Percentage of time the Shields parameter exceeds 0.25  


Authors / CoAuthors

Hughes, M.

Abstract

This data represents the percentage of time the Shields parameter (Shields, 1936) exceeds 0.25. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches on the seabed. This value is several times larger than that required to initiate traction bedload transport (~0.05) and falls in the middle of the ripple and dune bedform stability field. It represents conditions when the seabed is highly mobile and where patches of disturbed habitat are likely to be created. Shields, A. 1936. Application of similarity principles and turbulence research to bed-load movement. Mitteilunger der Preussischen Versuchsanstalt f¨ur Wasserbau und Schiffbau 26: 5-24

Product Type

dataset

eCat Id

77000

Contact for the resource

  Custodian

EGD  

  Owner

Commonwealth of Australia (Geoscience Australia)  

  Custodian

Commonwealth of Australia (Geoscience Australia)  
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

Keywords

  • Marine Data
( Theme )
  • seabed
( Theme )
  • oceanography
( Theme )
  • NERP Marine Biodiversity Hub
( Theme )
  • marine
( Theme )
  • NERP
Australian and New Zealand Standard Research Classification (ANZSRC)
  • Marine Geoscience
  • Published_External

Publication Date

2013-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

Status

Purpose

Maintenance Information

notPlanned

Topic Category

oceans

Series Information

Lineage

Geoscience Australia's GEOMACS (Geological and Oceanographic Model of Australia's Continental Shelf) model was utilised to produce hindcast hourly time series of continental shelf (~20 - 300 m depth) bed shear stress on a 0.1 degree grid covering the period March 1997 to February 2008 (inclusive). The hindcast data represents the combined contribution to the bed shear stress by waves, tides, wind and density-driven circulation. The Shields parameter was obtained from the GEOMACS model. Please refer to Hughes et al. (2010) for further details. Hughes, M.G., Harris, P.T., Brooke, B.P., 2010. Seabed exposure and ecological disturbance on Australia's continental shelf: Potential surrogates for marine biodiversity. Geoscience Australia Record 2010/43, 77pp.

Parent Information

Extents

[-44.0, -7.0, 110.0, 156.0]

Reference System

Spatial Resolution

Service Information

Associations

Downloads and Links

File download  

Source Information

NERP Marine Biodiversity Hub