Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge
Sea ice and icebergs are the dominant transport agents for sand-sized material to the central Arctic Ocean. However, few studies have investigated concurrent changes in the silt-sized fraction of Arctic sediments. Here we present an analysis of the coarse fraction content and silt grain size composi...
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Norwegian Polar Institute
2014
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ftdoajarticles:oai:doaj.org/article:d4681a33f2ce4b8ba3380c9fe879a6f2 2023-05-15T14:54:48+02:00 Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge Matt O'Regan Emma Sellén Martin Jakobsson 2014-06-01T00:00:00Z https://doi.org/10.3402/polar.v33.23672 https://doaj.org/article/d4681a33f2ce4b8ba3380c9fe879a6f2 EN eng Norwegian Polar Institute http://www.polarresearch.net/index.php/polar/article/download/23672/pdf_1 https://doaj.org/toc/1751-8369 1751-8369 doi:10.3402/polar.v33.23672 https://doaj.org/article/d4681a33f2ce4b8ba3380c9fe879a6f2 Polar Research, Vol 33, Iss 0, Pp 1-12 (2014) Pleistocene Lomonosov Ridge grain size sea ice Environmental sciences GE1-350 Oceanography GC1-1581 article 2014 ftdoajarticles https://doi.org/10.3402/polar.v33.23672 2022-12-31T08:21:06Z Sea ice and icebergs are the dominant transport agents for sand-sized material to the central Arctic Ocean. However, few studies have investigated concurrent changes in the silt-sized fraction of Arctic sediments. Here we present an analysis of the coarse fraction content and silt grain size composition from middle and late Quaternary sediments recovered from the Lomonosov Ridge, in the central Arctic Ocean. A significant shift in the grain size record occurs at the marine isotope stage (MIS) 6/7 boundary, where larger amplitude variability in the sand fraction is seen in glacial and stadial periods. Below the MIS6/7 boundary, variations in the coarse fraction content are less pronounced, but prominent changes in the silt size fraction appear to define glacial and interglacial periods. Throughout the record, the percent weight of sortable silt in the fine fraction (SS % wtfines), sortable silt mean size, and coarse silt content all increase as the >63 µm % wt content increases. This is consistent with observations of grain size spectra obtained from modern sea-ice samples, and indicates a strong overprint from sea ice on the silt distribution. The mechanism by which this sea-ice signal is preserved in the sediments across glacial and interglacial periods remains unclear. We suggest that the coarsening of silt-sized material during glacial periods could be attributed to either the entrainment of larger size fractions during suspension/anchor ice formation when sea levels are lowered, or diminished input and advection of fine fraction material during glacial periods. Article in Journal/Newspaper Arctic Arctic Ocean Iceberg* Lomonosov Ridge Polar Research Sea ice Directory of Open Access Journals: DOAJ Articles Arctic Arctic Ocean Polar Research 33 1 23672 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Pleistocene Lomonosov Ridge grain size sea ice Environmental sciences GE1-350 Oceanography GC1-1581 |
spellingShingle |
Pleistocene Lomonosov Ridge grain size sea ice Environmental sciences GE1-350 Oceanography GC1-1581 Matt O'Regan Emma Sellén Martin Jakobsson Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge |
topic_facet |
Pleistocene Lomonosov Ridge grain size sea ice Environmental sciences GE1-350 Oceanography GC1-1581 |
description |
Sea ice and icebergs are the dominant transport agents for sand-sized material to the central Arctic Ocean. However, few studies have investigated concurrent changes in the silt-sized fraction of Arctic sediments. Here we present an analysis of the coarse fraction content and silt grain size composition from middle and late Quaternary sediments recovered from the Lomonosov Ridge, in the central Arctic Ocean. A significant shift in the grain size record occurs at the marine isotope stage (MIS) 6/7 boundary, where larger amplitude variability in the sand fraction is seen in glacial and stadial periods. Below the MIS6/7 boundary, variations in the coarse fraction content are less pronounced, but prominent changes in the silt size fraction appear to define glacial and interglacial periods. Throughout the record, the percent weight of sortable silt in the fine fraction (SS % wtfines), sortable silt mean size, and coarse silt content all increase as the >63 µm % wt content increases. This is consistent with observations of grain size spectra obtained from modern sea-ice samples, and indicates a strong overprint from sea ice on the silt distribution. The mechanism by which this sea-ice signal is preserved in the sediments across glacial and interglacial periods remains unclear. We suggest that the coarsening of silt-sized material during glacial periods could be attributed to either the entrainment of larger size fractions during suspension/anchor ice formation when sea levels are lowered, or diminished input and advection of fine fraction material during glacial periods. |
format |
Article in Journal/Newspaper |
author |
Matt O'Regan Emma Sellén Martin Jakobsson |
author_facet |
Matt O'Regan Emma Sellén Martin Jakobsson |
author_sort |
Matt O'Regan |
title |
Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge |
title_short |
Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge |
title_full |
Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge |
title_fullStr |
Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge |
title_full_unstemmed |
Middle to late Quaternary grain size variations and sea-ice rafting on the Lomonosov Ridge |
title_sort |
middle to late quaternary grain size variations and sea-ice rafting on the lomonosov ridge |
publisher |
Norwegian Polar Institute |
publishDate |
2014 |
url |
https://doi.org/10.3402/polar.v33.23672 https://doaj.org/article/d4681a33f2ce4b8ba3380c9fe879a6f2 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Iceberg* Lomonosov Ridge Polar Research Sea ice |
genre_facet |
Arctic Arctic Ocean Iceberg* Lomonosov Ridge Polar Research Sea ice |
op_source |
Polar Research, Vol 33, Iss 0, Pp 1-12 (2014) |
op_relation |
http://www.polarresearch.net/index.php/polar/article/download/23672/pdf_1 https://doaj.org/toc/1751-8369 1751-8369 doi:10.3402/polar.v33.23672 https://doaj.org/article/d4681a33f2ce4b8ba3380c9fe879a6f2 |
op_doi |
https://doi.org/10.3402/polar.v33.23672 |
container_title |
Polar Research |
container_volume |
33 |
container_issue |
1 |
container_start_page |
23672 |
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1766326542942601216 |