Organic carbon and nitrogen release from coastal erosion on the Bykovsky Peninsula, southern Laptev Sea, Russia

• Main Authors: Lantuit, Hugues, Schirrmeister, Lutz, Fritz, Michael, Wetterich, Sebastian, Grigoriev, Mikhail N., Overduin, Paul, Grosse, Guido, Heim, Birgit, Wegner, Carolyn, Hubberten, Hans-Wolfgang
• Format: Conference Object
• Language: unknown
• Published: University of Lisbon and the University of Évora 2014
• Subjects: Ice; laptev; Laptev Sea; permafrost
• Online Access: https://epic.awi.de/id/eprint/35771/; http://www.eucop4.org/; https://hdl.handle.net/10013/epic.43696

Arctic permafrost coasts are eroding at rates similar or greater than temperate coasts and release large quantities of organic carbon and nitrogen previously stored in permafrost. Estimates of organic carbon fluxes from ice-rich permafrost coasts of the Laptev Sea, where data is scarce, differ widely with estimates varying by two orders or magnitude. Here, we used high resolution datasets on coastal erosion, cryostratigraphy, organic carbon and geomorphology from the Bykovsky Peninsula, in the southern Laptev Sea, to compute below ground organic carbon and nitrogen pools and fluxes of organic carbon from the coast for the current period and the next hundred years. Frozen deposits of the peninsula contain 141.6 Tg of organic carbon, a number 27% lower than what it would contain if the surface had not been affected by permafrost thaw in the past. An additional 44.0 Tg of organic carbon is contained under the peninsula below current sea level. The current fluxes of organic carbon from the peninsula are estimated at 0.058 Tg C a-1 and future fluxes at 0.067 Tg C a-1, or even at 0.085 Tg C a-1 if below sea level organic carbon stocks are included in the calculation. Extrapolation of these measurements to the entire Yedoma coast of the Laptev Sea gives an maximum annual flux of organic carbon from coastal erosion of 6.95 Tg C a-1, which ranges between the previously published minimum and maximum estimations for the same area.s