1
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Donda F, Rebesco M, Kovacevic V, Silvano A, Bensi M, De Santis L, Rosenthal Y, Torricella F, Baradello L, Gei D, Leventer A, Post A, Leitchenkov G, Noble T, Zgur F, Cova A, O'Brien P, Romeo R. Footprint of sustained poleward warm water flow within East Antarctic submarine canyons. Nat Commun 2024; 15:6028. [PMID: 39019883 PMCID: PMC11254908 DOI: 10.1038/s41467-024-50160-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 06/25/2024] [Indexed: 07/19/2024] Open
Abstract
The intrusion of relatively warm water onto the continental shelf is widely recognized as a threat to Antarctic ice shelves and glaciers grounded below sea level, as enhanced ocean heat increases their basal melt. While the circulation of warm water has been documented on the East Antarctic continental shelf, the modes of warm water transport from the deep ocean onto the shelf are still uncertain. This makes predicting the future responses of major East Antarctic marine-grounded glaciers, such as Totten and Ninnis glaciers, particularly challenging. Here, we outline the key role of submarine canyons to convey southward flowing currents that transport warm Circumpolar Deep Water toward the East Antarctic shelf break, thus facilitating warm water intrusion on the continental shelf. Sediment drifts on the eastern flank of the canyons provide evidence for sustained southward-directed flows. These morpho-sedimentary features thus highlight areas potentially prone to enhanced ocean heat transport toward the continental shelf, with repercussions for past, present, and future glacial melting and consequent sea level rise.
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Affiliation(s)
- Federica Donda
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy.
| | - Michele Rebesco
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Vedrana Kovacevic
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Alessandro Silvano
- School of Ocean and Earth Science, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Manuel Bensi
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Laura De Santis
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Yair Rosenthal
- Department of Marine and Coastal Sciences, Rutgers, State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Fiorenza Torricella
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Luca Baradello
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Davide Gei
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Amy Leventer
- Geology Department, Colgate University, Hamilton, NY, 13346, USA
| | - Alix Post
- Geoscience Australia, GPO Box 378, Canberra, ACT, 2601, Australia
| | - German Leitchenkov
- The All-Russia Scientific Research Institute for Geology and Mineral Resources of the Ocean, St. Petersburg, Russia
- Institute of Earth Sciences, St. Petersburg State University, 199034, St. Petersburg, Russia
| | - Taryn Noble
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, 7001, Australia
| | - Fabrizio Zgur
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Andrea Cova
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
| | - Philip O'Brien
- Earth and Environmental Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Roberto Romeo
- National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy
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2
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Hutchinson DK, Menviel L, Meissner KJ, Hogg AM. East Antarctic warming forced by ice loss during the Last Interglacial. Nat Commun 2024; 15:1026. [PMID: 38310088 PMCID: PMC10838265 DOI: 10.1038/s41467-024-45501-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 01/26/2024] [Indexed: 02/05/2024] Open
Abstract
During the Last Interglacial (LIG; 129-116 thousand years before present), the Antarctic ice sheet (AIS) was 1 to 7 m sea level equivalent smaller than at pre-industrial. Here, we assess the climatic impact of partial AIS melting at the LIG by forcing a coupled climate model with a smaller AIS and the equivalent meltwater input around the Antarctic coast. We find that changes in surface elevation induce surface warming over East Antarctica of 2 to 4 °C, and sea surface temperature (SST) increases in the Weddell and Ross Seas by up to 2 °C. Meltwater forcing causes a high latitude SST decrease and a subsurface (100-500 m) ocean temperature increase by up to 2 °C in the Ross Sea. Our results suggest that the combination of a smaller AIS and enhanced meltwater input leads to a larger sub-surface warming than meltwater alone and induces further Antarctic warming than each perturbation separately.
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Affiliation(s)
- David K Hutchinson
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia.
