DOI: 10.1016/j.quascirev.2013.06.024
Scopus记录号: 2-s2.0-84900463671
论文题名: Holocene fluctuations of Bregne ice cap, Scoresby Sund, east Greenland: A proxy for climate along the Greenland Ice Sheet margin
作者: Levy L.B. ; Kelly M.A. ; Lowell T.V. ; Hall B.L. ; Hempel L.A. ; Honsaker W.M. ; Lusas A.R. ; Howley J.A. ; Axford Y.L.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 92 起始页码: 357
结束页码: 368
语种: 英语
英文关键词: Greenland
; Greenland Ice Sheet
; Holocene
; Lake sediment cores
; Scoresby Sund
Scopus关键词: Climate change
; Glaciers
; Lakes
; Magnetic susceptibility
; Sediments
; Greenland
; Greenland Ice Sheet
; Holocenes
; Lake sediment cores
; Scoresby Sund
; Snow
; bedrock
; beryllium isotope
; climate variation
; cryosphere
; deglaciation
; GRIP
; Holocene
; ice cap
; ice margin
; ice sheet
; insolation
; lacustrine deposit
; lamination
; magnetic susceptibility
; moraine
; Northern Hemisphere
; paleoclimate
; proxy climate record
; reconstruction
; silt
; snow accumulation
; Arctic
; Bregne Ice Cap
; Greenland
; Greenland Ice Sheet
; Scoresby Sund
英文摘要: The Greenland Ice Sheet is a major component of the Arctic cryosphere and the magnitude of its response to future climate changes remains uncertain. Longer-term records of climate near the ice sheet margin provide information about natural climate variability and can be used to understand the causes of past changes in the Greenland Ice Sheet. As a proxy for Holocene climate near the ice sheet margin, we reconstruct the fluctuations of Bregne ice cap in the Scoresby Sund region of central east Greenland. Bregne is a small ice cap (2.5km2 in area) and responds sensitively to summer temperatures. We employ a multi-proxy approach to reconstruct the ice cap fluctuations using geomorphic mapping, 10Be ages of boulders and bedrock and lake sediment records.Past extents of Bregne ice cap are marked by moraines and registered by sediments in downvalley lakes. 10Be ages of bedrock and boulders outboard of the moraines indicate that Bregne ice cap was within ~250m of its present-day limit by at least 10.7ka. Multi-proxy data from sediments in Two Move lake, located downvalley from Bregne ice cap, indicate that the ice cap likely completely disappeared during early and middle Holocene time. Increasing magnetic susceptibility and percent clastic material from ~6.5 to ~1.9calkaBP in Two Move lake sediments suggest progressively colder conditions and increased snow accumulation on the highlands west of the lake. Laminated silt deposited at ~2.6calkaBP and ~1.9calkaBP to present registers the onset and persistence of Bregne ice cap during the late Holocene. 10Be ages of boulders on an unweathered, unvegetated moraine in the Bregne ice cap forefield range from 0.74 to 9.60ka. The youngest 10Be age (0.74ka) likely represents the age of the moraine whereas older ages may be due to 10Be inherited from prior periods of exposure. This late Holocene moraine marks the second largest advance of the ice cap since deglaciation of the region at the end of the last ice age. The oldest moraine in the forefield dates to ≤2.6calkaBP. The fluctuations of Bregne ice cap were likely influenced by Northern Hemisphere summer insolation throughout the Holocene and abrupt late Holocene cold events. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60306
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: Department of Earth Sciences, Dartmouth College, Hanover, NH, United States; Department of Geology, University of Cincinnati, Cincinnati, OH, United States; School of Earth and Climate Sciences and Climate Change Institute, University of Maine, Orono, ME, United States; Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, United States
Recommended Citation:
Levy L.B.,Kelly M.A.,Lowell T.V.,et al. Holocene fluctuations of Bregne ice cap, Scoresby Sund, east Greenland: A proxy for climate along the Greenland Ice Sheet margin[J]. Quaternary Science Reviews,2014-01-01,92