气候变化领域集成服务门户(CCPortal): Tectonic controls on rates and spatial patterns of glacial erosion through geothermal heat flux

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DOI	10.1016/j.epsl.2020.116348
	Tectonic controls on rates and spatial patterns of glacial erosion through geothermal heat flux
	Lai J.; Anders A.M.
发表日期	2020
ISSN	0012821X
卷号	543
英文摘要	Glacial erosion has shaped many mountain belts during the cold periods of the Late Cenozoic. The rate of glacial erosion is sensitive to the subglacial environment, including both the subglacial hydrology and the basal thermal regime. Geothermal heat from underlying bedrock is a major contributor to glacier energy budgets, controlling ice dynamics at the ice-bed interface by changing the basal temperature and the supply of meltwater. Despite the known influence of geothermal heat on the subglacial environment, its impact on glacial erosion has received little study. The geothermal heat flux in glaciated mountain ranges varies widely as a function of the tectonic setting. Therefore, if glacial erosion is sensitive to geothermal heat flux, the evolution of glaciated landscapes may depend upon tectonically-controlled geothermal gradients. We explore the impact of geothermal heat flux on the rates and spatial patterns of glacial erosion in mountain ranges using numerical models. We couple a sliding-dependent glacial erosion model with the Parallel Ice Sheet Model (PISM) to simulate the evolution of a synthetic glacial landscape. We find a robust tendency for increasing glacial erosion with increasing geothermal heat flux. The spatial pattern of erosion also varies with the magnitude of geothermal heat flux. At low geothermal heat flux, glacial erosion is consistently focused in major valleys. As geothermal heat flux increases, the area of significant glacial erosion expands into higher elevations and the rate of erosion increases. The location of maximum erosion migrates up-valley as geothermal heat flux increases, suggesting that glacial erosion tends to produce distinct landscapes as a function of geothermal heat flux. Our finding suggests that active mountain belts with high geothermal heat flux will express the glacial buzzsaw effect, in which high elevation topography is preferentially removed by glacial erosion. Glaciers at passive margins with low geothermal heat flux, in contrast, will tend to incise deep valleys at relatively low elevations. Previous work on the interaction between tectonics and landscape evolution has focused on relief generation and fracturing of rocks. Our results introduce a novel potential linkage between tectonics and erosion based on the sensitivity of glacial erosion to geothermal heat. © 2020 Elsevier B.V.
关键词	geothermal heat glacial erosion landscape evolution numerical modeling
英文关键词	Budget control; Erosion; Geothermal energy; Geothermal heating; Glacial geology; Ice; Landforms; Tectonics; Topography; Basal temperature; Geothermal gradients; Glacial landscapes; Ice sheet models; Subglacial hydrology; Tectonic control; Tectonic settings; Tectonics and landscape evolutions; Heat flux; geothermal gradient; glacial erosion; heat flux; ice sheet; mountain region; numerical model; spatial variation; tectonic setting; tectonics
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/202712
作者单位	Department of Geology, University of Illinois at Urbana-Champaign, United States
推荐引用方式 GB/T 7714	Lai J.,Anders A.M.. Tectonic controls on rates and spatial patterns of glacial erosion through geothermal heat flux[J],2020,543.
APA	Lai J.,&Anders A.M..(2020).Tectonic controls on rates and spatial patterns of glacial erosion through geothermal heat flux.Earth and Planetary Science Letters,543.
MLA	Lai J.,et al."Tectonic controls on rates and spatial patterns of glacial erosion through geothermal heat flux".Earth and Planetary Science Letters 543(2020).