- The Australian Centre for Excellence in Antarctic Science, University of New South Wales, Sydney, NSW, Australia.
| | - Laurie Menviel
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- The Australian Centre for Excellence in Antarctic Science, University of New South Wales, Sydney, NSW, Australia
| | - Katrin J Meissner
- Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
| | - Andrew McC Hogg
- ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, NSW, Australia
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
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3
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Richards FD, Coulson SL, Hoggard MJ, Austermann J, Dyer B, Mitrovica JX. Geodynamically corrected Pliocene shoreline elevations in Australia consistent with midrange projections of Antarctic ice loss. SCIENCE ADVANCES 2023; 9:eadg3035. [PMID: 37976352 PMCID: PMC10656067 DOI: 10.1126/sciadv.adg3035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 10/18/2023] [Indexed: 11/19/2023]
Abstract
The Mid-Pliocene represents the most recent interval in Earth history with climatic conditions similar to those expected in the coming decades. Mid-Pliocene sea level estimates therefore provide important constraints on projections of future ice sheet behavior and sea level change but differ by tens of meters due to local distortion of paleoshorelines caused by mantle dynamics. We combine an Australian sea level marker compilation with geodynamic simulations and probabilistic inversions to quantify and remove these post-Pliocene vertical motions at continental scale. Dynamic topography accounts for most of the observed sea level marker deflection, and correcting for this effect and glacial isostatic adjustment yields a Mid-Pliocene global mean sea level of +16.0 (+10.4 to +21.5) m (50th/16th to 84th percentiles). Recalibration of recent high-end sea level projections using this revised estimate implies a more stable Antarctic Ice Sheet under future warming scenarios, consistent with midrange forecasts of sea level rise that do not incorporate a marine ice cliff instability.
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Affiliation(s)
- Fred D. Richards
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Sophie L. Coulson
- Fluid Dynamics and Solid Mechanics Group, Los Alamos National Laboratory, Los Alamos, NM, USA
- Department of Earth Sciences, University of New Hampshire, Durham, NH, USA
| | - Mark J. Hoggard
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | | | - Blake Dyer
- School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, Canada
| | - Jerry X. Mitrovica
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA
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4
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Li T, Robinson LF, MacGilchrist GA, Chen T, Stewart JA, Burke A, Wang M, Li G, Chen J, Rae JWB. Enhanced subglacial discharge from Antarctica during meltwater pulse 1A. Nat Commun 2023; 14:7327. [PMID: 37957152 PMCID: PMC10643554 DOI: 10.1038/s41467-023-42974-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Subglacial discharge from the Antarctic Ice Sheet (AIS) likely played a crucial role in the loss of the ice sheet and the subsequent rise in sea level during the last deglaciation. However, no direct proxy is currently available to document subglacial discharge from the AIS, which leaves significant gaps in our understanding of the complex interactions between subglacial discharge and ice-sheet stability. Here we present deep-sea coral 234U/238U records from the Drake Passage in the Southern Ocean to track subglacial discharge from the AIS. Our findings reveal distinctively higher seawater 234U/238U values from 15,400 to 14,000 years ago, corresponding to the period of the highest iceberg-rafted debris flux and the occurrence of the meltwater pulse 1A event. This correlation suggests a causal link between enhanced subglacial discharge, synchronous retreat of the AIS, and the rapid rise in sea levels. The enhanced subglacial discharge and subsequent AIS retreat appear to have been preconditioned by a stronger and warmer Circumpolar Deep Water, thus underscoring the critical role of oceanic heat in driving major ice-sheet retreat.
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Affiliation(s)
- Tao Li
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China.
- School of Earth Sciences, University of Bristol, Bristol, UK.
