DOI: 10.5194/tc-14-2647-2020
论文题名: A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3He, 10Be, 21Ne, and 26Al
作者: Balter-Kennedy A. ; Bromley G. ; Balco G. ; Thomas H. ; Jackson M.S.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 8 起始页码: 2647
结束页码: 2672
语种: 英语
英文关键词: aluminum
; beryllium isotope
; cosmogenic radionuclide
; glacioisostasy
; helium isotope
; historical record
; Miocene
; moraine
; neon
; paleoclimate
; paleoenvironment
; Pleistocene
; Pliocene
; Antarctic Ice Sheet
; Antarctica
; East Antarctic Ice Sheet
; East Antarctica
; Transantarctic Mountains
英文摘要: The distribution of moraines in the Transantarctic Mountains affords direct constraint of past ice-marginal positions of the East Antarctic Ice Sheet (EAIS). Here, we describe glacial geologic observations and cosmogenic-nuclide exposure ages from Roberts Massif, an ice-free area in the central Transantarctic Mountains. We measured cosmogenic 3He, 10Be, 21Ne, and 26Al in 168 dolerite and sandstone boulders collected from 24 distinct deposits. Our data show that a cold-based EAIS was present, in a configuration similar to today, for many periods over the last ∼ 14.5 Myr, including the mid-Miocene, late Pliocene, and early to Middle Pleistocene. Moraine ages at Roberts Massif increase with distance from, and elevation above, the modern ice margin, which is consistent with a persistent EAIS extent during glacial maxima and slow, isostatic uplift of the massif itself in response to trough incision by outlet glaciers.We also employ the exceptionally high cosmogenic-nuclide concentrations in several boulders, along with multi-isotope measurements in sandstone boulders, to infer extremely low erosion rates (≪5 cm Myr-1) over the period covered by our record. Although our data are not a direct measure of ice volume, the Roberts Massif glacial record indicates that the EAIS was present and similar to its current configuration during at least some periods when the global temperature was believed to be warmer and/or atmospheric CO2concentrations were likely higher than today. © 2020 American Society of Civil Engineers (ASCE). All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164401
Appears in Collections: 气候变化与战略
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作者单位: School of Earth and Climate Sciences, University of Maine, Orono, ME, United States; Climate Change Institute, University of Maine, Orono, ME, United States; Geography, National University of Ireland Galway, Galway, Ireland; Berkeley Geochronology Center, Berkeley, CA, United States
Recommended Citation:
Balter-Kennedy A.,Bromley G.,Balco G.,et al. A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3He, 10Be, 21Ne, and 26Al[J]. Cryosphere,2020-01-01,14(8)