| Title | Eroding permafrost coasts release low amounts of dissolved organic carbon (DOC) from ground ice into the nearshore zone of the Arctic Ocean |
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| Author | Tanski, G; Couture, N ; Lantuit, H; Eulenburg, A; Fritz, M |
| Source | Global Biogeochemical Cycles vol. 30, issue 7, 2016 p. 1054-1068, https://doi.org/10.1002/2015GB005337  Open Access |
| Links | Supplementary Data - Données supplémentaires
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| Year | 2016 |
| Alt Series | Earth Sciences Sector, Contribution Series 20160006 |
| Publisher | Wiley-Blackwell |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html; xls |
| Province | Yukon |
| NTS | 117D/03; 117D/04; 117D/05; 117D/06; 117D/11; 117D/12 |
| Area | Arctoc Ocean; Beaufort Sea; Herschel Island; Roland Bay; Kay Point; King Point |
| Lat/Long WENS | -139.5000 -138.0000 69.0667 69.0000 |
| Subjects | environmental geology; marine geology; surficial geology/geomorphology; Nature and Environment; coastal studies; coastal erosion; permafrost; ground ice; organic carbon analyses; marine environments;
nearshore environment; climate effects; sediments; soils; erosion rates; ecosystems; slumps; cores; core samples; glacial features; moraines; lacustrine deposits; biogeochemistry; Climate change; Phanerozoic; Cenozoic; Quaternary |
| Illustrations | location maps; photographs; tables; plots; sketch maps |
| Program | Climate Change Geoscience Coastal Infrastructure |
| Released | 2016 07 13 |
| Abstract | Ice-rich permafrost coasts in the Arctic are highly sensitive to climate warming and erode at a pace that exceeds the global average. Permafrost coasts deliver vast amounts of organic carbon into the
nearshore zone of the Arctic Ocean. Numbers on flux exist for particulate organic carbon (POC) and total or soil organic carbon (TOC, SOC). However, they do not exist for dissolved organic carbon (DOC), which is known to be highly bioavailable. This
study aims to estimate DOC stocks in coastal permafrost as well as the annual flux into the ocean. DOC concentrations in ground ice were analyzed along the ice-rich Yukon coast (YC) in the western Canadian Arctic. The annual DOC flux was estimated
using available numbers for coast length, cliff height, annual erosion rate, and volumetric ice content in different stratigraphic horizons. Our results showed that DOC concentrations in ground ice range between 0.3 and 347.0 mgL-1 with an estimated
stock of 13.6 ± 3.0 gm-3 along the YC. An annual DOC flux of 54.9 ± 0.9 Mgyr-1 was computed. These DOC fluxes are low compared to POC and SOC fluxes from coastal erosion or POC and DOC fluxes from Arctic rivers. We conclude that DOC fluxes from
permafrost coasts play a secondary role in the Arctic carbon budget. However, this DOC is assumed to be highly bioavailable. We hypothesize that DOC from coastal erosion is important for ecosystems in the Arctic nearshore zones, particularly in
summer when river discharge is low, and in areas where rivers are absent. |
| Summary | (Plain Language Summary, not published)
Ice-rich permafrost coasts in the Arctic erode more quickly than the global average, thereby delivering vast amounts of organic carbon to the Arctic
Ocean. Although we know how much particulate organic carbon (POC) is delivered to the ocean, there are no estimates for the flux of dissolved organic carbon (DOC), a type of carbon easily broken down by microbes. Our goal was to estimate how much
DOC is found in ground ice along the Yukon coast and how quickly it is transferred into the ocean. Our results showed that DOC concentrations in ground ice range between 0.3 and 347.0 mg L-1, resulting in an annual flux of 54.4 Mg yr-1. This DOC
flux is low compared to POC fluxes from coastal erosion or POC and DOC fluxes from Arctic rivers and plays a minor role in the Arctic carbon budget. However, this DOC is likely highly decomposable and therefore important for ecosystems in the Arctic
nearshore zones. |
| GEOSCAN ID | 297862 |
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