Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast
Two prominent arctic coastal erosion mechanisms affect the coastal bluffs along the North Slope of Alaska. These include the niche erosion/block collapse mechanism and the bluff face thaw/slump mechanism. The niche erosion/block collapse erosion mechanism is dominant where there are few coarse sedim...
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ftdoajarticles:oai:doaj.org/article:491333adb30d446e895c24584cb086af 2023-05-15T15:00:31+02:00 Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast Thomas M. Ravens Sasha Peterson 2021-10-01T00:00:00Z https://doi.org/10.3389/feart.2021.693824 https://doaj.org/article/491333adb30d446e895c24584cb086af EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/feart.2021.693824/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2021.693824 https://doaj.org/article/491333adb30d446e895c24584cb086af Frontiers in Earth Science, Vol 9 (2021) arctic coastal erosion mechanism coarse sediment areal density Science Q article 2021 ftdoajarticles https://doi.org/10.3389/feart.2021.693824 2022-12-31T14:50:54Z Two prominent arctic coastal erosion mechanisms affect the coastal bluffs along the North Slope of Alaska. These include the niche erosion/block collapse mechanism and the bluff face thaw/slump mechanism. The niche erosion/block collapse erosion mechanism is dominant where there are few coarse sediments in the coastal bluffs, the elevation of the beach below the bluff is low, and there is frequent contact between the sea and the base of the bluff. In contrast, the bluff face thaw/slump mechanism is dominant where significant amounts of coarse sediment are present, the elevation of the beach is high, and contact between the sea and the bluff is infrequent. We show that a single geologic parameter, coarse sediment areal density, is predictive of the dominant erosion mechanism and is somewhat predictive of coastal erosion rates. The coarse sediment areal density is the dry mass (g) of coarse sediment (sand and gravel) per horizontal area (cm2) in the coastal bluff. It accounts for bluff height and the density of coarse material in the bluff. When the areal density exceeds 120 g cm−2, the bluff face thaw/slump mechanism is dominant. When the areal density is below 80 g cm−2, niche erosion/block collapse is dominant. Coarse sediment areal density also controls the coastal erosion rate to some extent. For the sites studied and using erosion rates for the 1980–2000 period, when the sediment areal density exceeds 120 g cm−2, the average erosion rate is low or 0.34 ± 0.92 m/yr. For sediment areal density values less than 80 g cm−2, the average erosion rate is higher or 2.1 ± 1.5 m/yr. Article in Journal/Newspaper Arctic north slope Alaska Directory of Open Access Journals: DOAJ Articles Arctic The Bluff ENVELOPE(-61.567,-61.567,-64.367,-64.367) Frontiers in Earth Science 9 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
arctic coastal erosion mechanism coarse sediment areal density Science Q |
spellingShingle |
arctic coastal erosion mechanism coarse sediment areal density Science Q Thomas M. Ravens Sasha Peterson Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast |
topic_facet |
arctic coastal erosion mechanism coarse sediment areal density Science Q |
description |
Two prominent arctic coastal erosion mechanisms affect the coastal bluffs along the North Slope of Alaska. These include the niche erosion/block collapse mechanism and the bluff face thaw/slump mechanism. The niche erosion/block collapse erosion mechanism is dominant where there are few coarse sediments in the coastal bluffs, the elevation of the beach below the bluff is low, and there is frequent contact between the sea and the base of the bluff. In contrast, the bluff face thaw/slump mechanism is dominant where significant amounts of coarse sediment are present, the elevation of the beach is high, and contact between the sea and the bluff is infrequent. We show that a single geologic parameter, coarse sediment areal density, is predictive of the dominant erosion mechanism and is somewhat predictive of coastal erosion rates. The coarse sediment areal density is the dry mass (g) of coarse sediment (sand and gravel) per horizontal area (cm2) in the coastal bluff. It accounts for bluff height and the density of coarse material in the bluff. When the areal density exceeds 120 g cm−2, the bluff face thaw/slump mechanism is dominant. When the areal density is below 80 g cm−2, niche erosion/block collapse is dominant. Coarse sediment areal density also controls the coastal erosion rate to some extent. For the sites studied and using erosion rates for the 1980–2000 period, when the sediment areal density exceeds 120 g cm−2, the average erosion rate is low or 0.34 ± 0.92 m/yr. For sediment areal density values less than 80 g cm−2, the average erosion rate is higher or 2.1 ± 1.5 m/yr. |
format |
Article in Journal/Newspaper |
author |
Thomas M. Ravens Sasha Peterson |
author_facet |
Thomas M. Ravens Sasha Peterson |
author_sort |
Thomas M. Ravens |
title |
Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast |
title_short |
Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast |
title_full |
Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast |
title_fullStr |
Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast |
title_full_unstemmed |
Geologic Controls on Erosion Mechanism on the Alaska Beaufort Coast |
title_sort |
geologic controls on erosion mechanism on the alaska beaufort coast |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/feart.2021.693824 https://doaj.org/article/491333adb30d446e895c24584cb086af |
long_lat |
ENVELOPE(-61.567,-61.567,-64.367,-64.367) |
geographic |
Arctic The Bluff |
geographic_facet |
Arctic The Bluff |
genre |
Arctic north slope Alaska |
genre_facet |
Arctic north slope Alaska |
op_source |
Frontiers in Earth Science, Vol 9 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/feart.2021.693824/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2021.693824 https://doaj.org/article/491333adb30d446e895c24584cb086af |
op_doi |
https://doi.org/10.3389/feart.2021.693824 |
container_title |
Frontiers in Earth Science |
container_volume |
9 |
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1766332613014847488 |