G³: Late Cenozoic erosion estimates for the northern Barents Sea: Quantifying glacial sediment input to the Arctic Ocean

The AGU journal G³ Geochemistry, Geophysics, Geosystems has accepted an article authored by Amando Lasabuda (UiT), Wolfram H. Geissler (AWI, Germany), Jan Sverre Laberg (UiT), Stig-Morten Knutsen (NPD, UiT), Tom Arne Rydningen (UiT), and Kai Berglar (BGR, Germany). The paper will appear in the special issue “Polar Region Geosystems” and is titled “Late Cenozoic erosion estimates for the northern Barents Sea: Quantifying glacial sediment input to the Arctic Ocean”.

Key Points:

  • Quantification of the glacial sediment input to the Arctic Ocean from the northwestern Barents Sea
  • For the first time, average erosion and erosion rates are estimated from the source area of this margin using the mass balance approach.
  • These rates are comparable to those reported from other glaciated margin, but only about half compared to the western Barents Sea margin.

Keywords: northwestern Barents Sea, late Cenozoic, glacial erosion, erosion rates

Abstract: 

A compilation of seismic data has been used to characterize the Neogene – Quaternary sedimentary succession of the northwestern Barents Sea continental margin to better understand the paleoenvironmental evolution and the sedimentary processes involved. The Neogene strata are dominated by contourites related to the ocean circulation established from the opening of the Fram Strait connecting the Atlantic and the Arctic Oceans (< ~17.5 Ma). The upper Plio–Pleistocene strata (< ~2.7 Ma) are dominated by stacked gravity-driven deposits forming trough-mouth fans that were sourced from paleo-ice streams. Within the inter-fan areas, contouritic sedimentation prevailed. Thus, this margin provides an example of interaction of glacigenic debris flows, contour currents, and hemipelagic/glacimarine sedimentary processes. A total of ~29,000 km3 of sediments with an average sedimentation rate of about 0.24 m/Kyr were estimated. These numbers reflect the sediment input to this part of the Arctic Ocean from the northwestern Barents Sea shelf and adjacent land areas. For the first time, the average erosion and erosion rates for this source area are estimated using a mass balance approach. Approximately 410 – 650 m of erosion has on average occurred, corresponding to an average erosion rate of ~0.15 – 0.24 m/Kyr. These rates are comparable to those reported from other glaciated margins, including the western Svalbard and mid-Norway margin, but up to only half the rates reported from the western Barents Sea margin. This variation is interpreted due to the size and bedrock types of the drainage area, ice dynamics, and the continental slope gradient.

Reference: 

Lasabuda, A., Geissler, W.H., Laberg, J.S., Knutsen, S.M., Rydningen, T.A., Berglar, K. (2018): Late Cenozoic erosion estimates for the northern Barents Sea: Quantifying glacial sediment input to the Arctic Ocean. Geochemistry, Geophysics, Geosystems, American Geophysical Union, special issue “Polar Region Geosystems”. DOI: 10.1029/2018GC007882 [intranet]