气候变化领域集成服务门户(CCPortal): Stress Promotion of the 1958 Mw∼7.8 Fairweather Fault Earthquake and Others in Southeast Alaska by Glacial Isostatic Adjustment and Inter-earthquake Stress Transfer

CCPortal

DOI	10.1029/2020JB020411
	Stress Promotion of the 1958 Mw∼7.8 Fairweather Fault Earthquake and Others in Southeast Alaska by Glacial Isostatic Adjustment and Inter-earthquake Stress Transfer
	Rollins C.; Freymueller J.T.; Sauber J.M.
发表日期	2021
ISSN	21699313
卷号	126 期号:1
英文摘要	We assess how recent glacial isostatic adjustment (GIA) and inter-earthquake stress transfer modulated the state of stress on major faults in Southeast Alaska, and how these effects may have influenced recent large and moderate earthquakes. The Glacier Bay Icefield has lost >3,000 km3 of ice since ca. 1770, with ice thinning up to 1.5 km, and the rest of southeast Alaska has been deglaciating since ca. 1900. The resulting GIA response in the solid earth produces present-day surface uplift rates of up to ∼4 cm/yr, among the fastest on Earth. This rapid deformation occurs directly alongside and atop the Fairweather Fault, which accommodates 4–5 cm/yr of right-lateral motion through slip in frequent large earthquakes, recently including a Mw∼7.8 earthquake in 1958. We find that the 1958 earthquake nucleated very close to the location of maximum GIA-induced Coulomb stress increase on the Fairweather Fault between 1770 and 1958 (estimated at ∼0.2–0.6 MPa), on the only section of fault where GIA-induced stress changes had involved both right-lateral shearing and unclamping. The September 10, 1899 Mw∼8.1 Yakutat Bay earthquake also promoted failure on at least the northwest part of the eventual 1958 rupture. In turn, the 1899 and 1958 earthquakes and GIA promoted failure along the St. Elias compressional margin, the site of a Mw∼7.4 event in 1979. While rapid tectonic loading is very likely the main driver of earthquakes in southeast Alaska, we estimate that 23 of 30 instrumentally constrained Mw ≥ 5.0 earthquakes in this region were also promoted by post-1770 GIA. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	coulomb stress transfer; glacial isostatic adjustment; mantle viscoelasticity; postglacial rebound; strike-slip faulting; thrust faulting
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/187400
作者单位	Department of Geosciences, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United States; Department of Earth and Environmental Sciences, Michigan State University, East LansingMI, United States; School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Lab for Geodesy and Geophysics, NASA Goddard Space Flight Center, Greenbelt, MD, United States
推荐引用方式 GB/T 7714	Rollins C.,Freymueller J.T.,Sauber J.M.. Stress Promotion of the 1958 Mw∼7.8 Fairweather Fault Earthquake and Others in Southeast Alaska by Glacial Isostatic Adjustment and Inter-earthquake Stress Transfer[J],2021,126(1).
APA	Rollins C.,Freymueller J.T.,&Sauber J.M..(2021).Stress Promotion of the 1958 Mw∼7.8 Fairweather Fault Earthquake and Others in Southeast Alaska by Glacial Isostatic Adjustment and Inter-earthquake Stress Transfer.Journal of Geophysical Research: Solid Earth,126(1).
MLA	Rollins C.,et al."Stress Promotion of the 1958 Mw∼7.8 Fairweather Fault Earthquake and Others in Southeast Alaska by Glacial Isostatic Adjustment and Inter-earthquake Stress Transfer".Journal of Geophysical Research: Solid Earth 126.1(2021).