Wave‐driven setup and alongshore flows observed onshore of a submarine canyon

Apotsos, Alex; Raubenheimer, Britt; Elgar, Steve; Guza, R. T.

doi:10.1029/2007jc004514

Cited by 48 publications

(67 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar to previous results [van der Westhuysen, 2010;Gorrell et al, 2011;and many others], the model skillfully predicts the wave heights observed in 7 ( Model simulations suggest strong spatial inhomogeneity in wave heights ( Figure 6a) and directions ( Figure 6b) onshore of the complex bathymetry, similar to nearshore waves in other locations [Apotsos et al, 2008;Chen et al, 2015;and others] suggest that the size and location of the region of flow separation are sensitive to bathymetry and shoreline shape, which may not be accurate near the separation region. Model skill is higher a few km to the west (e.g., x=3.3 km, Figure 8b), away from the separation region.…”

Section: A Model-data Comparisonssupporting

confidence: 70%

“…Breaking waves dissipate energy while transferring momentum flux to the water column. In the surf zone, the time-averaged wave-driven forcing raises water levels near the shoreline [Longuet-Higgins and Stewart, 1964], producing alongshore varying sea levels and currents [Apotsos et al, 2008;Shi et al, 2011; and, in the case of obliquely incident waves, driving alongshore currents in the direction of wave propagation [Longuet-Higgins, 1970;Thornton and Guza, 1986;Guza et al, 1986;Feddersen et al, 1998;and many others]. The wave-orbital velocities and wave-generated mean currents can transport sediment and act as a mechanism for shoreline evolution references therein; and many others].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Field observations and numerical model simulations of a migrating inlet system

Hopkins¹

2017

View full text Add to dashboard Cite

Waves, currents, and bathymetric change observed along 11 km of the southern shoreline of Martha's Vineyard include storm events, strong tidal flows (> 2 m/s), and an inlet migrating 2.5 km in ~7 years. A field-verified Delft3D numerical model developed for this system is used to examine the hydrodynamics in the nearshore and their effect on the migrating inlet. An initial numerical experiment showed that the observed 70⁰ tidal modulation of wave direction in the nearshore was owing to interactions with tidal currents, and not to depth-induced refraction as waves propagated over complex shallow bathymetry. A second set of simulations focused on the separation of tidal currents from the southeast corner of Martha's Vineyard, showing the positive correlation between flow separation and sediment transport around a curved shoreline. Observations of waves, currents, and bathymetric change during hurricanes were reproduced in a third numerical experiment examining the competition between storm waves, which enhance inlet migration, and strong tidal currents, which scour the inlet and reduce migration rates. The combined field observations and simulations examined here demonstrate the importance of wave and tidal current forcings on morphological evolution at timescales of days to months.

show abstract

Section: A Model-data Comparisonssupporting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Field observations and numerical model simulations of a migrating inlet system

Hopkins¹

2017

View full text Add to dashboard Cite

show abstract

“…6). Waves that approach the coast obliquely mostly produce longshore current rather than high set-up because the cross-shore component of the radiation stress is mostly responsible for set-up (Apotsos et al, 2008). The highest set-up occurs when waves approach the coast almost perpendicularly (i.e.…”

Section: Almost-incident Wavesmentioning

confidence: 99%

Mapping wave set-up near a complex geometric urban coastline

Soomere

Pindsoo

Bishop

et al. 2013

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Wave induced set-up is a process that leads to increased water levels in coastal regions. When coupled with storm conditions, wave set-up -or, for brevity, set-up -can significantly increase the risk of flooding or structural damage and therefore is of particular importance when considering coastal management or issues related to the planning of nearshore infrastructures. Here, we investigate the effects of set-up in the coastal region of the Gulf of Finland in the Baltic Sea, close to Tallinn, Estonia, although the results will have wider relevance for many other areas. Due to a lack of continuous wave data we employ modelling to provide input data using a calculation scheme based on a high-resolution (470 m) spectral wave model WAM to replicate spatial patterns of wave properties based on high-quality, instrumentmeasured wind data from the neighbourhood of the study site. The results indicate that for the specific geometry of coastline under consideration, there is a variation in set-up which is strongly affected by wind direction. The maximum set-up values are up to 70-80 cm in selected locations. This is more than 50 % of the all-time maximum water level and thus may serve as a substantial source of marine hazard for several low-lying regions around the city. Wind directions during storms have changed in recent years and, with climate variability potentially increasing, these results will encourage further tests which may be used in a policy setting regarding defences or other structures in and around coastlines. In particular, with urban development now taking place in many coastal regions (including the one within this study) these results have implications for local planners. They may also be incorporated into new storm warning systems.

show abstract

“…Tidal elevation, channel depth, significant wave height, energy-weighted wave direction, and period corresponding to the centroid of the sea-surface elevation spectrum for 4 dates. threshold for breaking [Thornton and Guza, 1983;Raubenheimer et al, 1996;Apotsos et al, 2008a], but not in the deeper channel (Figure 4.6C). When waves break, their momentum flux is transferred to the water column, driving an increasing water level or setup [Longuet-Higgins and Stewart, 1964;Lentz and Raubenheimer, 1999;Raubenheimer et al, 2001, and many others] (Figure 4.6D, dashed contours).…”

Section: Flow Patternsmentioning

confidence: 99%

“…When incident waves propagate over alongshore-variable bathymetry, spatial variations in breaking-wave-driven setup lead to non-uniformities in the alongshore flow and offshore-directed flows near bathymetric depressions [Sonu, 1972;Oltman-Shay et al, 1989;Svendsen and Putrevu, 1990;Putrevu et al, 1995;Sancho, 1998;Slinn et al, 2000;Apotsos et al, 2008a, Hansen et al, 2015.…”

Section: Introductionmentioning

confidence: 99%

Hydrodynamic and morphodynamic responses to surfzone seafloor perturbations

Moulton¹

2016

View full text Add to dashboard Cite

Holes and channels were excavated in the surf zone on an ocean beach near Duck, NC, and observations of the subsequent evolution of waves, currents, and the modified seafloor were used to investigate nearshore dynamics. In one set of seafloor perturbation experiments, deep holes with steeply sloping sides were excavated in the inner surfzone seafloor. Observations of the infilling holes were used to make the first field estimates of the surfzone morphological diffusivity, which describes the rate of seafloor smoothing by downslope sediment transport. To improve the temporal resolution of bathymetric estimates, a mapping method was developed to combine infrequent, spatially dense watercraft surveys with continuous, spatially sparse in situ altimeter estimates of the seafloor location. In another set of seafloor perturbation experiments, channels were dredged across the surf zone with the propellers of a landing craft. Alongshore variations in wave breaking caused by the perturbed bathymetry resulted in strong rip currents in the channels under some conditions, whereas alongshore currents bypassed the channels under other conditions. The dynamics of the circulation response for changing wave forcing, bathymetry, and tidal elevation are investigated using the observations, a numerical model, and a parameter based on wave properties and bathymetry.

show abstract

Wave‐driven setup and alongshore flows observed onshore of a submarine canyon

Cited by 48 publications

References 38 publications

Field observations and numerical model simulations of a migrating inlet system

Field observations and numerical model simulations of a migrating inlet system

Mapping wave set-up near a complex geometric urban coastline

Hydrodynamic and morphodynamic responses to surfzone seafloor perturbations

Contact Info

Product

Resources

About