faultparametersofthe2012sumatraearthquakeestimatedfromgracegravityandgravitygradientchanges

doi:10.6038/cjg2019M0600

NTSC-IR

	faultparametersofthe2012sumatraearthquakeestimatedfromgracegravityandgravitygradientchanges
	Zheng ZengJi 1; Jin ShuangGen 1; Fan LiHong 5
	2019
发表期刊	chinesejournalofgeophysicschineseedition
ISSN	0001-5733
卷号	62 期号:11 页码:4129
摘要	The M-w = 8. 6 earthquakes occurred on 11 April 2012 and ruptured off the west coast of northern Sumatra. The fault slip models of the earthquake were estimated from different data, but have large differences in the strike-slip nature of faults. GRACE-derived co-seismic gravity changes cover the epicenter area, which can provide good constraint on the fault parameters inversion. In this paper, co-seismic gravity and gradient changes of the 2012 Sumatra earthquake are extracted from GRACE time-variable gravity field and the superiority of the northward component is presented. The theoretical calculation results of the fault model are compared with the GRACE and the sensitivity of the T-xx (north-to-north gravity gradient) to the fault parameters is analyzed. Finally, the fault parameters of the earthquake are retrieved based on the particle swarm optimization (PSO) algorithm and the Okubo dislocation model. The results show that the GRACE-observed co-seismic gravity and gravity gradient changes are in good agreement with the model-estimated results in spatial pattern, but have difference in amplitudes. The strip errors can be substantially suppressed by the north components of gravity and gravity gradients changes, where the noise level of g, (north gravity change) and T-xy are the lowest, followed by T-xz (northto-up gravity gradient) and the worst is the T-xy (north-to-east gravity gradient). The T. is not sensitive to the depth of the fault, but sensitive to other fault parameters. The GRACE-inverted strike angle, dip angle, rake angle and average slip magnitude of the earthquake are 113. 63 degrees , 89. 99 degrees , 175. 26 degrees and 28. 18 m, respectively, indicating a moment-magnitude M-w = 8. 71. In addition, the GRACE-inverted rake angle shows that the earthquake is dominated by the right-lateral strike-slip.
关键词	M-W 8.6 ANDAMAN EARTHQUAKE SATELLITE GRAVITY CONSTRAINTS DISLOCATION SURFACE GRACE PSO algorithm Sumatra earthquake Fault parameters
DOI	10.6038/cjg2019M0600
语种	英语
引用统计
文献类型	期刊论文
条目标识符	http://210.72.145.45/handle/361003/9461
专题	中国科学院国家授时中心
作者单位	1.中国科学院国家天文台 2.中国科学院大学 3.Shaanxi Earthquake Agcy 4.南京大学 5.中国科学院国家授时中心
推荐引用方式 GB/T 7714	Zheng ZengJi,Jin ShuangGen,Fan LiHong. faultparametersofthe2012sumatraearthquakeestimatedfromgracegravityandgravitygradientchanges[J]. chinesejournalofgeophysicschineseedition,2019,62(11):4129.
APA	Zheng ZengJi,Jin ShuangGen,&Fan LiHong.(2019).faultparametersofthe2012sumatraearthquakeestimatedfromgracegravityandgravitygradientchanges.chinesejournalofgeophysicschineseedition,62(11),4129.
MLA	Zheng ZengJi,et al."faultparametersofthe2012sumatraearthquakeestimatedfromgracegravityandgravitygradientchanges".chinesejournalofgeophysicschineseedition 62.11(2019):4129.