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Small-scale morphology across the surf zone

Marine Geology

By:
, ,
DOI: 10.1016/S0025-3227(97)00114-X

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Abstract

Small-scale (< 5 m horizontal length) nearshore morphologic height variations were measured by combining CRAB surveys with bed elevations acquired with a 1 MHz sonic altimeter mounted on the CRAB during the October Phase of the DUCK94 experiment. Bedform plan views were recorded simultaneously using a 500 kHz side-scan sonar mounted on the CRAB. Waves and currents were measured at the same time. Significant temporal and spatial variations in the small-scale morphology were measured in response to changing waves and currents during the 2 weeks examined. Three cases are examined in detail: (1) mild waves and weak longshore currents resulting in wave ripples throughout the study area; (2) storm waves with strong longshore currents resulting in lunate and straight-crested mega-ripples in the trough of the barred beach; and (3) narrow-band, normally incident waves with a strong rip current resulting in a planar bed except in the throat of the rip where mega-ripples were measured. Wavenumber spectra of the bed were generally broad, indicating newly formed ripples coexisted with residual ripples from the past to form complex, multi-scaled ripple patterns.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Small-scale morphology across the surf zone
Series title:
Marine Geology
DOI:
10.1016/S0025-3227(97)00114-X
Volume
145
Issue:
3-4
Year Published:
1998
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Marine Geology
First page:
173
Last page:
196
Number of Pages:
24