EGU2020-9393
https://doi.org/10.5194/egusphere-egu2020-9393
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Exploring the Growing Role of Terrestrial Carbon Across North Atlantic Fjords

Craig Smeaton1 and William Austin1,2
Craig Smeaton and William Austin
  • 1University of St-Andrews, Department of Geography & Sustainable Development, St-Andrews, United Kingdom of Great Britain and Northern Ireland (cs244@st-andrews.ac.uk)
  • 2The Scottish Association for Marine Science (SAMS), Oban, Scotland

Fjords are recognized as globally significant hotspots for the burial (Smith et al., 2015) and long-term storage (Smeaton et al., 2017) of marine and terrestrially derived organic carbon (OC). By trapping and locking away OC over geological timescales, fjord sediments provide a potentially important yet largely overlooked climate regulation service. The proximity of fjords to the terrestrial environment in combination with their geomorphology and hydrography results in the fjordic sediments being subsidized with organic carbon (OC) from the terrestrial environment. This terrestrial OC (OCterr) transferred to the marine environment has traditionally be considered lost to the atmosphere in the form of CO2 in most carbon (C) accounting schemes yet globally it is estimated that 55% of OC trapped in fjord sediments is derived from terrestrial sources (Cui et al., 2016). So is this terrestrial OC truly lost? Here, we estimate the quantity of OCterr held within North Atlantic fjords with the aim of better understanding the recent and long-term role of the terrestrial environment in the evolution of these globally significant sedimentary OC stores. By understanding this subsidy of OC from the terrestrial to the marine environment we can take the first steps in quantifying the terrestrial OC stored in fjords and the wider coastal marine environment.

Cui, X., Bianchi, T.S., Savage, C. and Smith, R.W., 2016. Organic carbon burial in fjords: Terrestrial versus marine inputs. Earth and Planetary Science Letters451, pp.41-50.

Smeaton, C., Austin, W.E., Davies, A., Baltzer, A., Howe, J.A. and Baxter, J.M., 2017. Scotland's forgotten carbon: a national assessment of mid-latitude fjord sedimentary stocks. Biogeosciences.

Smith, R.W., Bianchi, T.S., Allison, M., Savage, C. and Galy, V., 2015. High rates of organic carbon burial in fjord sediments globally. Nature Geoscience8(6), p.450.

 

How to cite: Smeaton, C. and Austin, W.: Exploring the Growing Role of Terrestrial Carbon Across North Atlantic Fjords, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9393, https://doi.org/10.5194/egusphere-egu2020-9393, 2020