- Department of Earth and Planetary Sciences, Nanjing University, Nanjing, China.
| | - Laura F Robinson
- School of Earth Sciences, University of Bristol, Bristol, UK
- Department of Environment and Geography, University of York, York, UK
| | - Graeme A MacGilchrist
- Program in Atmospheric and Oceanic Science, Princeton University, Princeton, NJ, USA
- School of Earth and Environmental Sciences, University of St Andrews, St Andrews, UK
| | - Tianyu Chen
- Department of Earth and Planetary Sciences, Nanjing University, Nanjing, China
| | | | - Andrea Burke
- School of Earth and Environmental Sciences, University of St Andrews, St Andrews, UK
| | - Maoyu Wang
- Department of Earth and Planetary Sciences, Nanjing University, Nanjing, China
| | - Gaojun Li
- Department of Earth and Planetary Sciences, Nanjing University, Nanjing, China
| | - Jun Chen
- Department of Earth and Planetary Sciences, Nanjing University, Nanjing, China
| | - James W B Rae
- School of Earth and Environmental Sciences, University of St Andrews, St Andrews, UK
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5
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Jamieson SSR, Ross N, Paxman GJG, Clubb FJ, Young DA, Yan S, Greenbaum J, Blankenship DD, Siegert MJ. An ancient river landscape preserved beneath the East Antarctic Ice Sheet. Nat Commun 2023; 14:6507. [PMID: 37875503 PMCID: PMC10597991 DOI: 10.1038/s41467-023-42152-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 10/02/2023] [Indexed: 10/26/2023] Open
Abstract
The East Antarctic Ice Sheet (EAIS) has its origins ca. 34 million years ago. Since then, the impact of climate change and past fluctuations in the EAIS margin has been reflected in periods of extensive vs. restricted ice cover and the modification of much of the Antarctic landscape. Resolving processes of landscape evolution is therefore critical for establishing ice sheet history, but it is rare to find unmodified landscapes that record past ice conditions. Here, we discover an extensive relic pre-glacial landscape preserved beneath the central EAIS despite millions of years of ice cover. The landscape was formed by rivers prior to ice sheet build-up but later modified by local glaciation before being dissected by outlet glaciers at the margin of a restricted ice sheet. Preservation of the relic surfaces indicates an absence of significant warm-based ice throughout their history, suggesting any transitions between restricted and expanded ice were rapid.
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Affiliation(s)
| | - Neil Ross
- School of Geography, Politics and Sociology, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Guy J G Paxman
- Department of Geography, Durham University, Durham, DH1 3LE, UK
| | - Fiona J Clubb
- Department of Geography, Durham University, Durham, DH1 3LE, UK
| | - Duncan A Young
- University of Texas Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, USA
| | - Shuai Yan
- University of Texas Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, USA
- Department of Geosciences, Jackson School of Geosciences, University of Texas at Austin, Austin, USA
| | - Jamin Greenbaum
- Scripps Institute for Oceanography, University of California at San Diego, San Diego, USA
| | - Donald D Blankenship
- University of Texas Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, USA
| | - Martin J Siegert
- Tremough House, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
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6
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Iizuka M, Seki O, Wilson DJ, Suganuma Y, Horikawa K, van de Flierdt T, Ikehara M, Itaki T, Irino T, Yamamoto M, Hirabayashi M, Matsuzaki H, Sugisaki S. Multiple episodes of ice loss from the Wilkes Subglacial Basin during the Last Interglacial. Nat Commun 2023; 14:2129. [PMID: 37072396 PMCID: PMC10113383 DOI: 10.1038/s41467-023-37325-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 03/10/2023] [Indexed: 04/20/2023] Open
Abstract
The Last Interglacial (LIG: 130,000-115,000 years ago) was a period of warmer global mean temperatures and higher and more variable sea levels than the Holocene (11,700-0 years ago). Therefore, a better understanding of Antarctic ice-sheet dynamics during this interval would provide valuable insights for projecting sea-level change in future warming scenarios. Here we present a high-resolution record constraining ice-sheet changes in the Wilkes Subglacial Basin (WSB) of East Antarctica during the LIG, based on analysis of sediment provenance and an ice melt proxy in a marine sediment core retrieved from the Wilkes Land margin. Our sedimentary records, together with existing ice-core records, reveal dynamic fluctuations of the ice sheet in the WSB, with thinning, melting, and potentially retreat leading to ice loss during both early and late stages of the LIG. We suggest that such changes along the East Antarctic Ice Sheet margin may have contributed to fluctuating global sea levels during the LIG.
