气候变化领域集成服务门户(CCPortal): Ground Deformation After a Caldera Collapse: Contributions of Magma Inflow and Viscoelastic Response to the 2015–2018 Deformation Field Around Bárðarbunga, Iceland

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DOI	10.1029/2020JB020157
	Ground Deformation After a Caldera Collapse: Contributions of Magma Inflow and Viscoelastic Response to the 2015–2018 Deformation Field Around Bárðarbunga, Iceland
	Li S.; Sigmundsson F.; Drouin V.; Parks M.M.; Ófeigsson B.G.; Jónsdóttir K.; Grapenthin R.; Geirsson H.; Hooper A.; Hreinsdóttir S.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	Improvement of our understanding of the role of ground deformation due to viscoelastic relaxation following eruptions is important, as the generated signals can resemble renewed magma inflow. We study post-eruptive unrest at the subglacial Bárðarbunga volcano, Iceland, after a caldera collapse and major magma drainage in 2014–2015. Elevated seismicity began about 6 months after the eruption ended, including nine Mlw > 4.5 earthquakes. Global Navigation Satellite System and Sentinel-1 Interferometric Synthetic Aperture Radar geodesy are applied to evaluate post-eruptive ground deformation from 2015 to 2018. Horizontal velocities locally exceed 10 cm/year and rapidly decay with distance away from the caldera. We explore two end-member models and their combination to explain the post-eruptive deformation field: 1) viscoelastic relaxation caused by the co-eruptive caldera collapse and magma withdrawal, and 2) renewed magma inflow. We find parameter combinations for each model that explain the observed ground deformation. The purely viscoelastic relaxation model, consisting of a half-space composed of a 7-km thick elastic layer on top of a viscoelastic layer with a viscosity of 3.0 × 1018 Pa s reproduces broadly the observations. A simple magma inflow model consisting of a single point source with an inflow rate of 1 × 107 m3/year at 0.7 km depth broadly fits the observations, but may be unrealistic. A more elaborate model of magma inflow into a 10-km deep sill combined with slip on the caldera ring fault explains the observations well. Our results suggest that the co-eruptive deformation field is likely influenced by viscoelastic relaxation, renewed magma inflow, or a combination of both processes. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Bárðarbunga; GNSS; InSAR; viscoelasticity; volcanic unrest
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/187255
作者单位	Nordic Volcanological Center, Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland; Iceland Geosurvey ÍSOR, Reykjavik, Iceland; Icelandic Meteorological Office, Reykjavík, Iceland; Geophysical Institute and Dept. of Geosciences, University of Alaska Fairbanks, Fairbanks, AK, United States; School of Earth and Environment, COMET, University of Leeds, England, United Kingdom; GNS Science, Lower Hutt, New Zealand
推荐引用方式 GB/T 7714	Li S.,Sigmundsson F.,Drouin V.,等. Ground Deformation After a Caldera Collapse: Contributions of Magma Inflow and Viscoelastic Response to the 2015–2018 Deformation Field Around Bárðarbunga, Iceland[J],2021,126(3).
APA	Li S..,Sigmundsson F..,Drouin V..,Parks M.M..,Ófeigsson B.G..,...&Hreinsdóttir S..(2021).Ground Deformation After a Caldera Collapse: Contributions of Magma Inflow and Viscoelastic Response to the 2015–2018 Deformation Field Around Bárðarbunga, Iceland.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Li S.,et al."Ground Deformation After a Caldera Collapse: Contributions of Magma Inflow and Viscoelastic Response to the 2015–2018 Deformation Field Around Bárðarbunga, Iceland".Journal of Geophysical Research: Solid Earth 126.3(2021).