Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica
Large volumes of aeolian sand and dust are deflated from unconsolidated till deposits, and supraglacial debris surrounding McMurdo Sound, Antarctica. This material is transported offshore with windblown snow onto extensive winter-formed sea ice in the southwest Ross Sea, and is subsequently released...
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Victoria University of Wellington
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ftvuwellington:oai:researcharchive.vuw.ac.nz:10063/3067 2023-08-15T12:37:33+02:00 Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica Chewings, Jane Margaret Atkins, Cliff Dunbar, Gavin Golledge, Nicholas 2013 http://researcharchive.vuw.ac.nz/handle/10063/3067 en_NZ eng Victoria University of Wellington http://researcharchive.vuw.ac.nz/handle/10063/3067 Aeolian Sedimentation Antarctica Text Master's 2013 ftvuwellington 2023-07-25T17:24:00Z Large volumes of aeolian sand and dust are deflated from unconsolidated till deposits, and supraglacial debris surrounding McMurdo Sound, Antarctica. This material is transported offshore with windblown snow onto extensive winter-formed sea ice in the southwest Ross Sea, and is subsequently released into the water-column during summer sea ice breakup. Aeolian sediment samples were collected from a ~600 km² area of sea ice in western McMurdo Sound to determine the magnitude of deposition and identify sediment sources. A new 2-dimensional numerical aeolian sediment transport model (NaMASTE) tuned specifically for the McMurdo Sound area, was used to explore the ability of the local wind system to move sediment from source areas to sea ice and to determine the pattern and extent of aeolian sediment dispersal to the southwest Ross Sea. Debris deposits on the McMurdo Ice Shelf debris bands are the most dominant sediment source for the area. Unconsolidated deposits between Cape Bernacchi and Spike Cape, and the Taylor Valley mouth are significant secondary deposits. Mass accumulation rates varied between 0.15 g m⁻² y⁻¹ and 54.6 g m⁻² y⁻¹, equating to a background aeolian sediment accumulation rate, excluding extremely high values, of 1.14 ± 0.59 g m⁻² y⁻¹ for the McMurdo Sound coastal sea ice zone. This is 3–5 orders of magnitude more than global background dust fallout for the Ross Sea. Modal grain size is very-fine sand to coarse silt. Notably, much of this material is distributed in localised, high sand content plumes that are oriented downwind from source, with finer deposits found outside these zones. An average seafloor linear sedimentation rate of 0.2 cm ky⁻¹ is calculated for McMurdo Sound, which is minor compared to biogenic sedimentation for the region. This equates to ~0.7 Gg y⁻¹ aeolian sediment entering McMurdo Sound during sea ice melt. Application of NaMASTE successfully simulated the general aeolian sediment distribution pattern. Testing of model variables suggests that aeolian material is mainly ... Master Thesis Antarc* Antarctica Ice Shelf McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice Victoria University of Wellington: ResearchArchive Bernacchi ENVELOPE(163.850,163.850,-77.483,-77.483) Cape Bernacchi ENVELOPE(163.450,163.450,-77.467,-77.467) McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) McMurdo Sound Ross Sea Spike Cape ENVELOPE(163.567,163.567,-77.300,-77.300) Taylor Valley ENVELOPE(163.000,163.000,-77.617,-77.617) |
institution |
Open Polar |
collection |
Victoria University of Wellington: ResearchArchive |
op_collection_id |
ftvuwellington |
language |
English |
topic |
Aeolian Sedimentation Antarctica |
spellingShingle |
Aeolian Sedimentation Antarctica Chewings, Jane Margaret Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica |
topic_facet |
Aeolian Sedimentation Antarctica |
description |
Large volumes of aeolian sand and dust are deflated from unconsolidated till deposits, and supraglacial debris surrounding McMurdo Sound, Antarctica. This material is transported offshore with windblown snow onto extensive winter-formed sea ice in the southwest Ross Sea, and is subsequently released into the water-column during summer sea ice breakup. Aeolian sediment samples were collected from a ~600 km² area of sea ice in western McMurdo Sound to determine the magnitude of deposition and identify sediment sources. A new 2-dimensional numerical aeolian sediment transport model (NaMASTE) tuned specifically for the McMurdo Sound area, was used to explore the ability of the local wind system to move sediment from source areas to sea ice and to determine the pattern and extent of aeolian sediment dispersal to the southwest Ross Sea. Debris deposits on the McMurdo Ice Shelf debris bands are the most dominant sediment source for the area. Unconsolidated deposits between Cape Bernacchi and Spike Cape, and the Taylor Valley mouth are significant secondary deposits. Mass accumulation rates varied between 0.15 g m⁻² y⁻¹ and 54.6 g m⁻² y⁻¹, equating to a background aeolian sediment accumulation rate, excluding extremely high values, of 1.14 ± 0.59 g m⁻² y⁻¹ for the McMurdo Sound coastal sea ice zone. This is 3–5 orders of magnitude more than global background dust fallout for the Ross Sea. Modal grain size is very-fine sand to coarse silt. Notably, much of this material is distributed in localised, high sand content plumes that are oriented downwind from source, with finer deposits found outside these zones. An average seafloor linear sedimentation rate of 0.2 cm ky⁻¹ is calculated for McMurdo Sound, which is minor compared to biogenic sedimentation for the region. This equates to ~0.7 Gg y⁻¹ aeolian sediment entering McMurdo Sound during sea ice melt. Application of NaMASTE successfully simulated the general aeolian sediment distribution pattern. Testing of model variables suggests that aeolian material is mainly ... |
author2 |
Atkins, Cliff Dunbar, Gavin Golledge, Nicholas |
format |
Master Thesis |
author |
Chewings, Jane Margaret |
author_facet |
Chewings, Jane Margaret |
author_sort |
Chewings, Jane Margaret |
title |
Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica |
title_short |
Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica |
title_full |
Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica |
title_fullStr |
Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica |
title_full_unstemmed |
Sedimentology and numerical modelling of aeolian sediment dispersal, McMurdo Sound, southwest Ross Sea, Antarctica |
title_sort |
sedimentology and numerical modelling of aeolian sediment dispersal, mcmurdo sound, southwest ross sea, antarctica |
publisher |
Victoria University of Wellington |
publishDate |
2013 |
url |
http://researcharchive.vuw.ac.nz/handle/10063/3067 |
long_lat |
ENVELOPE(163.850,163.850,-77.483,-77.483) ENVELOPE(163.450,163.450,-77.467,-77.467) ENVELOPE(166.500,166.500,-78.000,-78.000) ENVELOPE(163.567,163.567,-77.300,-77.300) ENVELOPE(163.000,163.000,-77.617,-77.617) |
geographic |
Bernacchi Cape Bernacchi McMurdo Ice Shelf McMurdo Sound Ross Sea Spike Cape Taylor Valley |
geographic_facet |
Bernacchi Cape Bernacchi McMurdo Ice Shelf McMurdo Sound Ross Sea Spike Cape Taylor Valley |
genre |
Antarc* Antarctica Ice Shelf McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice |
genre_facet |
Antarc* Antarctica Ice Shelf McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice |
op_relation |
http://researcharchive.vuw.ac.nz/handle/10063/3067 |
_version_ |
1774294307813982208 |