Extreme low-frequency waves on the Ofu, American Samoa, reef flat

Olivia M. Cheriton; Curt D. Storlazzi; Ferdinand K.J. Oberle; Kurt J. Rosenberger; Eric K. Brown

doi:10.1007/s00338-023-02453-w

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USGS · 70251134

Extreme low-frequency waves on the Ofu, American Samoa, reef flat

Olivia M. Cheriton·Curt D. Storlazzi·Ferdinand K.J. Oberle·Kurt J. Rosenberger·Eric K. Brown

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Abstract

The southern fringing reef along Ofu, American Samoa, has been a focus of coral research owing to the presence of super-heated pools on the reef flat, where corals thrive in elevated sea temperatures. Here, we present the first documentation of exceptionally large low-frequency (periods > 100 s) waves over this reef flat. During a large, southerly swell event, low-frequency waves on the inner reef flat had mean heights of 0.7 m and periods of 2–4 min and are estimated to have contributed up to 50% of the total water levels. One observed low-frequency wave had a trough-to-peak vertical height of 1.5 m, possibly representing the largest low-frequency wave ever directly observed on a reef flat. These large, low-frequency waves, which were likely amplified by reef resonance, are important factors in coastal hazards such as flooding and erosion and may also be relevant to coral health and resilience.

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Coral Reefs Article

Source-reported bounding extent: -14.198592348996542° to -14.148328735865661° latitude; -169.69863254706598° to -169.61898166815973° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Olivia M. Cheriton, Curt D. Storlazzi, Ferdinand K.J. Oberle, Kurt J. Rosenberger, Eric K. Brown. 2024-01-22. Extreme low-frequency waves on the Ofu, American Samoa, reef flat. https://doi.org/10.1007/s00338-023-02453-w

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