Open AccessWave setup over a Pacific Island fringing reef
Author(s) -
Vetter O.,
Becker J. M.,
Merrifield M. A.,
Pequignet A.C.,
Aucan J.,
Boc S. J.,
Pollock C. E.
Publication year - 2010
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jc006455
Subject(s) - reef , wave setup , fringing reef , geology , shore , breaking wave , storm , wave height , wind wave , significant wave height , sea state , surf zone , momentum (technical analysis) , oceanography , wave propagation , physics , mechanical wave , longitudinal wave , finance , quantum mechanics , economics
Measurements obtained across a shore‐attached, fringing reef on the southeast coast of the island of Guam are examined to determine the relationship between incident waves and wave‐driven setup during storm and nonstorm conditions. Wave setup on the reef flat correlates well ( r > 0.95) and scales near the shore as approximately 35% of the incident root mean square wave height in 8 m water depth. Waves generated by tropical storm Man‐Yi result in a 1.3 m setup during the peak of the storm. Predictions based on traditional setup theory (steady state, inviscid cross‐shore momentum and depth‐limited wave breaking) and an idealized model of localized wave breaking at the fore reef are in agreement with the observations. The reef flat setup is used to estimate a similarity parameter at breaking that is in agreement with observations from a steeply sloping sandy beach. A weak (∼10%) increase in setup is observed across the reef flat during wave events. The inclusion of bottom stress in the cross‐shore momentum balance may account for a portion of this signal, but this assessment is inconclusive as the reef flat currents in some cases are in the wrong direction to account for the increase. An independent check of fringing reef setup dynamics is carried out for measurements at the neighboring island of Saipan with good agreement.