Eddy-driven sediment transport in the Argentine Basin: Is the height of the Zapiola Rise hydrodynamically controlled?
In this study, we address the question whether eddy-driven transports in the Argentine Basin can be held responsible for enhanced sediment accumulation over the Zapiola Rise, hence accounting for the existence and growth of this sediment drift. To address this question, we perform a 6 year simulation with a strongly eddying ocean model. We release two passive tracers, with settling velocities that are consistent with silt and clay size particles. Our experiments show contrasting behavior between the silt fraction and the lighter clay. Due to its larger settling velocity, the silt fraction reaches a quasisteady state within a few years, with abyssal sedimentation rates that match net input. In contrast, clay settles only slowly, and its distribution is heavily stratified, being transported mainly along isopycnals. Yet, both size classes display a significant and persistent concentration minimum over the Zapiola Rise. We show that the Zapiola Anticyclone, a strong eddy-driven vortex that circulates around the Zapiola Rise, is a barrier to sediment transport, and hence prevents significant accumulation of sediments on the Rise. We conclude that sediment transport by the turbulent circulation in the Argentine Basin alone cannot account for the preferred sediment accumulation over the Rise. We speculate that resuspensionmore »
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computational and Statistical Sciences Division.
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division.
- University of Oxford, Oxford (United Kingdom). Department of Earth Sciences.
- Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Department of Physical Oceanography.
- Royal Netherlands Institute for Sea Research, den Burg (Netherlands). Department of Physical Oceanography.
- Publication Date:
- Report Number(s):
Journal ID: ISSN 2169-9275
- Grant/Contract Number:
- Published Article
- Journal Name:
- Journal of Geophysical Research. Oceans
- Additional Journal Information:
- Journal Volume: 120; Journal Issue: 3; Journal ID: ISSN 2169-9275
- American Geophysical Union
- Research Org:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Org:
- USDOE National Nuclear Security Administration (NNSA)
- Country of Publication:
- United States
- 58 GEOSCIENCES
- OSTI Identifier:
- Alternate Identifier(s):
- OSTI ID: 1212459; OSTI ID: 1240386; OSTI ID: 1295961