Koji Ohata
Density stratification controls the bedform phase diagram of saline-gravity currents versus open-channel flows
Ohata, Koji; de Cala, Isabel; Dorrell, Robert M.; Naruse, Hajime; McLelland, Stuart J.; Simmons, Stephen M.; McCaffrey, William D.
Authors
Isabel de Cala
Dr Robert Dorrell R.Dorrell@hull.ac.uk
Reader in Environmental Fluid Dynamics
Hajime Naruse
Dr Stuart McLelland S.J.McLelland@hull.ac.uk
Interim Co-Director of the Energy and Environment Institute
Dr Steve Simmons S.Simmons@hull.ac.uk
Lecturer in Energy and Environment
William D. McCaffrey
Abstract
Sedimentary bedforms such as ripples and dunes are generated both by river flows and sediment-laden gravity currents. Gravity current deposits are usually parameterized using existing bedform phase diagrams which are based on data from laboratory experiments and field observations of open-channel flows. Yet, it is not evident that open-channel flow bedform phase diagrams are applicable to gravity current deposits. Gravity current hydrodynamics are dependent on vertical density variation, that is density stratification, and therefore are fundamentally different from open-channel flows. New experiments to produce gravity current deposits are conducted and compared to existing open-channel flow data. It is shown that a parameter phase-space based on the lower layer of stratified gravity currents (i.e. that part below the velocity maximum) significantly improves the prediction of bedform type compared to bedform phase diagrams derived from layer-averaged parameters. These results confirm that bedforms produced by gravity currents can only be predicted accurately using the characteristics of the lower layer of stratified flow.
Citation
Ohata, K., de Cala, I., Dorrell, R. M., Naruse, H., McLelland, S. J., Simmons, S. M., & McCaffrey, W. D. (in press). Density stratification controls the bedform phase diagram of saline-gravity currents versus open-channel flows. Sedimentology, https://doi.org/10.1111/sed.13075
| Journal Article Type | Article |
|---|---|
| Acceptance Date | Dec 16, 2022 |
| Online Publication Date | Jan 18, 2023 |
| Deposit Date | Feb 2, 2023 |
| Publicly Available Date | Jan 19, 2024 |
| Journal | Sedimentology |
| Print ISSN | 0037-0746 |
| Electronic ISSN | 1365-3091 |
| Publisher | Wiley |
| Peer Reviewed | Peer Reviewed |
| DOI | https://doi.org/10.1111/sed.13075 |
| Keywords | Bedforms; Bedform phase diagram; Density stratification; Gravity currents; Open-channel flows |
| Public URL | https://hull-repository.worktribe.com/output/4189954 |
Files
This file is under embargo until Jan 19, 2024 due to copyright reasons.
Contact S.Simmons@hull.ac.uk to request a copy for personal use.