| Titre | Coastal Erosion of Permafrost Soils along the Yukon Coastal Plain and Fluxes of Organic Carbon to the Canadian Beaufort Sea |
| Auteur | Couture, N J; Irrgang, A; Pollard, W; Lantuit, H; Fritz, M |
| Source | Journal of Geophysical Research, Biogeosciences vol. 123, issue 2, 2018 p. 406-422, https://doi.org/10.1002/2017JG004166 (Accès ouvert) |
| Année | 2018 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20170202 |
| Éditeur | Wiley-Blackwell |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1002/2017JG004166 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Yukon; Territoires du Nord-Ouest |
| SNRC | 107B; 117A; 117D |
| Lat/Long OENS | -141.0000 -138.0000 69.6667 69.0000 |
| Sujets | études côtières; érosion côtière; milieu côtièr; carbone; carbone organique; pergélisol; glace fossile; fentes de glace; polygones de fente de glace; débit de sedimentation; géologie des dépôts
meubles/géomorphologie |
| Illustrations | location maps; tables |
| Programme | Division de la CGC du nord du Canada, Environnement et hydrogéologie du Nord |
| Diffusé | 2018 02 17 |
| Résumé | (disponible en anglais seulement)
Reducing uncertainties about carbon cycling is important in the Arctic where rapid environmental changes contribute to enhanced mobilization of carbon. Here we
quantify soil organic carbon (SOC) contents of permafrost soils along the Yukon Coastal Plain and determine the annual fluxes from coastal erosion. Different terrain units were assessed based on surficial geology, morphology, and ground ice
conditions. To account for the volume of wedge ice and massive ice in a unit, SOC contents were reduced by 19% and sediment contents by 16%. The SOC content in a 1 m2 column of soil varied according to the height of the bluff, ranging from 30 to 662
kg, with a mean value of 183 kg. Forty-four per cent of the SOC was within the top 1 m of soil and values varied based on surficial materials, ranging from 30 to 53 kg C/m3, with a mean of 41 kg. Eighty per cent of the shoreline was erosive with a
mean annual rate of change of ?0.7 m/yr. This resulted in a SOC flux per meter of shoreline of 132 kg C/m/yr, and a total flux for the entire 282 km of the Yukon coast of 35.5 × 106 kg C/yr (0.036 Tg C/yr). The mean flux of sediment per meter of
shoreline was 5.3 × 103 kg/m/yr, with a total flux of 1,832 × 106 kg/yr (1.832 Tg/yr). Sedimentation rates indicate that approximately 13% of the eroded carbon was sequestered in nearshore sediments, where the overwhelming majority of organic carbon
was of terrestrial origin. |
| Résumé | (Résumé en langage clair et simple, non publié et disponible en anglais seulement)
The oceans help slow the buildup of atmospheric CO2 because they absorb much of it. However if carbon from
other sources is added to the oceans, it reduces their ability to absorb CO2. We examine the organic carbon (OC) added to the Beaufort Sea from eroding permafrost along the Yukon coast. Understanding carbon cycling is important because environmental
changes in the Arctic such as longer open water seasons, rising sea levels, and warmer temperatures can increase coastal erosion and thus carbon fluxes to the sea. We measured the OC in soils and applied corrections to account for the volume taken up
by ground ice. By determining how quickly the coast is eroding, we assessed how much OC is being transferred to the ocean. Our results show that 35 million kilograms of carbon is added annually from this section of the coast. If we extrapolate these
results to other coastal areas along the Canadian Beaufort Sea, the flux of organic carbon is nearly three times what was previously thought. |
| GEOSCAN ID | 305969 |
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