气候变化领域集成服务门户(CCPortal): Evolution of the early Antarctic ice ages

CCPortal

DOI	10.1073/pnas.1615440114
	Evolution of the early Antarctic ice ages
	Liebrand D.; De Bakker A.T.M.; Beddow H.M.; Wilson P.A.; Bohaty S.M.; Ruessink G.; Pälike H.; Batenburg S.J.; Hilgen F.J.; Hodell D.A.; Huck C.E.; Kroon D.; Raffi I.; Saes M.J.M.; Van Dijk A.E.; Lourens L.J.
发表日期	2017
ISSN	0027-8424
起始页码	3867
结束页码	3872
卷号	114 期号:15
英文摘要	Understanding the stability of the early Antarctic ice cap in the geological past is of societal interest because present-day atmospheric CO2 concentrations have reached values comparable to those estimated for the Oligocene and the Early Miocene epochs. Here we analyze a new high-resolution deep-sea oxygen isotope (δ18O) record from the South Atlantic Ocean spanning an interval between 30.1 My and 17.1 My ago. The record displays major oscillations in deep-sea temperature and Antarctic ice volume in response to the ∼110-ky eccentricity modulation of precession. Conservative minimum ice volume estimates show that waxing and waning of at least ∼85 to 110% of the volume of the present East Antarctic Ice Sheet is required to explain many of the ∼110-ky cycles. Antarctic ice sheets were typically largest during repeated glacial cycles of the mid-Oligocene (∼28.0 My to ∼26.3 My ago) and across the Oligocene−Miocene Transition (∼23.0 My ago). However, the high-amplitude glacial−interglacial cycles of the mid-Oligocene are highly symmetrical, indicating a more direct response to eccentricity modulation of precession than their Early Miocene counterparts, which are distinctly asymmetrical—indicative of prolonged ice buildup and delayed, but rapid, glacial terminations. We hypothesize that the long-term transition to a warmer climate state with sawtooth-shaped glacial cycles in the Early Miocene was brought about by subsidence and glacial erosion in West Antarctica during the Late Oligocene and/or a change in the variability of atmospheric CO2 levels on astronomical time scales that is not yet captured in existing proxy reconstructions. © 2017, National Academy of Sciences. All rights reserved.
英文关键词	Bispectral analysis; Early Antarctic ice sheet; Glacial−interglacial cycle geometries; Oligocene−Miocene; Unipolar icehouse
语种	英语
scopus关键词	oxygen; Article; Atlantic Ocean; atmosphere; controlled study; deep sea; evolution; glacial period; ice age; ice sheet; interglacial; Miocene; Oligocene; oscillation; polar ice cap; priority journal; temperature; volume
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158897
作者单位	Liebrand, D., National Oceanography Centre Southampton, University of Southampton, Southampton, SO14 3ZH, United Kingdom; De Bakker, A.T.M., Department of Physical Geography, Faculty of Geosciences, Utrecht University, Utrecht, 3508 TC, Netherlands, Littoral Environnement et Sociétés, Université de La Rochelle, La Rochelle, 17042, France; Beddow, H.M., Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, 3584 CD, Netherlands; Wilson, P.A., National Oceanography Centre Southampton, University of Southampton, Southampton, SO14 3ZH, United Kingdom; Bohaty, S.M., National Oceanography Centre Southampton, University of Southampton, Southampton, SO14 3ZH, United Kingdom; Ruessink, G., Department of Physical Geography, Faculty of Geosciences, Utrecht University, Utrecht, 3508 TC, Netherlands; Pälike, H., Center for Marine Environmental Sciences, University of Bremen, Bremen, 28359, Germany; Batenburg, S.J., Institute of Geosciences, Goethe-University Frankfurt am Main, Frankfurt, 60...
推荐引用方式 GB/T 7714	Liebrand D.,De Bakker A.T.M.,Beddow H.M.,et al. Evolution of the early Antarctic ice ages[J],2017,114(15).
APA	Liebrand D..,De Bakker A.T.M..,Beddow H.M..,Wilson P.A..,Bohaty S.M..,...&Lourens L.J..(2017).Evolution of the early Antarctic ice ages.Proceedings of the National Academy of Sciences of the United States of America,114(15).
MLA	Liebrand D.,et al."Evolution of the early Antarctic ice ages".Proceedings of the National Academy of Sciences of the United States of America 114.15(2017).