Publication Date:
2017-10-26
Description:
We describe the evolution of coastal retrogressive thaw slumps (RTSs) between 1952 and 2011 along the Yukon Coast, Canada, and provide the first estimate of the contribution of RTSs to the nearshore organic carbon budget in this area. We 1) monitor the evolution of RTSs during the periods 1952–1972 and 1972–2011; 2) calculate the volume of material eroded and stocks of organic carbon (OC) mobilized through slumping – including soil organic carbon (SOC) and dissolved organic carbon (DOC) – and 3) measure the OC fluxes mobilized through slumping between 1972 and 2011. We identified 15 RTSs using high-resolution satellite imagery from 2011 and geocoded aerial photographs from 1952 and 1972. To estimate the volume of eroded material, we applied a spline interpolation on an airborne LiDAR dataset acquired in July 2013. We inferred the stocks of mobilized SOC and DOC from existing related literature. Our results show a 73 % increase in the number of RTSs between 1952 and 2011. In the study area, RTSs displaced at least 8600 × 103 m3 of material, with 53 % of ice. We estimated that slumping mobilized 81 900 × 103 kg of SOC and 156 × 103 kg of DOC. Since 1972, 17 % of the RTSs 20 have displaced 8.6 × 103 m3/yr of material, with an average OC flux of 82.5 ×103 kg/yr. This flux represents 0.3 % of the OC flux released from coastal retreat; however RTSs have a strong impact on the transformation of OC in the coastal fringe.
Print ISSN:
1810-6277
Electronic ISSN:
1810-6285
Topics:
Biology
,
Geosciences
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