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Preservation of terrestrial organic carbon in marine sediments offshore Taiwan: mountain building and atmospheric carbon dioxide sequestration
- Source :
- Earth Surface Dynamics, Earth Surface Dynamics (2196-6311) (Copernicus Gesellschaft Mbh), 2014-03-04, Vol. 2, N. 1, P. 127-139, Kao, S-J, Hilton, R G, Selvaraj, K, Dai, M, Zehetner, F, Huang, J-C, Hsu, S-C, Sparkes, R, Liu, J T, Lee, T-Y, Yang, J-Y T, Galy, A, Xu, X & Hovius, N 2014, ' Preservation of terrestrial organic carbon in marine sediments offshore Taiwan: mountain building and atmospheric carbon dioxide sequestration ', Earth Surface Dynamics, vol. 2, no. 1, pp. 127-139 . https://doi.org/10.5194/esurf-2-127-2014, Earth surface dynamics, 2014, Vol.2(1), pp.127-139 [Peer Reviewed Journal], Earth Surface Dynamics, Vol 2, Iss 1, Pp 127-139 (2014)
- Publication Year :
- 2018
-
Abstract
- Geological sequestration of atmospheric carbon dioxide (CO2) can be achieved by the erosion of organic carbon (OC) from the terrestrial biosphere and its burial in long-lived marine sediments. Rivers on mountain islands of Oceania in the western Pacific have very high rates of OC export to the ocean, yet its preservation offshore remains poorly constrained. Here we use the OC content (Corg, %), radiocarbon (Δ 14Corg) and stable isotope (δ13Corg) composition of sediments offshore Taiwan to assess the fate of terrestrial OC, using surface, sub-surface and Holocene sediments. We account for rock-derived OC to assess the preservation of OC eroded from the terrestrial biosphere and the associated CO2 sink during flood discharges (hyperpycnal river plumes) and when river inputs are dispersed more widely (hypopycnal). The Corg, Δ14Corg and δ 13Corg of marine sediment traps and cores indicate that during flood discharges, terrestrial OC can be transferred efficiently down submarine canyons to the deep ocean and accumulates offshore with little evidence for terrestrial OC loss. In marine sediments fed by dispersive river inputs, the Corg, Δ14Corg and δ 13Corg are consistent with mixing of terrestrial OC with marine OC and suggest that efficient preservation of terrestrial OC (>70%) is also associated with hypopycnal delivery. Sub-surface and Holocene sediments indicate that this preservation is long-lived on millennial timescales. Re-burial of rock-derived OC is pervasive. Our findings from Taiwan suggest that erosion and offshore burial of OC from the terrestrial biosphere may sequester >8 TgC yr−1 across Oceania, a significant geological CO2 sink which requires better constraint. We postulate that mountain islands of Oceania provide a strong link between tectonic uplift and the carbon cycle, one moderated by the climatic variability which controls terrestrial OC delivery to the ocean.
- Subjects :
- Total organic carbon
geography
Carbon dioxide in Earth's atmosphere
geography.geographical_feature_category
lcsh:Dynamic and structural geology
010504 meteorology & atmospheric sciences
Biosphere
Submarine canyon
15. Life on land
010502 geochemistry & geophysics
01 natural sciences
Deep sea
Sink (geography)
Carbon cycle
law.invention
Geophysics
Oceanography
lcsh:QE500-639.5
13. Climate action
law
14. Life underwater
Radiocarbon dating
Geology
0105 earth and related environmental sciences
Earth-Surface Processes
Subjects
Details
- Language :
- English
- ISSN :
- 2196632X
- Database :
- OpenAIRE
- Journal :
- Earth Surface Dynamics, Earth Surface Dynamics (2196-6311) (Copernicus Gesellschaft Mbh), 2014-03-04, Vol. 2, N. 1, P. 127-139, Kao, S-J, Hilton, R G, Selvaraj, K, Dai, M, Zehetner, F, Huang, J-C, Hsu, S-C, Sparkes, R, Liu, J T, Lee, T-Y, Yang, J-Y T, Galy, A, Xu, X & Hovius, N 2014, ' Preservation of terrestrial organic carbon in marine sediments offshore Taiwan: mountain building and atmospheric carbon dioxide sequestration ', Earth Surface Dynamics, vol. 2, no. 1, pp. 127-139 . https://doi.org/10.5194/esurf-2-127-2014, Earth surface dynamics, 2014, Vol.2(1), pp.127-139 [Peer Reviewed Journal], Earth Surface Dynamics, Vol 2, Iss 1, Pp 127-139 (2014)
- Accession number :
- edsair.doi.dedup.....bb4c44851b5b94f0d6fd7641c6dee64d