loading page

How turbidity currents dictate organic carbon fluxes across river-fed fjords
  • +18
  • Sophie Hage,
  • Valier Galy,
  • Matthieu J.B. Cartigny,
  • Catharina Heerema,
  • Maarten S Heijnen,
  • Sanem Acikalin,
  • Michael Andrew Clare,
  • Ian J W Giesbrecht,
  • Darren Richard Gröcke,
  • Alison Hendry,
  • Robert George Hilton,
  • Stephen M Hubbard,
  • James Edward Hunt,
  • Gwyn Lintern,
  • Claire McGhee,
  • Daniel R. Parsons,
  • Ed L Pope,
  • Cooper D Stacey,
  • Esther Joanne Sumner,
  • Suzanne Tank,
  • Peter Talling
Sophie Hage
Univ Brest, CNRS, Ifremer, Geo-Ocean, Univ Brest, CNRS, Ifremer, Geo-Ocean

Corresponding Author:[email protected]

Author Profile
Valier Galy
woods hole oceanographic institution, woods hole oceanographic institution
Author Profile
Matthieu J.B. Cartigny
University of Durham, University of Durham
Author Profile
Catharina Heerema
Durham University, Durham University
Author Profile
Maarten S Heijnen
National Oceanography Centre Southampton, National Oceanography Centre Southampton
Author Profile
Sanem Acikalin
Newcastle University, Newcastle University
Author Profile
Michael Andrew Clare
National Oceanography Centre Southampton, National Oceanography Centre Southampton
Author Profile
Ian J W Giesbrecht
Hakai Institute and Simon Fraser University, Hakai Institute and Simon Fraser University
Author Profile
Darren Richard Gröcke
University of Durham, University of Durham
Author Profile
Alison Hendry
Newcastle University, Newcastle University
Author Profile
Robert George Hilton
Durham University, Durham University
Author Profile
Stephen M Hubbard
University of Calgary, University of Calgary
Author Profile
James Edward Hunt
National Oceanography Centre, Southampton, National Oceanography Centre, Southampton
Author Profile
Gwyn Lintern
Geological Survey of Canada, Institute of Ocean Science, Geological Survey of Canada, Institute of Ocean Science
Author Profile
Claire McGhee
University of Newcastle, University of Newcastle
Author Profile
Daniel R. Parsons
University of Hull, University of Hull
Author Profile
Ed L Pope
Durham University, Durham University
Author Profile
Cooper D Stacey
Geological Survey of Canada, Geological Survey of Canada
Author Profile
Esther Joanne Sumner
University of Southampton, University of Southampton
Author Profile
Suzanne Tank
University of Alberta, University of Alberta
Author Profile
Peter Talling
University of Durham, U.K., University of Durham, U.K.
Author Profile

Abstract

The delivery and burial of terrestrial particulate organic carbon (OC) in marine sediments is important to quantify, because this OC is a food resource for benthic communities, and if buried it may lower the concentrations of atmospheric CO2 over geologic timescales. Analysis of sediment cores has previously shown that fjords are hotspots for OC burial. Fjords can contain complex networks of submarine channels formed by seafloor sediment flows, called turbidity currents. However, the burial efficiency and distribution of OC by turbidity currents in river-fed fjords had not been investigated previously. Here, we determine OC distribution and burial efficiency across a turbidity current system within a fjord, in Bute Inlet (Canada). We show that 60 ± 10 % of the OC supplied by the two river sources, is buried across the fjord surficial (2 m) sediment. The sand-dominated submarine channel and its terminal lobe contain 63 ± 14 % of the annual terrestrial OC burial in the fjord. In contrast, the muddy overbank and distal flat basin settings contain the remaining 37 ± 14 %. OC in the channel, lobe and overbank exclusively comprises terrestrial OC sourced from rivers. When normalized by the fjord’s surface area, at least three times more terrestrial OC is buried in Bute Inlet, compared to the muddy parts of other fjords previously studied. Although the long-term (>100 year) preservation of this OC is still to be fully understood, turbidity currents in fjords appear to be efficient in storing OC supplied by rivers in their near-surface deposits.