The Medieval Warm/Little Ice Age Transition as Recorded by Ice Caps in East Greenland
Abstract
The spatial-temporal distribution of late Holocene temperature changes over the last 2000 yr is still being defined. The high Arctic is often represented by the borehole tem-perature records from GISP and Dye 3. These both show a distinct, but different magni-tude, Medieval warm interval from ~500 to ~1200 AD, with two cold intervals after 1500 AD. However small glaciers in the high Arctic appear reflect a more complex late Holo-cene pattern. On the eastern coast of Greenland two ice caps record a warm interval from 400 AD to 600 AD but cooling after that. These ice caps, Istorvet ,on the coast beside the cold East Greenland Current, and Bregne ice cap, ~ 100 km inland, have yielded organic remains from > 50 sites. A preliminary interpretation is that the organic remains record the last time these ice caps were as small or smaller than the present configuration. Exposure ages show these ice caps reached their post glacial maximum extent within the last 1000 yr. The Istorvet ice cap is thought to show initial cooling at ~AD 884 and an advance to within 500 m of the Little Ice Age extent at AD 1022 and its fullest extent at 1125 AD. Core sediments suggest that extent was maintained until 1750 AD. Results from the inland site indicate a retracted ice cap from AD 1054 to 1393, followed by expansion. Although some of these events appear to have correlative events recorded in SST or sea ice near Iceland. Taken together they appear to have a different signature than lo-cations further south. This may indicate that temperature patterns at high latitudes are only partly coupled with those at lower latitudes.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMPP34A..05L
- Keywords:
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- 4926 PALEOCEANOGRAPHY / Glacial