气候变化领域集成服务门户(CCPortal): Stress Drop Variations in the Region of the 2014 MW8.1 Iquique Earthquake, Northern Chile

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DOI	10.1029/2020JB020112
	Stress Drop Variations in the Region of the 2014 MW8.1 Iquique Earthquake, Northern Chile
	Folesky J.; Kummerow J.; Shapiro S.A.
发表日期	2021
ISSN	21699313
卷号	126 期号:4
英文摘要	We compute stress drops from P and S phase spectra for 534 earthquakes in the source region of the 2014 MW8.1 Iquique megathrust earthquake in the northern Chilean subduction zone. An empirical Green's function based method is applied to suitable event pairs selected by template matching of eight years of continuous waveform data. We evaluate the parameters involved in the stress drop estimation, consider the effect of the local velocity structure and apply an empirical linear relation between P and S phase related geometry factors (k values). Data redundancy produced by multiple empirical Green's function and the combination of P and S phase spectra leads to a substantial reduction of uncertainty and robust stress drop estimates. The resulting stress drop values show a well-defined log-normal distribution with a median value of 4.36 MPa; most values range between 0.1 and 100 MPa. There is no evidence for systematic large scale lateral variations of stress drop. A detailed analysis reveals several regions of increased median stress drop, an increase with distance to the interface, but no consistent increase with depth. This suggests that fault regime and fault strength have a stronger impact on the stress drop behavior than absolute stresses. Interestingly, we find a weak time-dependence of the median stress drop, with an increase immediately before the April 1, 2014 MW8.1 Iquique mainshock, a continuous reduction thereafter and a subsequent recovery to average values. Additionally, the data set indicates a relatively strong dependence of stress drop on magnitude which extends over the entire analyzed magnitude range. © 2021. The Authors.
英文关键词	brune type stress drop; northern Chile; spatio-temporal variability; spectral ratio; subduction interface seismicity; template matching
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/187196
作者单位	Department of Geophysics, Freie Universität Berlin, Berlin, Germany
推荐引用方式 GB/T 7714	Folesky J.,Kummerow J.,Shapiro S.A.. Stress Drop Variations in the Region of the 2014 MW8.1 Iquique Earthquake, Northern Chile[J],2021,126(4).
APA	Folesky J.,Kummerow J.,&Shapiro S.A..(2021).Stress Drop Variations in the Region of the 2014 MW8.1 Iquique Earthquake, Northern Chile.Journal of Geophysical Research: Solid Earth,126(4).
MLA	Folesky J.,et al."Stress Drop Variations in the Region of the 2014 MW8.1 Iquique Earthquake, Northern Chile".Journal of Geophysical Research: Solid Earth 126.4(2021).