| DOI | 10.1038/s41561-021-00745-w
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| Hydrological impact of Middle Miocene Antarctic ice-free areas coupled to deep ocean temperatures |
| Bradshaw C.D.; Langebroek P.M.; Lear C.H.; Lunt D.J.; Coxall H.K.; Sosdian S.M.; de Boer A.M.
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| 发表日期 | 2021
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| ISSN | 17520894
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| 起始页码 | 429
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| 结束页码 | 436
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| 卷号 | 14期号:6 |
| 英文摘要 | Oxygen isotopes from ocean sediments (δ18O) used to reconstruct past continental ice volumes additionally record deep water temperatures (DWTs). Traditionally, these are assumed to be coupled (ice-volume changes cause DWT changes). However, δ18O records during peak Middle Miocene warmth (~16–15 million years ago) document large rapid fluctuations (~1–1.5‰) difficult to explain as huge Antarctic ice sheet (AIS) volume changes. Here, using climate modelling and data comparisons, we show DWTs are coupled to AIS spatial extent, not volume, because Antarctic albedo changes modify the hydrological cycle, affecting Antarctic deep water production regions. We suggest the Middle Miocene AIS had retreated substantially from previous Oligocene maxima. The residual ice sheet varied spatially more rapidly on orbital timescales than previously thought, enabling large DWT swings (up to 4 °C). When Middle Miocene warmth terminated (~13 million years ago) and a continent-scale AIS had stabilized, further ice-volume changes were predominantly in height rather than extent, with little impact on DWT. Our findings imply a shift in ocean sensitivity to ice-sheet changes occurs when AIS retreat exposes previously ice-covered land; associated feedbacks could reduce the Earth system’s ability to maintain a large AIS. This demonstrates ice-sheet changes should be characterized not only by ice volume but also by spatial extent. © 2021, Crown. |
| 英文关键词 | albedo; climate modeling; deep sea; deep water; ice sheet; Miocene; spatial analysis |
| 语种 | 英语
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| 来源期刊 | Nature Geoscience
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| 文献类型 | 期刊论文
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| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/206864
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| 作者单位 | Met Office Hadley Centre, Fitzroy Road, Exeter, United Kingdom; The Global Systems Institute, University of Exeter, Exeter, United Kingdom; BRIDGE, School of Geographical Sciences, University of Bristol, Bristol, United Kingdom; Department of Geological Sciences, Stockholm University, Stockholm, Sweden; NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, Bergen, Norway; School of Earth and Environmental Sciences, Cardiff University, Cardiff, United Kingdom
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推荐引用方式
GB/T 7714 |
Bradshaw C.D.,Langebroek P.M.,Lear C.H.,et al. Hydrological impact of Middle Miocene Antarctic ice-free areas coupled to deep ocean temperatures[J],2021,14(6).
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| APA |
Bradshaw C.D..,Langebroek P.M..,Lear C.H..,Lunt D.J..,Coxall H.K..,...&de Boer A.M..(2021).Hydrological impact of Middle Miocene Antarctic ice-free areas coupled to deep ocean temperatures.Nature Geoscience,14(6).
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| MLA |
Bradshaw C.D.,et al."Hydrological impact of Middle Miocene Antarctic ice-free areas coupled to deep ocean temperatures".Nature Geoscience 14.6(2021).
|