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Affiliation(s)
- Mutsumi Iizuka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
- Geological Survey of Japan, The National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.
| | - Osamu Seki
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
| | - David J Wilson
- London Geochemistry and Isotope Centre (LOGIC), Institute of Earth and Planetary Sciences, University College London and Birkbeck, University of London, London, UK
| | - Yusuke Suganuma
- National Institute of Polar Research, Tachikawa, Japan
- Department of Polar Science, School of Multidisciplinary Sciences, The Graduate University for Advanced Studies (SOKENDAI), Tachikawa, Japan
| | - Keiji Horikawa
- Faculty of Science, Academic Assembly, University of Toyama, Gofuku, Japan
| | - Tina van de Flierdt
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Minoru Ikehara
- Marine Core Research Institute (MaCRI), Kochi University, Nankoku, Japan
| | - Takuya Itaki
- Geological Survey of Japan, The National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Tomohisa Irino
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
| | - Masanobu Yamamoto
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
| | | | - Hiroyuki Matsuzaki
- Micro Analysis Laboratory, Tandem accelerator (MALT), The University of Tokyo, Bunkyo, Japan
| | - Saiko Sugisaki
- Geological Survey of Japan, The National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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7
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Jordan JR, Miles BWJ, Gudmundsson GH, Jamieson SSR, Jenkins A, Stokes CR. Increased warm water intrusions could cause mass loss in East Antarctica during the next 200 years. Nat Commun 2023; 14:1825. [PMID: 37005432 PMCID: PMC10067810 DOI: 10.1038/s41467-023-37553-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 03/22/2023] [Indexed: 04/04/2023] Open
Abstract
The East Antarctic Ice Sheet (EAIS) is currently surrounded by relatively cool water, but climatic shifts have the potential to increase basal melting via intrusions of warm modified Circumpolar Deep Water (mCDW) onto the continental shelf. Here we use an ice sheet model to show that under the current ocean regime, with only limited intrusions of mCDW, the EAIS will likely gain mass over the next 200 years due to the increased precipitation from a warming atmosphere outweighing increased ice discharge due to ice-shelf melting. However, if the ocean regime were to become dominated by greater mCDW intrusions, the EAIS would have a negative mass balance, contributing up to 48 mm of SLE over this time period. Our modelling finds George V Land to be particularly at risk to increased ocean induced melting. With warmer oceans, we also find that a mid range RCP4.5 emissions scenario is likely to result in a more negative mass balance than a high RCP8.5 emissions scenario, as the relative difference between increased precipitation due to a warming atmosphere and increased ice discharge due to a warming ocean is more negative in the mid range RCP4.5 emission scenario.
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Affiliation(s)
- James R Jordan
- Department of Geography and Environmental Sciences, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, UK.
- Laboratoire de Glaciologie, Université libre de Bruxelles (ULB), Brussels, Belgium.
