气候变化领域集成服务门户(CCPortal): Holocene glacier and ice cap fluctuations in southwest Greenland inferred from two lake records

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DOI	10.1016/j.quascirev.2020.106529
	Holocene glacier and ice cap fluctuations in southwest Greenland inferred from two lake records
	Larocca L.J.; Axford Y.; Woodroffe S.A.; Lasher G.E.; Gawin B.
发表日期	2020
ISSN	0277-3791
卷号	246
英文摘要	Glaciers and ice caps (GICs) respond rapidly to changes in temperature and precipitation. Thus, records of their past fluctuations yield valuable information on past climate. However, relatively little is known about the long-term, Holocene history of Greenland's local GICs, peripheral to the Greenland Ice Sheet. Here we report sediment records of Holocene glacier activity from two distally fed glacial lakes near Buksefjord, southwest Greenland. The two lakes’ watersheds host modern GICs of contrasting size. The Pers Lake (informal name) watershed drains part (3 km2) of a single small ice cap. In contrast, nearby Lake T3's (informal name) watershed drains numerous GICs totaling 100 km2. At the time it emerged from the sea ∼8.6 ka BP, Pers Lake was receiving no glacial meltwater input. Sediment physical and geochemical properties indicate persistent meltwater input and regrowth of the ice cap within the Pers Lake catchment beginning at ∼1.4 ka BP, after almost 3000 years of sporadic meltwater input beginning ∼4.3 ka BP. The ice cap above Pers Lake reached a maximum late Holocene extent during the final phase of the Little Ice Age (LIA), ∼0.1 ka BP. The complementary Lake T3 sediment record suggests continued meltwater input from the larger suite of upstream GICs from the time of the lake's isolation from the sea ∼8.4–7.5 ka BP through to the present. This indicates that some GICs here probably survived the Holocene Thermal Maximum (HTM), although were significantly reduced in size for an extended period (of unknown age and duration). Combined with evidence from Pers Lake and prior studies that show GICs at low and intermediate elevations in this region melted away completely during the HTM, and evidence for GIC presence at Lake T3, we provide lower and upper bounds on regional HTM equilibrium-line altitudes (ELAs). We estimate that regional ELAs were between ∼1370 and 1470 m above sea level in the early-to-middle Holocene. From the middle to late Holocene, our results, along with other regional GIC studies, indicate progressive lowering of regional glacier ELAs in response to Neoglacial summer cooling of ∼2.7 °C, assuming no change in precipitation. © 2020 Elsevier Ltd
英文关键词	Equilibrium-line altitudes; Glaciers and ice caps; Greenland; Holocene; Isolation basins; Lake sediments; Paleoclimate
语种	英语
scopus关键词	Catchments; Glacial geology; Intercalation; Lakes; Sea level; Sediments; Snow; Watersheds; Equilibrium line altitudes; Geochemical properties; Glacial meltwater; Greenland Ice Sheet; Holocene thermal maximums; Lower and upper bounds; Sediment records; Watershed drains; Ice; catchment; cooling; glacier; Hypsithermal; ice cap; lacustrine environment; Little Ice Age; meltwater; Neoglacial; sea level; watershed; Arctic; Buksefjord; Greenland; Greenland Ice Sheet
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151326
作者单位	Department of Earth and Planetary Sciences, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, United States; Department of Geography, Durham University, Lower Mountjoy South Rd, Durham, DH1 3LE, United Kingdom; Department of Geology and Environmental Science, University of Pittsburgh, 4107 O'Hara Street, Pittsburgh, PA 15260, United States
推荐引用方式 GB/T 7714	Larocca L.J.,Axford Y.,Woodroffe S.A.,et al. Holocene glacier and ice cap fluctuations in southwest Greenland inferred from two lake records[J],2020,246.
APA	Larocca L.J.,Axford Y.,Woodroffe S.A.,Lasher G.E.,&Gawin B..(2020).Holocene glacier and ice cap fluctuations in southwest Greenland inferred from two lake records.Quaternary Science Reviews,246.
MLA	Larocca L.J.,et al."Holocene glacier and ice cap fluctuations in southwest Greenland inferred from two lake records".Quaternary Science Reviews 246(2020).