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Abstract Capes and cape‐associated shoals represent sites of convergent sediment transport, and can provide points of relative coastal stability, navigation hazards, and offshore sand resources. Shoal evolution is commonly impacted by the regional wave climate. In the Arctic, changing sea‐ice conditions are leading to (a) longer open‐water seasons when waves can contribute to sediment transport, and (b) an intensified wave climate (related to duration of open water and expanding fetch). At Blossom Shoals offshore of Icy Cape in the Chukchi Sea, these changes have led to a five‐fold increase in the amount of time that sand is mobile at a 31‐m water depth site between the period 1953–1989 and the period 1990–2022. Wave conditions conducive to sand transport are still limited to less than 2% of the year, however—and thus it is not surprising that the overall morphology of the shoals has changed little in 70 years, despite evidence of active sand transport in the form of 1‐m‐scale sand waves on the flanks of the shoals which heal ice keel scours formed during the winter. Suspended‐sediment transport is relatively weak due to limited sources of mud nearby, but can be observed in a net northeastward direction during the winter (driven by the Alaska Coastal Current under the ice) and in a southwestward direction during open‐water wind events. Longer open‐water seasons mean that annual net northeastward transport of fine sediment may weaken, with implications for the residence time of fine‐grained sediments and particle‐associated nutrients in the Chukchi Sea. 

Seafloor moorings measuring pressure and temperature were deployed from April to September 2023 at three sites near the route of the fiber optic telecommunications cable that extends offshore of Oliktok Point, Alaska. The raw data data (1 Hertz (Hz) sampling) are processed for hourly estimates of the ocean surface wave conditions, along with average seawater temperature and average depth. The sites were ice-covered from April to July, then mostly open water in August and September. The data were collected to calibrate proxy wave measurements using Distributed Acoustic Sensing (DAS) from the telecommunications cable. 

This dataset contains processed ocean surface gravity wave parameters derived from interrogation of a seafloor fiber with distributed acoustic sensing (DAS). These measurements were taken on a fiber within a cable owned by Quintillion extending off the coast near Oliktok Point, Alaska in November 2021 and August 2022. Processing includes calculation of frequency-dependent, channel-specific correction factors using collocated wave buoy (SWIFT) observations, which is then multiplied by the PSD of raw strain-rate. A depth-attenuation correction is then also applied. Dataset includes the raw strain-rate spectra and the derived wave spectra, as well as bulk wave parameters including significant wave height (Hs), peak wave period (Tp), and energy-weighted wave period (Te).