| | - B W J Miles
- Department of Geography, Durham University, Durham, DH1 3LE, UK
- School of Geosciences, University of Edinburgh, Edinburgh, UK
| | - G H Gudmundsson
- Department of Geography and Environmental Sciences, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, UK
| | - S S R Jamieson
- Department of Geography, Durham University, Durham, DH1 3LE, UK
| | - A Jenkins
- Department of Geography and Environmental Sciences, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, UK
| | - C R Stokes
- Department of Geography, Durham University, Durham, DH1 3LE, UK
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8
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Edwards GH, Blackburn T, Piccione G, Tulaczyk S, Miller GH, Sikes C. Terrestrial evidence for ocean forcing of Heinrich events and subglacial hydrologic connectivity of the Laurentide Ice Sheet. SCIENCE ADVANCES 2022; 8:eabp9329. [PMID: 36260662 PMCID: PMC9581489 DOI: 10.1126/sciadv.abp9329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
During the last glacial period, the Laurentide Ice Sheet (LIS) underwent episodes of rapid iceberg discharge, recorded in ocean sediments as "Heinrich events" (HEs). Two competing models attempt to describe the stimulus for HEs via either internal ice sheet oscillations or external ocean-climate system forcing. We present a terrestrial record of HEs from the northeastern LIS that strongly supports ocean-climate forcing. Subglacial carbonate precipitates from Baffin Island record episodes of subglacial melting coincident with the three most recent HEs, resulting from acceleration of nearby marine-terminating ice streams. Synchronized ice stream acceleration over Baffin Island and Hudson Strait is inconsistent with internal ice sheet oscillations alone and indicates a shared ocean-climate stimulus to coordinate these different glaciological systems. Isotopic compositions of these precipitates record widespread subglacial groundwater connectivity beneath the LIS. Extensive basal melting and flushing of these aquifers during the last HE may have been a harbinger for terminal deglaciation.
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Affiliation(s)
- Graham H. Edwards
- Department of Earth Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Terrence Blackburn
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Gavin Piccione
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Slawek Tulaczyk
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Gifford H. Miller
- Institute of Arctic and Alpine Research and the Department of Geological Sciences, University of Colorado, Boulder, CO 80309, USA
| | - Cosmo Sikes
- Department of Geology, University of Maryland, College Park, MD 20742, USA
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9
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Dawson EJ, Schroeder DM, Chu W, Mantelli E, Seroussi H. Ice mass loss sensitivity to the Antarctic ice sheet basal thermal state. Nat Commun 2022; 13:4957. [PMID: 36104329 PMCID: PMC9474861 DOI: 10.1038/s41467-022-32632-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
Sea-level rise projections rely on accurate predictions of ice mass loss from Antarctica. Climate change promotes greater mass loss by destabilizing ice shelves and accelerating the discharge of upstream grounded ice. Mass loss is further exacerbated by mechanisms such as the Marine Ice Sheet Instability and the Marine Ice Cliff Instability. However, the effect of basal thermal state changes of grounded ice remains largely unexplored. Here, we use numerical ice sheet modeling to investigate how warmer basal temperatures could affect the Antarctic ice sheet mass balance. We find increased mass loss in response to idealized basal thawing experiments run over 100 years. Most notably, frozen-bed patches could be tenuously sustaining the current ice configuration in parts of George V, Adélie, Enderby, and Kemp Land regions of East Antarctica. With less than 5 degrees of basal warming, these frozen patches may begin to thaw, producing new loci of mass loss. This study uses ice sheet modeling experiments to show that thawing portions of the Antarctic ice sheet bed can increase century-scale mass loss, particularly in the Wilkes and Enderby Land regions of East Antarctica.
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10
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Crotti I, Quiquet A, Landais A, Stenni B, Wilson DJ, Severi M, Mulvaney R, Wilhelms F, Barbante C, Frezzotti M. Wilkes subglacial basin ice sheet response to Southern Ocean warming during late Pleistocene interglacials. Nat Commun 2022; 13:5328. [PMID: 36088458 PMCID: PMC9464198 DOI: 10.1038/s41467-022-32847-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 08/18/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractThe response of the East Antarctic Ice Sheet to past intervals of oceanic and atmospheric warming is still not well constrained but is critical for understanding both past and future sea-level change. Furthermore, the ice sheet in the Wilkes Subglacial Basin appears to have undergone thinning and ice discharge events during recent decades. Here we combine glaciological evidence on ice sheet elevation from the TALDICE ice core with offshore sedimentological records and ice sheet modelling experiments to reconstruct the ice dynamics in the Wilkes Subglacial Basin over the past 350,000 years. Our results indicate that the Wilkes Subglacial Basin experienced an extensive retreat 330,000 years ago and a more limited retreat 125,000 years ago. These changes coincide with warmer Southern Ocean temperatures and elevated global mean sea level during those interglacial periods, confirming the sensitivity of the Wilkes Subglacial Basin ice sheet to ocean warming and its potential role in sea-level change.
