气候变化领域集成服务门户(CCPortal): Geochemistry of Contrasting Stream Types, Taylor Valley, Antarctica

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DOI	10.1130/B35479.1
	Geochemistry of Contrasting Stream Types, Taylor Valley, Antarctica
	Harmon R.S.; Leslie D.L.; Lyons W.B.; Welch K.A.; McKnight D.M.
发表日期	2020
ISSN	167606
起始页码	425
结束页码	448
卷号	133
英文摘要	The McMurdo Dry Valley region is the largest ice-free area of Antarctica. Ephemeral streams flow here during the austral summer, transporting glacial meltwater to perennially ice-covered, closed basin lakes. The chemistry of 24 Taylor Valley streams was examined over the two-decade period of monitoring from 1993 to 2014, and the geochemical behavior of two streams of contrasting physical and biological character was monitored across the seven weeks of the 2010–2011 flow season. Four species dominate stream solute budgets: HCO3 –, Ca2+, Na+, and Cl–, with SO4 2–, Mg2+, and K+ present in significantly lesser proportions. All streams contain dissolved silica at low concentrations. Across Taylor Valley, streams are characterized by their consistent anionic geochemical fingerprint of HCO3 > Cl > SO4, but there is a split in cation composition between 14 streams with Ca > Na > Mg > K and 10 streams with Na > Ca > Mg > K. Andersen Creek is a first-order proglacial stream representative of the 13 short streams that flow <1.5 km from source to gage. Von Guerard is representative of 11 long streams 2–7 km in length characterized by extensive hyporheic zones. Both streams exhibit a strong daily cycle for solute load, temperature, dissolved oxygen, and pH, which vary in proportion to discharge. A well-expressed diurnal co-variation of pH with dissolved oxygen is observed for both streams that reflects different types of biological control. The relative consistency of Von Guerard composition over the summer flow season reflects chemostatic regulation, where water in transient storage introduced during times of high streamflow has an extended opportunity for water-sediment interaction, silicate mineral dissolution, and pore-water exchange. © 2020 Geological Society of America
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184771
作者单位	Department of Marine Earth and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695, United States; Department of Earth Sciences, University of Memphis, Memphis, Tennessee 38152, United States; School of Earth Sciences and Byrd Polar and Climate Research Center, Ohio State University, Columbus, Ohio 423210, United States; Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado 80309, United States
推荐引用方式 GB/T 7714	Harmon R.S.,Leslie D.L.,Lyons W.B.,et al. Geochemistry of Contrasting Stream Types, Taylor Valley, Antarctica[J],2020,133.
APA	Harmon R.S.,Leslie D.L.,Lyons W.B.,Welch K.A.,&McKnight D.M..(2020).Geochemistry of Contrasting Stream Types, Taylor Valley, Antarctica.Bulletin of the Geological Society of America,133.
MLA	Harmon R.S.,et al."Geochemistry of Contrasting Stream Types, Taylor Valley, Antarctica".Bulletin of the Geological Society of America 133(2020).