气候变化领域集成服务门户(CCPortal): Catastrophic glacial-lake outburst flooding of the Patagonian Ice Sheet

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DOI	10.1016/j.earscirev.2019.102996
	Catastrophic glacial-lake outburst flooding of the Patagonian Ice Sheet
	Benito G.; Thorndycraft V.R.
发表日期	2020
ISSN	00128252
卷号	200
英文摘要	Reconstructing the magnitude and timing of catastrophic drainage of proglacial lakes during Late Quaternary deglaciation of palaeo-ice sheets is important for understanding rates of landscape change and regional freshwater forcing of ocean currents. Here, we provide the first detailed reconstruction of catastrophic glacial lake outburst flooding from the Southern Hemisphere, focusing on the Río Baker catchment in central Patagonia. Firstly, we review the evidence for palaeolake drainage events in the Baker catchment showing the basin witnessed a number of events during Late Quaternary deglaciation. These floods helped re-establish the Pacific drainage pathway of the Río Baker by 12.6–11.7 ka, after millennia blocked by ice during the last glaciation. Secondly, we analyse the landform record and flow hydraulics of a catastrophic flood in Patagonia, focusing on the final, Early Holocene, drainage event of Lago General Carrera/Buenos Aires. Using two independent methods, a one-dimensional hydraulic model and dam break simulation, we estimate a minimum peak discharge of 110,000 m3s−1 (0.1 Sv), large enough to form megaflood-type landforms. Using the flow hydrograph, we constrain timing of landform genesis. Eddy bars at the top of the water column (45–65 m above the valley floor) were inundated over 2–36 h following the breach; while tractive bars, formed beneath ∼20 m of water at sites of valley expansion, were flooded for ∼100 h. Raised deltas and palaeoshorelines provide geomorphic evidence for palaeolake drainage events across Patagonia indicating the likely role that catastrophic floods played in continental-scale palaeohydrology and the evolution of fjord ecosystems. © 2019 Elsevier B.V.
关键词	Geomorphology Landscape evolution Megafloods Palaeohydrology South America
英文关键词	catastrophic event; deglaciation; flooding; geomorphology; glacial hydrology; glacial lake; glacial landform; hydrograph; ice sheet; landscape evolution; outburst; paleoflood; paleohydrology; paleolimnology; Quaternary; reconstruction; Southern Hemisphere; Patagonia
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203634
作者单位	Department of Geology, National Museum of Natural Sciences (MNCN), CSIC, Serrano 115 bis, Madrid, 28006, Spain; Department of Geography, Royal Holloway University of London, Egham, TW20 0EX, United Kingdom
推荐引用方式 GB/T 7714	Benito G.,Thorndycraft V.R.. Catastrophic glacial-lake outburst flooding of the Patagonian Ice Sheet[J],2020,200.
APA	Benito G.,&Thorndycraft V.R..(2020).Catastrophic glacial-lake outburst flooding of the Patagonian Ice Sheet.Earth Science Reviews,200.
MLA	Benito G.,et al."Catastrophic glacial-lake outburst flooding of the Patagonian Ice Sheet".Earth Science Reviews 200(2020).