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On October 22, 2024, 5:05:52 PM UTC, Gravatar ckan_admin:

  • Updated description of ADCP data Whittard Canyon 64PE453-53 from

    This dataset covers ADCP data collected in Whittard Canyon at 2200 m water depth. THe 75 kHz ADCP was upward looking and deployed in Whittard to monitor daily to seasonal changes in current speed and acoustic backscatter. Challenging the highstand-dormant paradigm for land-detached submarine canyons (Heijnen et al.): Abstract: Sediment, nutrients, organic carbon and pollutants are funnelled down submarine canyons from continental shelves by sediment-laden flows called turbidity currents, which dominate particulate transfer to the deep sea. Post-glacial sea-level rise disconnected more than three quarters of the >9000 submarine canyons worldwide from their former river or long-shore drift sediment inputs. Existing models therefore assume that land-detached submarine canyons are dormant in the present-day; however, monitoring has focused on land-attached canyons and this paradigm remains untested. Here we present the most detailed field measurements yet of turbidity currents within a land-detached submarine canyon, documenting a remarkably similar frequency (6 yr-1) and speed (up to 5-8 ms-1) to those in large land-attached submarine canyons. Major triggers such as storms or earthquakes are not required; instead, seasonal variations in cross-shelf sediment transport explain temporal-clustering of flows, and why the storm season is surprisingly absent of turbidity currents. As >1000 other canyons have a similar configuration, we propose that contemporary deep-sea particulate transport via such land- detached canyons may have been dramatically under-estimated.
    to
    Sediment, nutrients, organic carbon and pollutants are funnelled down submarine canyons from continental shelves by sediment-laden flows called turbidity currents, which dominate particulate transfer to the deep-sea. Post-glacial sea-level rise disconnected more than three quarters of the >9000 submarine canyons worldwide from their former river or long-shore drift sediment inputs. Existing models therefore assume that land-detached submarine canyons are dormant in the present-day; however, monitoring has focused on land-attached canyons and this paradigm remains untested. Here we present the most detailed field measurements yet of turbidity currents within a land-detached submarine canyon, documenting a remarkably similar frequency (6/year) and speed (up to 5-8 m/s) to those in large land-attached submarine canyons. Major triggers such as storms or earthquakes are not required; instead, seasonal variations in cross-shelf transport explain temporal-clustering of flows, and why the storm season is surprisingly absent of turbidity currents. As >1000 other canyons have a similar configuration, we propose that contemporary deep-sea particulate transport via such land-detached canyons may have been dramatically under-estimated.


  • Changed the source URL of ADCP data Whittard Canyon 64PE453-53 from https://dataportal.nioz.nl/doi/10.33591/nioz/7b.b.7c to https://dataportal.nioz.nl/doi/10.25850/nioz/7b.b.7c


  • Changed the version of ADCP data Whittard Canyon 64PE453-53 to 1 (previously 3)


  • Changed value of field dataset_persistent_id to DOI:10.25850/nioz/7b.b.7c in ADCP data Whittard Canyon 64PE453-53