Universität zu Köln

Hatton, Jade E., Hendry, Katharine R., Hirst, Catherine, Opfergelt, Sophie, Henkel, Susann, Silva-Busso, Adrian, Welch, Susan A., Wadham, Jemma L., Lyons, W. Berry, Bagshaw, Elizabeth, Staubwasser, Michael and McKnight, Diane M. (2020). Silicon Isotopic Composition of Dry and Wet-Based Glaciers in Antarctica. Front. Earth Sci., 8. LAUSANNE: FRONTIERS MEDIA SA. ISSN 2296-6463

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Abstract

Glaciers and ice sheets export significant amounts of silicon (Si) to downstream ecosystems, impacting local and potentially global biogeochemical cycles. Recent studies have shown Si in Arctic glacial meltwaters to have an isotopically distinct signature when compared to non-glacial rivers. This is likely linked to subglacial weathering processes and mechanochemical reactions. However, there are currently no silicon isotope (delta Si-30) data available from meltwater streams in Antarctica, limiting the current inferences on global glacial silicon isotopic composition and its drivers. To address this gap, we present dissolved silicon (DSi), delta Si-30(DSi), and major ion data from meltwater streams draining a polythermal glacier in the region of the West Antarctic Peninsula (WAP; King George Island) and a cold-based glacier in East Antarctica [Commonwealth Stream, McMurdo Dry Valleys (MDV)]. These data, alongside other global datasets, improve our understanding of how contrasting glacier thermal regime can impact upon Si cycling and therefore the delta(30)Si(DSi)composition. We find a similar delta(30)Si(DSi)composition between the two sites, with the streams on King George Island varying between -0.23 and +1.23 parts per thousand and the Commonwealth stream varying from -0.40 to +1.14 parts per thousand. However, meltwater streams in King George Island have higher DSi concentrations, and the two glacial systems exhibit opposite DSi - delta(30)Si(DSi)trends. These contrasts likely result from differences in weathering processes, specifically the role of subglacial processes (King George Island) and, supraglacial processes followed by in-stream weathering in hyporheic zones (Commonwealth Stream). These findings are important when considering likely changes in nutrient fluxes from Antarctic glaciers under climatic warming scenarios and consequent shifts in glacial thermal regimes.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Hatton, Jade E. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hendry, Katharine R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Hirst, Catherine UNSPECIFIED UNSPECIFIED UNSPECIFIED Opfergelt, Sophie UNSPECIFIED UNSPECIFIED UNSPECIFIED Henkel, Susann UNSPECIFIED UNSPECIFIED UNSPECIFIED Silva-Busso, Adrian UNSPECIFIED UNSPECIFIED UNSPECIFIED Welch, Susan A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wadham, Jemma L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Lyons, W. Berry UNSPECIFIED UNSPECIFIED UNSPECIFIED Bagshaw, Elizabeth UNSPECIFIED UNSPECIFIED UNSPECIFIED Staubwasser, Michael UNSPECIFIED UNSPECIFIED UNSPECIFIED McKnight, Diane M. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-326389
DOI:	10.3389/feart.2020.00286
Journal or Publication Title:	Front. Earth Sci.
Volume:	8
Date:	2020
Publisher:	FRONTIERS MEDIA SA
Place of Publication:	LAUSANNE
ISSN:	2296-6463
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language KING-GEORGE ISLAND; GREENLAND ICE-SHEET; TAYLOR VALLEY; MELTWATER STREAMS; HYPORHEIC EXCHANGE; CRYOCONITE HOLES; DISSOLVED-LOAD; CLIMATE-CHANGE; IRON; GEOCHEMISTRY Multiple languages Geosciences, Multidisciplinary Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/32638