气候变化领域集成服务门户(CCPortal): New Insights Into the Slip Budget at Nankai: An Iterative Approach to Estimate Coseismic Slip and Afterslip

CCPortal

DOI	10.1029/2020JB020833
	New Insights Into the Slip Budget at Nankai: An Iterative Approach to Estimate Coseismic Slip and Afterslip
	Sherrill E.M.; Johnson K.M.
发表日期	2021
ISSN	21699313
卷号	126 期号:2
英文摘要	The slip budget at a subduction zone megathrust is met by a spectrum of slip behaviors including coseismic slip from great earthquakes, afterslip, episodic tremor and slip (ETS), long-term slow slip events (SSEs), and quasisteady interseismic creep. Long-term geodetic monitoring at the Nankai subduction zone in southwest Japan has recorded deformation observations spanning nearly a complete earthquake cycle, making this region the best study area for obtaining a full understanding of how the slip budget is partitioned along the interface and how the rheological conditions evolve through space and time. In this work, we conduct an iterative inversion of vertical surface displacement data to jointly estimate coseismic slip during the 1944/46 Tonankai and Nankai earthquakes, spatiotemporal afterslip history following those earthquakes, and postseismic mantle flow. A suite of postseismic models with variable elastic slab and plate geometry and mantle viscosity all show at least 30 years of sustained afterslip within the ETS zone and the gap between the top of the ETS zone and the fully coupled zone. This result demonstrates that stable, long-duration afterslip is possible in the ETS zone. Summing the estimated cumulative slip from this study with estimates from previous studies of cumulative slip during the interseismic period, including episodic SSEs, we find that eastern Shikoku island has nearly met all of its slip budget for a 150-year interseismic cycle, whereas western Shikoku island has a slip deficit of nearly half the budget (4 out of 8.25 meters) above 20 km depth on the subduction interface. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	afterslip; coseismic; episodic tremor and slip (ETS) zone; iterative inversion; Nankai subduction zone; postseismic
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/187383
作者单位	Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, IN, United States
推荐引用方式 GB/T 7714	Sherrill E.M.,Johnson K.M.. New Insights Into the Slip Budget at Nankai: An Iterative Approach to Estimate Coseismic Slip and Afterslip[J],2021,126(2).
APA	Sherrill E.M.,&Johnson K.M..(2021).New Insights Into the Slip Budget at Nankai: An Iterative Approach to Estimate Coseismic Slip and Afterslip.Journal of Geophysical Research: Solid Earth,126(2).
MLA	Sherrill E.M.,et al."New Insights Into the Slip Budget at Nankai: An Iterative Approach to Estimate Coseismic Slip and Afterslip".Journal of Geophysical Research: Solid Earth 126.2(2021).