A late Quaternary paleotemperature record from Hanging Lake, northern Yukon Territory, eastern Beringia

The late Quaternary paleoclimate of eastern Beringia has primarily been studied by drawing qualitative inferences from vegetation shifts. To quantitatively reconstruct summer temperatures, we analyzed lake sediments for fossil chironomids, and additionally we analyzed the sediments for fossil pollen and organic carbon content. A comparison with the delta O-18 record from Greenland indicates that the general climatic development of the region throughout the last glaciation-Holocene transition differed from that of the North Atlantic region. Between similar to 17 and 15 ka, mean July air temperature was on average 5 degrees C colder than modern, albeit a period of near-modern temperature at similar to 16.5 ka. Total pollen accumulation rates ranged between similar to 180 and 1200 grains cm(-2) yr(-1). At similar to 15 ka, approximately coeval with the Bolling interstadial, temperatures again reached modern values. At similar to 14 ka, nearly 1000 yr after warming began, Betula pollen percentages increased substantially and mark the transition to shrub-dominated pollen contributors. Chironomid-based inferences suggest no evidence of the Younger Dryas stade and only subtle evidence of an early Holocene thermal maximum, as temperatures from similar to 15 ka to the late Holocene were relatively stable. The most recognizable climatic oscillation of the Holocene occurred from similar to 4.5 to 2 ka. (C) 2009 University of Washington. Published by Elsevier Inc. All rights reserved.