Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan
Recent gravity flows on the Bear Island Fan consist of fine-grained sediments that presently exhibit high densities (1.8–2.0 g/cm3), low water contents (30–40% dry weight), and high (estimated) yield strengths (1100–1350 Pa). Rheological analyses, however, reveal exceptionally low yield strengths (3...
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ftsouthmissispun:oai:aquila.usm.edu:fac_pubs-4244 2023-07-30T04:02:35+02:00 Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan Bowles, Frederick A. Faas, Richard W. Vogt, Peter R. Sawyer, William B. Stephens, Kevin 2003-06-15T07:00:00Z https://aquila.usm.edu/fac_pubs/3245 https://doi-org.lynx.lib.usm.edu/10.1016/S0025-3227(03)00089-6 unknown The Aquila Digital Community https://aquila.usm.edu/fac_pubs/3245 https://doi-org.lynx.lib.usm.edu/10.1016/S0025-3227(03)00089-6 Faculty Publications Barents Sea Bear Island Fan mudflows sediment properties rheology Earth Sciences Geology Physical Sciences and Mathematics text 2003 ftsouthmissispun 2023-07-15T18:43:44Z Recent gravity flows on the Bear Island Fan consist of fine-grained sediments that presently exhibit high densities (1.8–2.0 g/cm3), low water contents (30–40% dry weight), and high (estimated) yield strengths (1100–1350 Pa). Rheological analyses, however, reveal exceptionally low yield strengths (3.5 Pa and lower) for laboratory slurries (3) made with the mudflow sediments. The low yield strengths are inconsistent with previous interpretations that the mudflows were spawned from glacial sediments that were rapidly deposited as till deltas on the upper slope of the fan, or that they were emplaced as low-density, low-cohesion, fluidized mud. Abundant glacial flour in the mudflow samples is indicative of subglacial meltwater discharge. This, in turn, suggests that the sediment originated from turbid plumes that settled into a low-density, high-water-content mud deposit in an open-marine, tidewater glacier environment. Such an environment may have existed during the mid/late Weichselian when an embayment in the Barents shelf ice-sheet left much of the inner shelf ice-free. Subsequent advance of the ice front closed the embayment, compressing the mud. Loss of water during compression increased the bulk density and yield strength of the mud. The modified embayment mud was gradually pushed off the shelf, generating mudflows on the fan. Morphologic evidence suggests that some mudflows may have hydroplaned, indicating that flow speeds varied above and below a critical speed (ca. 5 m/s) marking the onset of hydroplaning. Text Barents Sea Bear Island Ice Sheet Tidewater The University of Southern Mississippi: The Aquila Digital Community Barents Sea Bear Island ENVELOPE(-67.250,-67.250,-68.151,-68.151) Marine Geology 197 1-4 63 74 |
institution |
Open Polar |
collection |
The University of Southern Mississippi: The Aquila Digital Community |
op_collection_id |
ftsouthmissispun |
language |
unknown |
topic |
Barents Sea Bear Island Fan mudflows sediment properties rheology Earth Sciences Geology Physical Sciences and Mathematics |
spellingShingle |
Barents Sea Bear Island Fan mudflows sediment properties rheology Earth Sciences Geology Physical Sciences and Mathematics Bowles, Frederick A. Faas, Richard W. Vogt, Peter R. Sawyer, William B. Stephens, Kevin Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan |
topic_facet |
Barents Sea Bear Island Fan mudflows sediment properties rheology Earth Sciences Geology Physical Sciences and Mathematics |
description |
Recent gravity flows on the Bear Island Fan consist of fine-grained sediments that presently exhibit high densities (1.8–2.0 g/cm3), low water contents (30–40% dry weight), and high (estimated) yield strengths (1100–1350 Pa). Rheological analyses, however, reveal exceptionally low yield strengths (3.5 Pa and lower) for laboratory slurries (3) made with the mudflow sediments. The low yield strengths are inconsistent with previous interpretations that the mudflows were spawned from glacial sediments that were rapidly deposited as till deltas on the upper slope of the fan, or that they were emplaced as low-density, low-cohesion, fluidized mud. Abundant glacial flour in the mudflow samples is indicative of subglacial meltwater discharge. This, in turn, suggests that the sediment originated from turbid plumes that settled into a low-density, high-water-content mud deposit in an open-marine, tidewater glacier environment. Such an environment may have existed during the mid/late Weichselian when an embayment in the Barents shelf ice-sheet left much of the inner shelf ice-free. Subsequent advance of the ice front closed the embayment, compressing the mud. Loss of water during compression increased the bulk density and yield strength of the mud. The modified embayment mud was gradually pushed off the shelf, generating mudflows on the fan. Morphologic evidence suggests that some mudflows may have hydroplaned, indicating that flow speeds varied above and below a critical speed (ca. 5 m/s) marking the onset of hydroplaning. |
format |
Text |
author |
Bowles, Frederick A. Faas, Richard W. Vogt, Peter R. Sawyer, William B. Stephens, Kevin |
author_facet |
Bowles, Frederick A. Faas, Richard W. Vogt, Peter R. Sawyer, William B. Stephens, Kevin |
author_sort |
Bowles, Frederick A. |
title |
Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan |
title_short |
Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan |
title_full |
Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan |
title_fullStr |
Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan |
title_full_unstemmed |
Sediment Properties, Flow Characteristics, and Depositional Environment of Submarine Mudflows, Bear Island Fan |
title_sort |
sediment properties, flow characteristics, and depositional environment of submarine mudflows, bear island fan |
publisher |
The Aquila Digital Community |
publishDate |
2003 |
url |
https://aquila.usm.edu/fac_pubs/3245 https://doi-org.lynx.lib.usm.edu/10.1016/S0025-3227(03)00089-6 |
long_lat |
ENVELOPE(-67.250,-67.250,-68.151,-68.151) |
geographic |
Barents Sea Bear Island |
geographic_facet |
Barents Sea Bear Island |
genre |
Barents Sea Bear Island Ice Sheet Tidewater |
genre_facet |
Barents Sea Bear Island Ice Sheet Tidewater |
op_source |
Faculty Publications |
op_relation |
https://aquila.usm.edu/fac_pubs/3245 https://doi-org.lynx.lib.usm.edu/10.1016/S0025-3227(03)00089-6 |
container_title |
Marine Geology |
container_volume |
197 |
container_issue |
1-4 |
container_start_page |
63 |
op_container_end_page |
74 |
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1772813398430449664 |