气候变化领域集成服务门户(CCPortal): Afterslip and Spontaneous Aseismic Slip on the Anza Segment of the San Jacinto Fault Zone, Southern California

CCPortal

DOI	10.1029/2020JB020460
	Afterslip and Spontaneous Aseismic Slip on the Anza Segment of the San Jacinto Fault Zone, Southern California
	Shaddox H.R.; Schwartz S.Y.; Bartlow N.M.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	Understanding the interplay of seismic and aseismic slip is key in seismic hazard evaluation. It is particularly important to know if the same or nearby fault segments can host different slip modes and understand the transition between modes of slip. We investigate this in the trifurcation area of the Anza segment of the San Jacinto fault where deep creep driving seismicity below the geodetic locking depth has been proposed. We focus on periods following local moderate-sized earthquakes by combining the occurrence of highly correlated families of earthquakes (i.e., closely spaced or partially overlapping events) that we describe here as near-repeating earthquakes, seismicity, and borehole strainmeter data. We find that all Mw > 4.5 earthquakes between 2010 and 2020 triggered afterslip with coplanar families of near-repeating earthquakes and off-fault microseismicity. These observations include newly detected afterslip following the June 10, 2016 Mw 5.2 and April 4, 2020 Mw 4.9 local earthquakes. Afterslip geometries defined by the near-repeating earthquake families are consistent with strain change observations. We conclude that families of near-repeating earthquakes, similar to low-frequency earthquakes within tremor, can be useful indicators of aseismic slip transients and can reveal faulting complexities during aseismic slip. Further, we identify the first evidence of spontaneous aseismic slip in the Anza region from near-repeating earthquake families on two minor faults in 2015. Taken together, our observations support a model where deep microseismicity is located in a transitional region at the bottom of the seismogenic zone with spatially heterogeneous frictional properties that produce frequent aseismic slip transients near Anza. © 2021. The Authors.
英文关键词	afterslip; aseismic slip; near-repeating earthquakes
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/187042
作者单位	Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA, United States; Department of Geology, University of Kansas, Lawrence, KS, United States
推荐引用方式 GB/T 7714	Shaddox H.R.,Schwartz S.Y.,Bartlow N.M.. Afterslip and Spontaneous Aseismic Slip on the Anza Segment of the San Jacinto Fault Zone, Southern California[J],2021,126(6).
APA	Shaddox H.R.,Schwartz S.Y.,&Bartlow N.M..(2021).Afterslip and Spontaneous Aseismic Slip on the Anza Segment of the San Jacinto Fault Zone, Southern California.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Shaddox H.R.,et al."Afterslip and Spontaneous Aseismic Slip on the Anza Segment of the San Jacinto Fault Zone, Southern California".Journal of Geophysical Research: Solid Earth 126.6(2021).