气候变化领域集成服务门户(CCPortal): Glacial pumping of a magma-charged lithosphere: A model for glaciovolcanic causality in magmatic arcs

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DOI	10.1016/j.epsl.2020.116500
	Glacial pumping of a magma-charged lithosphere: A model for glaciovolcanic causality in magmatic arcs
	Wilson A.M.; Russell J.K.
发表日期	2020
ISSN	0012821X
卷号	548
英文摘要	Glacial loading and unloading can influence the rates and timing of magmatism in tectonic settings where the lithosphere is relatively thin and hot. In continental arcs, where the lithosphere is substantially thicker, nominal loading by surface glaciers is unlikely to affect the production of subduction-related magmas. However, geologic evidence suggests that a causal linkage between volcanism and glaciations in arcs does exist. The last deglaciation of the Garibaldi volcanic belt in southwestern British Columbia, Canada saw a ∼5-fold volumetric increase in volcanism over the mean Pleistocene (background) rate that coincided with ∼400 m of rapid postglacial crustal uplift. Here, we use a cylindrical, thin plate bending approximation to calculate the horizontally oriented stresses developed in the crust during glacial loading/unloading (up to ±12 MPa). The distribution of compressive and extensional stresses is shown to modulate magma transport and storage by facilitating or suppressing magma ascent by dike propagation. We use Monte Carlo simulations to track the depth of upward migrating magma bodies in the crust over a single glacial cycle (i.e., during crustal depression and rebound). During loading, volcanism is suppressed as magma becomes trapped by compressive deviatoric stress in the upper part of the crust. During unloading, relaxation of this stress acts to release accumulated magma from the upper crust and causes an increase in eruption rate immediately following deglaciation. This model of “glacial pumping” of a magma-charged lithosphere suggests a causal linkage between volcanism and glaciation in volcanic arcs that explains the persistent observation that the volume and timing of volcanism is correlated with the major climate cycles. © 2020 Elsevier B.V.
关键词	causality Cordilleran Ice Sheet deglaciation eruption-rate glaciovolcanism volcanic arc
英文关键词	Climate models; Hydraulic structures; Monte Carlo methods; Stress analysis; Unloading; Volcanoes; British Columbia , Canada; Deviatoric stress; Dike propagation; Extensional stress; Glacial loadings; Last deglaciation; Tectonic settings; Thin-plate bending; Glacial geology; glaciotectonics; lithosphere; magmatic differentiation; subduction; tectonic setting; volcanic eruption; volcanism; British Columbia; Canada
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202967
作者单位	Volcanology & Petrology Laboratory, Earth Ocean & Atmospheric Science, University of British Columbia, 2020 – 2207 Main Mall, BC, Vancouver, V6T 1Z4, Canada
推荐引用方式 GB/T 7714	Wilson A.M.,Russell J.K.. Glacial pumping of a magma-charged lithosphere: A model for glaciovolcanic causality in magmatic arcs[J],2020,548.
APA	Wilson A.M.,&Russell J.K..(2020).Glacial pumping of a magma-charged lithosphere: A model for glaciovolcanic causality in magmatic arcs.Earth and Planetary Science Letters,548.
MLA	Wilson A.M.,et al."Glacial pumping of a magma-charged lithosphere: A model for glaciovolcanic causality in magmatic arcs".Earth and Planetary Science Letters 548(2020).