气候变化领域集成服务门户(CCPortal): Enhanced trace element mobilization by Earth's ice sheets

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DOI	10.1073/pnas.2014378117
	Enhanced trace element mobilization by Earth's ice sheets
	Hawkings J.R.; Skidmore M.L.; Wadham J.L.; Priscu J.C.; Morton P.L.; Hatton J.E.; Gardner C.B.; Kohler T.J.; Stibal M.; Bagshaw E.A.; Steigmeyer A.; Barker J.; Dore J.E.; Berry Lyons W.; Tranter M.; Spencer R.G.M.; SALSA Science Team
发表日期	2020
ISSN	0027-8424
起始页码	31648
结束页码	31659
卷号	117 期号:50
英文摘要	Trace elements sustain biological productivity, yet the significance of trace element mobilization and export in subglacial runoff from ice sheets is poorly constrained at present. Here, we present size-fractionated (0.02, 0.22, and 0.45 μm) concentrations of trace elements in subglacial waters from the Greenland Ice Sheet (GrIS) and the Antarctic Ice Sheet (AIS). Concentrations of immobile trace elements (e.g., Al, Fe, Ti) far exceed global riverine and open ocean mean values and highlight the importance of subglacial aluminosilicate mineral weathering and lack of retention of these species in sediments. Concentrations are higher from the AIS than the GrIS, highlighting the geochemical consequences of prolonged water residence times and hydrological isolation that characterize the former. The enrichment of trace elements (e.g., Co, Fe, Mn, and Zn) in subglacial meltwaters compared with seawater and typical riverine systems, together with the likely sensitivity to future ice sheet melting, suggests that their export in glacial runoff is likely to be important for biological productivity. For example, our dissolved Fe concentration (20,900 nM) and associated flux values (1.4 Gmol y−1) from AIS to the Fe-deplete Southern Ocean exceed most previous estimates by an order of magnitude. The ultimate fate of these micronutrients will depend on the reactivity of the dominant colloidal size fraction (likely controlled by nanoparticulate Al and Fe oxyhydroxide minerals) and estuarine processing. We contend that ice sheets create highly geochemically reactive particulates in subglacial environments, which play a key role in trace elemental cycles, with potentially important consequences for global carbon cycling. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Biogeochemical cycles; Elemental cycles; Ice sheets; Southern Ocean; Trace elements
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160190
作者单位	Hawkings, J.R., National High Magnetic Field Laboratory Geochemistry Group, Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL 32306, United States, Interface Geochemistry, German Research Centre for Geosciences (GFZ), Potsdam, 14473, Germany; Skidmore, M.L., Department of Earth Sciences, Montana State University, Bozeman, MT 59717, United States; Wadham, J.L., School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, United Kingdom; Priscu, J.C., Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, United States; Morton, P.L., National High Magnetic Field Laboratory Geochemistry Group, Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL 32306, United States; Hatton, J.E., School of Earth Sciences, University of Bristol, Bristol, BS8 1RL, United Kingdom; Gardner, C.B., School of Earth Sciences, Byrd Polar and Climate Research Center, Ohio State Univers...
推荐引用方式 GB/T 7714	Hawkings J.R.,Skidmore M.L.,Wadham J.L.,et al. Enhanced trace element mobilization by Earth's ice sheets[J],2020,117(50).
APA	Hawkings J.R..,Skidmore M.L..,Wadham J.L..,Priscu J.C..,Morton P.L..,...&SALSA Science Team.(2020).Enhanced trace element mobilization by Earth's ice sheets.Proceedings of the National Academy of Sciences of the United States of America,117(50).
MLA	Hawkings J.R.,et al."Enhanced trace element mobilization by Earth's ice sheets".Proceedings of the National Academy of Sciences of the United States of America 117.50(2020).