Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska
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...
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Online Access: | http://dx.doi.org/10.22541/essoar.169323663.36581869/v1 |
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crwinnower:10.22541/essoar.169323663.36581869/v1 2024-06-02T08:02:33+00:00 Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska Eidam, Emily Thomson, Jim Malito, John Hosekova, Lucia 2023 http://dx.doi.org/10.22541/essoar.169323663.36581869/v1 unknown Authorea, Inc. posted-content 2023 crwinnower https://doi.org/10.22541/essoar.169323663.36581869/v1 2024-05-07T14:19:23Z 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 (1) longer open-water seasons when waves can contribute to sediment transport, and (2) 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. Other/Unknown Material Arctic Chukchi Chukchi Sea Sea ice Alaska The Winnower Arctic Chukchi Sea The Shoals ENVELOPE(-56.498,-56.498,49.817,49.817) |
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description |
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 (1) longer open-water seasons when waves can contribute to sediment transport, and (2) 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. |
format |
Other/Unknown Material |
author |
Eidam, Emily Thomson, Jim Malito, John Hosekova, Lucia |
spellingShingle |
Eidam, Emily Thomson, Jim Malito, John Hosekova, Lucia Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska |
author_facet |
Eidam, Emily Thomson, Jim Malito, John Hosekova, Lucia |
author_sort |
Eidam, Emily |
title |
Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska |
title_short |
Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska |
title_full |
Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska |
title_fullStr |
Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska |
title_full_unstemmed |
Morphology and sediment dynamics of Blossom Shoals at Icy Cape, Alaska |
title_sort |
morphology and sediment dynamics of blossom shoals at icy cape, alaska |
publisher |
Authorea, Inc. |
publishDate |
2023 |
url |
http://dx.doi.org/10.22541/essoar.169323663.36581869/v1 |
long_lat |
ENVELOPE(-56.498,-56.498,49.817,49.817) |
geographic |
Arctic Chukchi Sea The Shoals |
geographic_facet |
Arctic Chukchi Sea The Shoals |
genre |
Arctic Chukchi Chukchi Sea Sea ice Alaska |
genre_facet |
Arctic Chukchi Chukchi Sea Sea ice Alaska |
op_doi |
https://doi.org/10.22541/essoar.169323663.36581869/v1 |
_version_ |
1800747034509049856 |