气候变化领域集成服务门户(CCPortal): Frictional Segmentation of the Chilean Megathrust From a Multivariate Analysis of Geophysical, Geological, and Geodetic Data

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DOI	10.1029/2020JB020647
	Frictional Segmentation of the Chilean Megathrust From a Multivariate Analysis of Geophysical, Geological, and Geodetic Data
	Molina D.; Tassara A.; Abarca R.; Melnick D.; Madella A.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	We present a formal seismic segmentation model of the Chile Margin derived from a multivariate analysis of gravity anomalies, basal friction and interplate locking from GPS velocities. These independent proxies of the frictional structure along the megathrust integrate over timescales of 101–107 years. We analyze their covariance using Principal Component Analysis (PCA) and extracting the Empirical Orthogonal Functions (EOFs) and Principal Components (PCs). We find that (a) the first and first + second PCA modes for the triple combination of the proxies explain (respectively) 41.4% and 69.4% of the total variance and (b) the first-order spatial pattern of each isolated proxy is largely reproduced when it is combined with the other two proxies. This suggests that the three proxies share a first order along-trench tendency that must be connected through a common physical process. Comparing our results with rupture areas of earthquakes and using the rate-and-state friction theory, we infer that trench-perpendicular PCs reflect the limits of the velocity-weakening (VW) seismogenic zone. Polarity changes in along-trench EOFs (mostly for gravity) mark changes between unstable and conditionally stable frictional regimes inside the VW zone and we used them to define the boundaries of 17 unitary segments. These segments correlate with first-order tectonic features of the Andes at >103-km scales as well as with zones of multi-segment ruptures at 102-km scale. We analyze the combined influence of subducting and upper-plate geologic features on the nature of persistent seismic barriers. Our results have implications for understanding seismotectonic processes along the Andean margin and elsewhere. © 2021. American Geophysical Union. All Rights Reserved.
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/187075
作者单位	Departamento Ciencias de la Tierra, Facultad de Ciencias Químicas, Universidad de Concepción, Concepción, Chile; Millennium Nucleus The Seismic Cycle Along Subduction Zones CYCLO, Valdivia, Chile; Departamento de Geofísica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción, Chile; Instituto de Ciencias de la Tierra, TAQUACh, Universidad Austral de Chile, Valdivia, Chile; Institut für Geowissenschaften, Universität Tübingen, Tübingen, Germany
推荐引用方式 GB/T 7714	Molina D.,Tassara A.,Abarca R.,et al. Frictional Segmentation of the Chilean Megathrust From a Multivariate Analysis of Geophysical, Geological, and Geodetic Data[J],2021,126(6).
APA	Molina D.,Tassara A.,Abarca R.,Melnick D.,&Madella A..(2021).Frictional Segmentation of the Chilean Megathrust From a Multivariate Analysis of Geophysical, Geological, and Geodetic Data.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Molina D.,et al."Frictional Segmentation of the Chilean Megathrust From a Multivariate Analysis of Geophysical, Geological, and Geodetic Data".Journal of Geophysical Research: Solid Earth 126.6(2021).