气候变化领域集成服务门户(CCPortal): (Appendix A) Geochemical composition of snow and eolian mineral dust from Berkner Island ice sheet, Antarctica

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DOI	https://doi.org/10.1594/PANGAEA.786617
	(Appendix A) Geochemical composition of snow and eolian mineral dust from Berkner Island ice sheet, Antarctica
	Bory; Aloys J-M; Wolff; Eric W; Mulvaney; Robert; Jagoutz; Emil; Wegner; Anna; Ruth; Urs; Elderfield; Henry
发布日期	2010-07-27
数据集类型	dataset
英文关键词	ipy
英文简介	The Sr and Nd isotopic composition of dust extracted from recent snow layers at the top of Berkner Island ice sheet (located within the Filchner-Ronne Ice Shelf at the southern end of the Weddell Sea) enables us, for the first time, to document dust provenance in Antarctica outside the East Antarctic Plateau (EAP) where all previous studies based on isotopic fingerprinting were carried out. Berkner dust displays an overall crust-like isotopic signature, characterized by more radiogenic 87Sr/86Sr and much less radiogenic 143Nd/144Nd compared to dust deposited on the EAP during glacial periods. Differences with EAP interglacial dust are not as marked but still significant, indicating that present-day Berkner dust provenance is distinct, at least to some extent, from that of the dust reaching the EAP. The fourteen snow-pit sub-seasonal samples that were obtained span a two-year period (2002-2003) and their dust Sr and Nd isotopic composition reveals that multiple sources are at play over a yearly time period. Southern South America, Patagonia in particular, likely accounts for part of the observed spring/summer dust deposition maxima, when isotopic composition is shifted towards 'younger' isotopic signatures. In the spring, possible additional inputs from Australian sources would also be supported by the data. Most of the year, however, the measured isotopic signatures would be best explained by a sustained background supply from putative local sources in East Antarctica, which carry old-crust-like isotopic fingerprints. Whether the restricted East Antarctic ice-free areas produce sufficient eolian material has yet to be substantiated however. The fact that large (> 5 µm) particles represent a significant fraction of the samples throughout the entire time-series supports scenarios that involve contributions from proximal sources, either in Patagonia and/or Antarctica (possibly including snow-free areas in the Antarctic Peninsula and other areas as well). This also indicates that additional dust transport, which does not reach the EAP, must occur at low-tropospheric levels to this coastal sector of Antarctica.
空间范围	Latitude: -79.566700 * Longitude: -45.650000
时间范围	2003-12-01T00:00:00 - 2003-12-01T00:00:00
语种	英语
国家	国际
学科大类	气候变化
学科子类	冰冻圈
文献类型	数据集
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/213790
推荐引用方式 GB/T 7714	Bory,Aloys J-M,Wolff,et al. (Appendix A) Geochemical composition of snow and eolian mineral dust from Berkner Island ice sheet, Antarctica.2010-07-27.https://doi.org/10.1594/PANGAEA.786617.