| PALEOLIMNOLOGY |
Sedimentary pellets as an ice-cover proxy in a High Arctic ice-covered lake.
Sedimentary pellets as an ice-cover proxy in a High Arctic ice-covered lake.
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Tomkins, J.D.,Lamoureux, S.F.,Antoniades, D.,Vincent, W.F. 2008 Sedimentary pellets as an ice-cover proxy in a High Arctic
ice-covered lake.
Sedimentary pellets as an ice-cover proxy in a High Arctic ice-covered lake. Journal of Paleolimnology
| Data Coverage |
North: 83 * South: 83 |
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West: -75.5 * East: -75.5 |
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Altitude: 4 m |
Start Year: 1017 cal yr BP * End Year: 2005 cal yr BP
Data: Please Cite Data Contributors!
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Summary: Sediment aggregates ("sedimentary pellets") within the sedimentary record
of Lake A (83°00'N, 75°30'W), Ellesmere Island, Canada, are used to construct
a 1000 year proxy record of ice-cover extent and dynamics on this perennially
ice-covered, High Arctic lake. These pellets are interpreted to form during
fall or early winter when littoral sediment adheres to ice forming around the
lake's periphery or during summer through the development of anchor ice.
The sediment likely collects in ice interstices and is concentrated in the
upper ice layers through summer surface ice melt and winter basal ice growth.
The pellets remain frozen in the ice until a summer or series of summers with
reduced ice cover allows for their deposition across the lake basin.
Sedimentary pellet frequency within multiple sediment cores is used to develop
a chronology of ice-cover fluctuations. This proxy ice-cover record is largely
corroborated by a record of unusual sedimentation in Lake A involving iron-rich,
dark-orange to red laminae overlying more diffuse laminae with a lighter hue.
This sediment sequence is hypothesized to represent years with reduced ice cover
through increased chemocline ventilation and iron deposition. During the past
millennium, the most notable period of inferred reduced ice cover is ca. 1891 AD
to present. Another period of ice cover mobility is suggested ca. 1582¿1774 AD,
while persistent ice cover is inferred during the 1800s and prior to 1582 AD.
The proxy ice-cover record corresponds well with most regional meltseason proxy
temperature and paleoecological records, especially during the 1800s and 1900s.
More Info on Paleolimnology |
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Complete XML Record: noaa-lake-6204
(Last Revised: 2009-02-11 )
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