气候变化领域集成服务门户(CCPortal): What Triggers Caldera Ring-Fault Subsidence at Ambrym Volcano? Insights From the 2015 Dike Intrusion and Eruption

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DOI	10.1029/2020JB020277
	What Triggers Caldera Ring-Fault Subsidence at Ambrym Volcano? Insights From the 2015 Dike Intrusion and Eruption
	Shreve T.; Grandin R.; Smittarello D.; Cayol V.; Pinel V.; Boichu M.; Morishita Y.
发表日期	2021
ISSN	21699313
卷号	126 期号:6
英文摘要	Surface deformation accompanying dike intrusions is dominated by uplift and horizontal motion directly related to the intrusions. In some cases, it includes subsidence due to associated magma reservoir deflation. When reservoir deflation is large enough, it can form, or reactivate preexisting, caldera ring-faults. Ring-fault reactivation, however, is rarely observed during moderate-sized eruptions. On February 21, 2015 at Ambrym volcano in Vanuatu, a basaltic dike intrusion produced more than 1 m of coeruptive uplift, as measured by InSAR, synthetic aperture radar correlation, and Multiple Aperture Interferometry. Here, we show that an average of ∼40 cm of slip occurred on a normal caldera ring-fault during this moderate-sized (VEI < 3) event, which intruded a volume of ∼24 × 106 m3 and erupted ∼9.3 × 106 m3 of lava (DRE). Using the 3D Mixed Boundary Element Method, we explore the stress change imposed by the opening dike and the depressurizing reservoir on a passive, frictionless fault. Normal fault slip is promoted when stress is transferred from a depressurizing reservoir beneath one of Ambrym's main craters. After estimating magma compressibility, we provide an upper bound on the critical fraction (f = 7%) of magma extracted from the reservoir to trigger fault slip. We infer that broad basaltic calderas may form in part by hundreds of subsidence episodes no greater than a few meters, as a result of magma extraction from the reservoir during moderate-sized dike intrusions. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	basaltic volcanism; calderas; rift zones; ring-faults; stress transfer
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/187062
作者单位	Université de Paris, Institut de physique du globe de Paris, CNRS, Paris, France; Now at Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, United States; Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, Université Gustave Eiffel, ISTerre, Grenoble, France; Now at The European Center for Geodynamics and Seismology, Walferdange, Luxembourg; Université Clermont Auvergne, CNRS, IRD, OPGC, Laboratoire Magmas et Volcans, Clermont-Ferrand, France; Univ. Lille, UMR 8518 – LOA – Laboratoire d'Optique Atmosphérique, Lille, France; CNRS, UMR 8518, Lille, France; Geospatial Information Authority of Japan, Ibaraki, Japan
推荐引用方式 GB/T 7714	Shreve T.,Grandin R.,Smittarello D.,et al. What Triggers Caldera Ring-Fault Subsidence at Ambrym Volcano? Insights From the 2015 Dike Intrusion and Eruption[J],2021,126(6).
APA	Shreve T..,Grandin R..,Smittarello D..,Cayol V..,Pinel V..,...&Morishita Y..(2021).What Triggers Caldera Ring-Fault Subsidence at Ambrym Volcano? Insights From the 2015 Dike Intrusion and Eruption.Journal of Geophysical Research: Solid Earth,126(6).
MLA	Shreve T.,et al."What Triggers Caldera Ring-Fault Subsidence at Ambrym Volcano? Insights From the 2015 Dike Intrusion and Eruption".Journal of Geophysical Research: Solid Earth 126.6(2021).