| PALEOLIMNOLOGY |
A 2000 year midge-based paleotemperature reconstruction from the Canadian Arctic Archipelago.
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Porinchu, D.F.,MacDonald, G.M.,Rolland, N. 2008 A 2000 year midge-based paleotemperature reconstruction from the Canadian
Arctic Archipelago. Journal of Paleolimnology
| Data Coverage |
North: 68.657 * South: 68.657 |
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West: -105.357 * East: -105.357 |
Start Year: 32 cal yr BP * End Year: 1999 cal yr BP
Data: Please Cite Data Contributors!
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Summary: A lake sediment core recovered from Lake V57 on Victoria Island,
Nunavut, Canada, spanning the last 2000 years, was analyzed for
sub-fossil midge remains and organic-matter content (estimated by
loss-on-ignition (LOI)). Significant changes in midge community
composition occurred during the last 2000 years, with a distinct
midge community appearing after 1600 AD. The chironomid community
between 0 and 1600 AD was dominated by Heterotrissocladius,
Tanytarsus, Abiskomyia, and Paracladius. At approximately 1600 AD,
Heterotrissocladius decreased in relative abundance and taxa such
as Corynocera ambigua, C. oliveri, Psectrocladius sordidellus type,
and Pentanneurini increased in relative abundance.
Previously published midge-based inference models for average
July air temperature (AJAT) and summer surface-water temperature
(SSWT) were applied to the subfossil midge stratigraphy.
The AJAT reconstruction indicates relatively cool conditions existed
between 1100 and 1600 AD, with exceptional warming occurring after
1600 AD, as lake productivity inferred from organic-matter content
increased concomitantly with midge-inferred AJAT and SSWT.
The cooler conditions between 1200 and 1600 AD, and the pattern
of warming over recent centuries inferred from Lake V57 is broadly
consistent with temperature-sensitive biogenic silica records from
other sites in the central Canadian Arctic and the treeline zone
to the south suggesting a regionally synchronous response to
climate forcing.
More Info on Paleolimnology |
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Complete XML Record: noaa-lake-6201
(Last Revised: 2009-02-11 )
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