Early Holocene ice on the Begguya plateau (Mt. Hunter, Alaska) revealed by ice core 14C age constraints
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Published:2023-09-15
Issue:9
Volume:17
Page:4007-4020
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ISSN:1994-0424
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Container-title:The Cryosphere
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language:en
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Short-container-title:The Cryosphere
Author:
Fang LingORCID, Jenk Theo M.ORCID, Winski DominicORCID, Kreutz KarlORCID, Brooks Hanna L., Erwin Emma, Osterberg Erich, Campbell Seth, Wake CameronORCID, Schwikowski MargitORCID
Abstract
Abstract. Investigating North Pacific climate variability during warm
intervals prior to the Common Era can improve our understanding of the
behavior of ocean–atmosphere teleconnections between low latitudes and the
Arctic under future warming scenarios. However, most of the existing ice
core records from the Alaskan and Yukon region only allow access to climate
information covering the last few centuries. Here we present a
surface-to-bedrock age scale for a 210 m long ice core recovered in 2013
from the summit plateau of Begguya (Mt. Hunter; Denali National Park,
Central Alaska). Combining dating by annual layer counting with absolute
dates from micro-radiocarbon dating, a continuous chronology for the entire
ice core archive was established using an ice flow model. Calibrated
14C ages from the deepest section (209.1 m, 7.7 to 9.0 ka cal BP)
indicate that basal ice on Begguya is at least of early Holocene origin. A
series of samples from a shallower depth interval (199.8 to 206.6 m) were
dated with near-uniform 14C ages (3 to 5 ka cal BP). Our results
suggest this may be related to an increase in annual net snow accumulation
rates over this period following the Northern Hemisphere Holocene Climate
Optimum (around 8 to 5 kyr BP). With absolute dates constraining the
timescale for the last >8 kyr BP, this paleo-archive will allow
future investigations of Holocene climate and the regional evolution of
spatial and temporal changes in atmospheric circulation and hydroclimate in
the North Pacific.
Funder
National Science Foundation
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Water Science and Technology
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