Data

Average time between events when the Shields parameter exceeds 0.25

Geoscience Australia
Hughes, M.
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://pid.geoscience.gov.au/dataset/ga/77002&rft.title=Average time between events when the Shields parameter exceeds 0.25&rft.identifier=https://pid.geoscience.gov.au/dataset/ga/77002&rft.publisher=Geoscience Australia&rft.description=This data represents the average time between events when the Shields parameter (Shields, 1936) exceeds 0.25 based on a Peaks-Over-Thresholds (POT) analysis. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches. 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. The unit for the dataset is day. Shields, A. 1936. Application of similarity principles and turbulence research to bed-load movement. Mitteilunger der Preussischen Versuchsanstalt f'ur Wasserbau und Schiffbau 26: 5-24Maintenance and Update Frequency: notPlannedStatement: 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.&rft.creator=Hughes, M. &rft.date=2013&rft.coverage=westlimit=110.0; southlimit=-44.0; eastlimit=156.0; northlimit=-7.0&rft.coverage=westlimit=110.0; southlimit=-44.0; eastlimit=156.0; northlimit=-7.0&rft_rights=&rft_rights=Creative Commons Attribution 4.0 International Licence&rft_rights=CC-BY&rft_rights=4.0&rft_rights=http://creativecommons.org/licenses/&rft_rights=WWW:LINK-1.0-http--link&rft_rights=Australian Government Security ClassificationSystem&rft_rights=https://www.protectivesecurity.gov.au/Pages/default.aspx&rft_rights=WWW:LINK-1.0-http--link&rft_rights=Creative Commons Attribution 4.0 International Licence http://creativecommons.org/licenses/by/4.0&rft_subject=oceans&rft_subject=Marine Data&rft_subject=seabed&rft_subject=oceanography&rft_subject=NERP Marine Biodiversity Hub&rft_subject=marine&rft_subject=NERP&rft_subject=Marine Geoscience&rft_subject=EARTH SCIENCES&rft_subject=GEOLOGY&rft_subject=Published_External&rft.type=dataset&rft.language=English Access the data
Cite Saved to MyRDA Save to MyRDA

Licence & Rights:

Open Licence view details
CC-BY

Creative Commons Attribution 4.0 International Licence
http://creativecommons.org/licenses/by/4.0

Creative Commons Attribution 4.0 International Licence

CC-BY

4.0

http://creativecommons.org/licenses/

WWW:LINK-1.0-http--link

Australian Government Security ClassificationSystem

https://www.protectivesecurity.gov.au/Pages/default.aspx

WWW:LINK-1.0-http--link

Access:

Open

Brief description

This data represents the average time between events when the Shields parameter (Shields, 1936) exceeds 0.25 based on a Peaks-Over-Thresholds (POT) analysis. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches. 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. The unit for the dataset is day. 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

Lineage

Maintenance and Update Frequency: notPlanned
Statement: 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.

Issued: 2013

This dataset is part of a larger collection

Click to explore relationships graph
Help

Related Organisations

Related People

156,-7 156,-44 110,-44 110,-7 156,-7

133,-25.5

text: westlimit=110.0; southlimit=-44.0; eastlimit=156.0; northlimit=-7.0

Subjects
Earth Sciences | Geology | Marine Data | Marine Geoscience | NERP | NERP Marine Biodiversity Hub | Published_External | marine | oceanography | oceans | seabed |

User Contributed Tags    

Login to tag this record with meaningful keywords to make it easier to discover

Other Information
Download the data (ArcGIS-grid) (File download)

uri : https://d28rz98at9flks.cloudfront.net/77002/77002_shield_time.zip

Identifiers
Similar data you may be interested in: