The University of Southampton
University of Southampton Institutional Repository

Rip current observations on a low-sloping dissipative beach

Rip current observations on a low-sloping dissipative beach
Rip current observations on a low-sloping dissipative beach
Rip currents are the main cause of beach rescues and fatalities. Key drivers of rip current hazard are: (1) fast current speeds; and (2) the exit rate of floating material from inside to outside of the surf zone. Exit rates may vary temporally, such as due to Very Low Frequency (VLF) motions, which have a period on the order of 10 minutes. However, there is little field data to determine the driver(s) of exit rate. Therefore, the aim of this research was to determine rip current circulation patterns, and specifically, determine their relationship to surf zone exits, on a high-energy dissipative beach. Three days of field measurements were undertaken at Ngarunui Beach, New Zealand. Three daily surf zone flow patterns were found: (1) alongshore; (2) surf zone eddy with high exit rate; and (3) surf zone eddy with no exits. There were strong infragravity peaks in energy within the surf zone, at 30-45s, although none at VLF (~10 minute) frequencies. Further research is underway to determine what drove the high surf zone exit rate observed at Ngarunui Beach.
rip currents, video imagery, dissipative beach, surf zone, infragravity waves
Australasian Coasts & Ports Conference
Gallop, Shari L.
be66589c-137a-4e23-81d2-8e3b901a5307
Bryan, Karin R.
85ba8507-148b-46b5-b2bc-c250b663753b
Pitman, Sebastian
7657cca5-521d-4731-801a-efb3d9a9efc2
Ranasinghe, Roshanka
595401f8-1450-454d-b9ec-1ea3de9eebb4
Sandwell, Dean
946af9e4-736f-4624-bd96-949f2252a9a4
Gallop, Shari L.
be66589c-137a-4e23-81d2-8e3b901a5307
Bryan, Karin R.
85ba8507-148b-46b5-b2bc-c250b663753b
Pitman, Sebastian
7657cca5-521d-4731-801a-efb3d9a9efc2
Ranasinghe, Roshanka
595401f8-1450-454d-b9ec-1ea3de9eebb4
Sandwell, Dean
946af9e4-736f-4624-bd96-949f2252a9a4

Gallop, Shari L., Bryan, Karin R., Pitman, Sebastian, Ranasinghe, Roshanka and Sandwell, Dean (2015) Rip current observations on a low-sloping dissipative beach. In Australasian Coasts & Ports Conference 2015. Australasian Coasts & Ports Conference. 4 pp .

Record type: Conference or Workshop Item (Paper)

Abstract

Rip currents are the main cause of beach rescues and fatalities. Key drivers of rip current hazard are: (1) fast current speeds; and (2) the exit rate of floating material from inside to outside of the surf zone. Exit rates may vary temporally, such as due to Very Low Frequency (VLF) motions, which have a period on the order of 10 minutes. However, there is little field data to determine the driver(s) of exit rate. Therefore, the aim of this research was to determine rip current circulation patterns, and specifically, determine their relationship to surf zone exits, on a high-energy dissipative beach. Three days of field measurements were undertaken at Ngarunui Beach, New Zealand. Three daily surf zone flow patterns were found: (1) alongshore; (2) surf zone eddy with high exit rate; and (3) surf zone eddy with no exits. There were strong infragravity peaks in energy within the surf zone, at 30-45s, although none at VLF (~10 minute) frequencies. Further research is underway to determine what drove the high surf zone exit rate observed at Ngarunui Beach.

Text
Gallop_et_al_2015.pdf - Author's Original
Download (258kB)

More information

Published date: 15 September 2015
Venue - Dates: Australasian Coasts & Ports Conference 2015, Auckland, New Zealand, 2015-09-14 - 2015-09-17
Keywords: rip currents, video imagery, dissipative beach, surf zone, infragravity waves
Organisations: Geology & Geophysics, Ocean and Earth Science, Coastal & Shelf Research

Identifiers

Local EPrints ID: 381834
URI: http://eprints.soton.ac.uk/id/eprint/381834
PURE UUID: 364162ee-3475-4524-bde7-62f50a80f0c4

Catalogue record

Date deposited: 23 Sep 2015 09:30
Last modified: 26 Apr 2022 18:01

Export record

Contributors

Author: Shari L. Gallop
Author: Karin R. Bryan
Author: Sebastian Pitman
Author: Roshanka Ranasinghe
Author: Dean Sandwell

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×