Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1073/pnas.2014378117 |
Enhanced trace element mobilization by Earth’s ice sheets | |
Jon R. Hawkings; Mark L. Skidmore; Jemma L. Wadham; John C. Priscu; Peter L. Morton; Jade E. Hatton; Christopher B. Gardner; Tyler J. Kohler; Marek Stibal; Elizabeth A. Bagshaw; August Steigmeyer; Joel Barker; John E. Dore; W. Berry Lyons; Martyn Tranter; Robert G. M. Spencer; the SALSA Science Team | |
2020-11-23 | |
发表期刊 | Proceedings of the National Academy of Science |
出版年 | 2020 |
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. |
领域 | 地球科学 |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/304847 |
专题 | 地球科学 |
推荐引用方式 GB/T 7714 | Jon R. Hawkings,Mark L. Skidmore,Jemma L. Wadham,等. Enhanced trace element mobilization by Earth’s ice sheets[J]. Proceedings of the National Academy of Science,2020. |
APA | Jon R. Hawkings.,Mark L. Skidmore.,Jemma L. Wadham.,John C. Priscu.,Peter L. Morton.,...&the SALSA Science Team.(2020).Enhanced trace element mobilization by Earth’s ice sheets.Proceedings of the National Academy of Science. |
MLA | Jon R. Hawkings,et al."Enhanced trace element mobilization by Earth’s ice sheets".Proceedings of the National Academy of Science (2020). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论