A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada.
An important source of information about climate change comes from sedimentary deposits from the arctic region. However, there are few lacustrine fossil records from the central mid Arctic region of Canada. A 485 cm sediment core, from a lake unofficially called JR01, Boothia Peninsula, Nunavut, yie...
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ftunivottawa:oai:ruor.uottawa.ca:10393/6414 2023-05-15T14:51:58+02:00 A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada. LeBlanc, Michelle. Gajewski, Konrad 2002 81 p. application/pdf http://hdl.handle.net/10393/6414 https://doi.org/10.20381/ruor-11261 unknown University of Ottawa (Canada) Source: Masters Abstracts International, Volume: 41-05, page: 1404. 9780612765979 http://hdl.handle.net/10393/6414 http://dx.doi.org/10.20381/ruor-11261 Physical Geography Thesis 2002 ftunivottawa https://doi.org/10.20381/ruor-11261 2021-01-04T17:04:28Z An important source of information about climate change comes from sedimentary deposits from the arctic region. However, there are few lacustrine fossil records from the central mid Arctic region of Canada. A 485 cm sediment core, from a lake unofficially called JR01, Boothia Peninsula, Nunavut, yielded a high-resolution diatom record. Five radiocarbon dates provided the chronology. Three distinct zones are revealed in the relative percent abundance and diatom concentration diagrams. A more diverse and productive flora in the first zone implies warmer temperatures in the middle Holocene. A complete shift in diatom composition to a predominantly Fragilaria flora and a reduction in diversity and production suggests a cooler climate in this region after approximately 4360 years B.P. Smaller-scale climatic trends, such as the Little Ice Age (LIA) (ca. 550--150 yr. B.P.) and the Medieval Warm Period (ca. 1000--700 yr. B.P.), caused shifts in the diatom flora and production. Subtle shifts in floristic diversity within the LIA may reflect climate variability at a decadal scale. This variability is also recorded in other high-resolution paleoclimate records from the Arctic. A gradual shift to a more diverse and productive flora in the last 180 years B.P. (1790 years A.D.) suggests a response to the recent warming trend. This study permits us to address ambiguities with respect to the timing, the geographic extent and the severity of the recent warming. Changes in total diatom concentrations, magnetic susceptibility, organic and carbonate content may also reflect changes in the diatom assemblages and indicate shifts in vegetation, soil erosion, or in hydrology from the surrounding catchment. The morphological variance of Fragilaria and other taxonomy issues are also discussed. Thesis Arctic Boothia Peninsula Climate change Magnetic susceptibility Nunavut uO Research (University of Ottawa - uOttawa) Arctic Boothia Peninsula ENVELOPE(-94.000,-94.000,71.001,71.001) Canada Nunavut |
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uO Research (University of Ottawa - uOttawa) |
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ftunivottawa |
language |
unknown |
topic |
Physical Geography |
spellingShingle |
Physical Geography LeBlanc, Michelle. A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada. |
topic_facet |
Physical Geography |
description |
An important source of information about climate change comes from sedimentary deposits from the arctic region. However, there are few lacustrine fossil records from the central mid Arctic region of Canada. A 485 cm sediment core, from a lake unofficially called JR01, Boothia Peninsula, Nunavut, yielded a high-resolution diatom record. Five radiocarbon dates provided the chronology. Three distinct zones are revealed in the relative percent abundance and diatom concentration diagrams. A more diverse and productive flora in the first zone implies warmer temperatures in the middle Holocene. A complete shift in diatom composition to a predominantly Fragilaria flora and a reduction in diversity and production suggests a cooler climate in this region after approximately 4360 years B.P. Smaller-scale climatic trends, such as the Little Ice Age (LIA) (ca. 550--150 yr. B.P.) and the Medieval Warm Period (ca. 1000--700 yr. B.P.), caused shifts in the diatom flora and production. Subtle shifts in floristic diversity within the LIA may reflect climate variability at a decadal scale. This variability is also recorded in other high-resolution paleoclimate records from the Arctic. A gradual shift to a more diverse and productive flora in the last 180 years B.P. (1790 years A.D.) suggests a response to the recent warming trend. This study permits us to address ambiguities with respect to the timing, the geographic extent and the severity of the recent warming. Changes in total diatom concentrations, magnetic susceptibility, organic and carbonate content may also reflect changes in the diatom assemblages and indicate shifts in vegetation, soil erosion, or in hydrology from the surrounding catchment. The morphological variance of Fragilaria and other taxonomy issues are also discussed. |
author2 |
Gajewski, Konrad |
format |
Thesis |
author |
LeBlanc, Michelle. |
author_facet |
LeBlanc, Michelle. |
author_sort |
LeBlanc, Michelle. |
title |
A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada. |
title_short |
A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada. |
title_full |
A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada. |
title_fullStr |
A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada. |
title_full_unstemmed |
A diatom-based Holocene paleoenvironmental record from a lake on Boothia Peninsula, central mid-Arctic, Nunavut, Canada. |
title_sort |
diatom-based holocene paleoenvironmental record from a lake on boothia peninsula, central mid-arctic, nunavut, canada. |
publisher |
University of Ottawa (Canada) |
publishDate |
2002 |
url |
http://hdl.handle.net/10393/6414 https://doi.org/10.20381/ruor-11261 |
long_lat |
ENVELOPE(-94.000,-94.000,71.001,71.001) |
geographic |
Arctic Boothia Peninsula Canada Nunavut |
geographic_facet |
Arctic Boothia Peninsula Canada Nunavut |
genre |
Arctic Boothia Peninsula Climate change Magnetic susceptibility Nunavut |
genre_facet |
Arctic Boothia Peninsula Climate change Magnetic susceptibility Nunavut |
op_relation |
Source: Masters Abstracts International, Volume: 41-05, page: 1404. 9780612765979 http://hdl.handle.net/10393/6414 http://dx.doi.org/10.20381/ruor-11261 |
op_doi |
https://doi.org/10.20381/ruor-11261 |
_version_ |
1766323100191817728 |