Contrasting Export of Particulate Organic Carbon From Greenlandic Glacial and Nonglacial Streams
(2022) Geophysical Research Letters — Vol. 49, n° 21, p. 1 (2022)
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- Authors
Bröder, Lisa 
Hirst, Catherine Fouché, J.
- Abstract
- On-going shrinkage of Greenland's icecap, permafrost thaw, and changes in precipitation are exposing its landscapes to erosion and remobilization of ancient organic carbon (OC) held in soils and sedimentary rocks. The fate of this OC and potential feedbacks to climate are still unclear. Here, we show that the glacial Zackenberg river (Northeastern Greenland) exports aged particulate OC (POC, uncalibrated radiocarbon ages of ∼4,000 years). Many of the smaller periglacial streams affected by abrupt permafrost thaw transport substantially older POC (up to 32,000 years), especially with enhanced discharge following intense precipitation. Mineralogical analysis, and density and size fractionation of soils and both glacial and nonglacial river sediments reveal that OC is largely associated with phyllosilicate minerals, suggesting stabilization against microbial processing. Enhanced export of ancient, mineral-associated OC as a consequence of summer rainfall may accelerate translocation of OC from terrestrial to marine environments, but could have limited consequences for climate.
- Affiliations
Swiss Federal Institute of Technology (ETH) Geological Institute, Department of Earth Sciences
Citations
Bröder, L., Hirst, C., Opfergelt, S., Thomas, M., Vonk, J. E., Haghipour, N., Eglinton, T. I., & Fouché, J. (2022). Contrasting Export of Particulate Organic Carbon From Greenlandic Glacial and Nonglacial Streams. Geophysical Research Letters, 49(21), 1. https://doi.org/10.1029/2022gl101210 (Original work published 2022)