气候变化领域集成服务门户(CCPortal): Glacier extent and climate in the Maritime Alps during the Younger Dryas

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DOI	10.1016/j.palaeo.2019.109400
	Glacier extent and climate in the Maritime Alps during the Younger Dryas
	Spagnolo M.; Ribolini A.
发表日期	2019
ISSN	0031-0182
卷号	536
英文摘要	This study focuses on an Egesen-stadial moraine located at 1906–1920 m asl in the NE Maritime Alps, Europe. Three moraine boulders are dated, via cosmogenic isotope analyses, to 12,490 ± 1120, 12,260 ± 1220 and 13,840 ± 1240 yr, an age compatible with the Younger Dryas cooling event. The reconstructed glacier that deposited the moraine has an equilibrium line altitude of 2349 ± 5 m asl, calculated with an Accumulation Area Balance Ratio of 1.6. The result is very similar to the equilibrium line altitude of another reconstructed glacier that deposited a moraine also dated to Younger Dryas, in the SW Maritime Alps. The similarity suggests comparable climatic conditions across the region during the cooling event. The Younger Dryas palaeoprecipitation is 1549 ± 26 mm/yr, calculated using the empirical law that links precipitation and temperature at a glacier equilibrium line altitude, with palaeotemperatures obtained from nearby palynological and chironomids studies. The palaeoprecipitation is similar to the present, thus indicating non-arid conditions during the Younger Dryas. This is probably due to the Maritime Alps peculiar position, at the crossroads between air masses from the Mediterranean and the North Atlantic, the latter displaced by the southward migration of the polar front. The equilibrium line altitude interval defined by the two reconstructed glaciers, is used to model the extent of another 66 potential Younger Dryas glaciers in the region. Each modelled glacier is reconstructed by iteratively changing the position of its front until the reconstructed glacier has an ELA that falls within the interval. The result, which is checked against geomorphological evidence, shows that glaciers covered 83.74 km2 during the Younger Dryas, with a volume of 5.39 km3. All valley heads were occupied by ice, except for the Maddalena/Larche Pass (1999 m asl), an ideal site for future archaeological, palaeoecological and palaeozoological studies. © 2019 Elsevier B.V.
英文关键词	Cosmogenic dates; Equilibrium Line Altitude; Glacier reconstruction; Maritime Alps; Palaeoclimate; Younger Dryas
语种	英语
scopus关键词	air mass; altitude; cooling; cosmogenic radionuclide; equilibrium line; glacier advance; moraine; paleoclimate; palynology; reconstruction; Younger Dryas; Alps; Atlantic Ocean; Atlantic Ocean (North); Maritime Alps; Western Alps; Chironomidae
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150761
作者单位	School of Geosciences, University of Aberdeen, United Kingdom; Dipartimento di Scienze Della Terra, Universita’ di Pisa, Italy
推荐引用方式 GB/T 7714	Spagnolo M.,Ribolini A.. Glacier extent and climate in the Maritime Alps during the Younger Dryas[J],2019,536.
APA	Spagnolo M.,&Ribolini A..(2019).Glacier extent and climate in the Maritime Alps during the Younger Dryas.Palaeogeography, Palaeoclimatology, Palaeoecology,536.
MLA	Spagnolo M.,et al."Glacier extent and climate in the Maritime Alps during the Younger Dryas".Palaeogeography, Palaeoclimatology, Palaeoecology 536(2019).