign GPS points and leveling data and determine the pattern of interseismic coupling on the Main Himalayan Thrust fault (MHT). The noise on the daily GPS positions is modeled as a combination of white and colored noise, in order to infer secular velocities at the stations with consistent uncertainties. We then locate the pole of rotation of the Indian plate in the ITRF 2005 reference frame at longitude = -1.34 degrees +/- 3.31 degrees, latitude = 51.4 degrees +/- 0.3 degrees with an angular velocity of Omega = 0.5029 +/- 0.0072 degrees/Myr. The pattern of coupling on the MHT is computed on a fault dipping 10 degrees to the north and whose strike roughly follows the arcuate shape of the Himalaya. The model indicates that the MHT is locked from the surface to a distance of approximately 100 km down dip, corresponding to a depth of 15 to 20 km. In map view, the transition zone between the locked portion of the MHT and the portion which is creeping at the long term slip rate seems to be at the most a few tens of kilometers wide and coincides with the belt of midcrustal microseismicity underneath the Himalaya. According to a previous study based on thermokinematic modeling of thermochronological and thermobarometric data, this transition seems to happen in a zone where the temperature reaches 350 degrees C. The convergence between India and South Tibet proceeds at a rate of 17.8 +/- 0.5 mm/yr in central and eastern Nepal and 20.5 +/- 1 mm/yr in western Nepal. The moment deficit due to locking of the MHT in the interseismic period accrues at a rate of 6.6 +/- 0.4 x 10(19) Nm/yr on the MHT underneath Nepal. For comparison, the moment released by the seismicity over the past 500 years, including 14 M-W >= 7 earthquakes with moment magnitudes up to 8.5, amounts to only 0.9 x 10(19) Nm/yr, indicating a large deficit of seismic slip over that period or very infrequent large slow slip events. No large slow slip event has been observed however over the 20 years covered by geodetic measurements in the Nepal Himalaya. We discuss the magnitude and return period of M > 8 earthquakes required to balance the long term slip budget on the MHT.
关键词	OBLIQUE CONVERGENCE STRAIN ACCUMULATION SLIP EARTHQUAKE GPS DEFORMATION MODEL FAULT CYCLE TECTONICS
语种	英语
WOS研究方向	Geochemistry & Geophysics
WOS类目	Geochemistry & Geophysics
WOS记录号	WOS:000302871300001
来源期刊	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/258086
推荐引用方式 GB/T 7714	Ader, Thomas,Avouac, Jean-Philippe,Liu-Zeng, Jing,et al. Convergence rate across the Nepal Himalaya and interseismic coupling on the Main Himalayan Thrust: Implications for seismic hazard[J]. 中国科学院青藏高原研究所,2012,117.
APA	Ader, Thomas.,Avouac, Jean-Philippe.,Liu-Zeng, Jing.,Lyon-Caen, Helene.,Bollinger, Laurent.,...&Flouzat, Mireille.(2012).Convergence rate across the Nepal Himalaya and interseismic coupling on the Main Himalayan Thrust: Implications for seismic hazard.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,117.
MLA	Ader, Thomas,et al."Convergence rate across the Nepal Himalaya and interseismic coupling on the Main Himalayan Thrust: Implications for seismic hazard".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 117(2012).