气候变化领域集成服务门户(CCPortal): Moment Tensors of Ring-Faulting at Active Volcanoes: Insights Into Vertical-CLVD Earthquakes at the Sierra Negra Caldera, Galápagos Islands

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DOI	10.1029/2021JB021693
	Moment Tensors of Ring-Faulting at Active Volcanoes: Insights Into Vertical-CLVD Earthquakes at the Sierra Negra Caldera, Galápagos Islands
	Sandanbata O.; Kanamori H.; Rivera L.; Zhan Z.; Watada S.; Satake K.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	Moderate earthquakes (Mw > 5) with moment tensors (MTs) dominated by a vertical compensated-linear-vector-dipole (vertical-CLVD) component are often generated by dip slip along a curved ring-fault system at active volcanoes. However, relating their MTs to ring-fault parameters has been proved difficult. The objective of this study is to find a robust way of estimating some ring-fault parameters based on their MT solutions obtained from long-period seismic records. We first model the MTs of idealized ring-faulting and show that MT components representing the vertical-CLVD and vertical strike-slip mechanisms are resolvable by the deviatoric MT inversion using long-period seismic waves, whereas a component representing the vertical dip-slip mechanism is indeterminate owing to a shallow source depth. We then propose a new method for estimating the arc angle and orientation of ring-faulting using the two resolvable MT components. For validation, we study a vertical-CLVD earthquake that occurred during the 2005 volcanic activity at the Sierra Negra caldera, Galápagos Islands. The resolvable MT components are stably determined with long-period seismic waves, and our estimation of the ring-fault parameters is consistent with the ring-fault geometry identified by previous geodetic studies and field surveys. We also estimate ring-fault parameters of two earthquakes that took place during the 2018 activity at the caldera, revealing significant differences between the two earthquakes in terms of slip direction and location. These results show the usefulness of our method for estimating ring-fault parameters, enabling us to examine the kinematics and structures below active volcanoes with ring faults that are distributed globally. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	caldera; moment tensor inversion; ring fault; Sierra Negra caldera; surface wave; volcanic earthquake
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/187046
作者单位	Earthquake Research Institute, The University of Tokyo, Tokyo, Japan; National Research Institute for Earth Science and Disaster Resilience, Ibaraki, Japan; Seismological Laboratory, California Institute of Technology, Pasadena, CA, United States; Université de Strasbourg, CNRS, ITES UMR 7063, Strasbourg, France
推荐引用方式 GB/T 7714	Sandanbata O.,Kanamori H.,Rivera L.,et al. Moment Tensors of Ring-Faulting at Active Volcanoes: Insights Into Vertical-CLVD Earthquakes at the Sierra Negra Caldera, Galápagos Islands[J],2021,126(6).
APA	Sandanbata O.,Kanamori H.,Rivera L.,Zhan Z.,Watada S.,&Satake K..(2021).Moment Tensors of Ring-Faulting at Active Volcanoes: Insights Into Vertical-CLVD Earthquakes at the Sierra Negra Caldera, Galápagos Islands.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Sandanbata O.,et al."Moment Tensors of Ring-Faulting at Active Volcanoes: Insights Into Vertical-CLVD Earthquakes at the Sierra Negra Caldera, Galápagos Islands".Journal of Geophysical Research: Solid Earth 126.6(2021).