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11
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Stokes CR, Abram NJ, Bentley MJ, Edwards TL, England MH, Foppert A, Jamieson SSR, Jones RS, King MA, Lenaerts JTM, Medley B, Miles BWJ, Paxman GJG, Ritz C, van de Flierdt T, Whitehouse PL. Response of the East Antarctic Ice Sheet to past and future climate change. Nature 2022; 608:275-286. [PMID: 35948707 DOI: 10.1038/s41586-022-04946-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/07/2022] [Indexed: 11/09/2022]
Abstract
The East Antarctic Ice Sheet contains the vast majority of Earth's glacier ice (about 52 metres sea-level equivalent), but is often viewed as less vulnerable to global warming than the West Antarctic or Greenland ice sheets. However, some regions of the East Antarctic Ice Sheet have lost mass over recent decades, prompting the need to re-evaluate its sensitivity to climate change. Here we review the response of the East Antarctic Ice Sheet to past warm periods, synthesize current observations of change and evaluate future projections. Some marine-based catchments that underwent notable mass loss during past warm periods are losing mass at present but most projections indicate increased accumulation across the East Antarctic Ice Sheet over the twenty-first century, keeping the ice sheet broadly in balance. Beyond 2100, high-emissions scenarios generate increased ice discharge and potentially several metres of sea-level rise within just a few centuries, but substantial mass loss could be averted if the Paris Agreement to limit warming below 2 degrees Celsius is satisfied.
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Affiliation(s)
| | - Nerilie J Abram
- Research School of Earth Sciences, Australian National University, Canberra, Australian Capital Territory, Australia.,Australian Centre for Excellence in Antarctic Science, Australian National University, Canberra, Australian Capital Territory, Australia
| | | | | | - Matthew H England
- Climate Change Research Centre, University of New South Wales, Sydney, New South Wales, Australia.,Australian Centre for Excellence in Antarctic Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Annie Foppert
- Australian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Richard S Jones
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Victoria, Australia.,Securing Antarctica's Environmental Future, Monash University, Clayton, Victoria, Australia
| | - Matt A King
- School of Geography, Planning, and Spatial Sciences, University of Tasmania, Hobart, Tasmania, Australia.,Australian Centre for Excellence in Antarctic Science, University of Tasmania, Hobart, Tasmania, Australia
| | - Jan T M Lenaerts
- Department of Atmospheric and Oceanic Sciences, University of Colorado Boulder, Boulder, CO, USA
| | - Brooke Medley
- Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - Guy J G Paxman
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - Catherine Ritz
- Institut des Géosciences de l'Environnement, Université Grenoble Alpes, Grenoble, France
| | - Tina van de Flierdt
- Department of Earth Science and Engineering, Imperial College London, London, UK
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12
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Impacts of climatic changes on the worldwide potential geographical dispersal range of the leopard moth, Zeuzera pyrina (L.) (Lepidoptera: Cossidae). Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Pan L, Powell EM, Latychev K, Mitrovica JX, Creveling JR, Gomez N, Hoggard MJ, Clark PU. Rapid postglacial rebound amplifies global sea level rise following West Antarctic Ice Sheet collapse. SCIENCE ADVANCES 2021; 7:7/18/eabf7787. [PMID: 33931453 PMCID: PMC8087405 DOI: 10.1126/sciadv.abf7787] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Geodetic, seismic, and geological evidence indicates that West Antarctica is underlain by low-viscosity shallow mantle. Thus, as marine-based sectors of the West Antarctic Ice Sheet (WAIS) retreated during past interglacials, or will retreat in the future, exposed bedrock will rebound rapidly and flux meltwater out into the open ocean. Previous studies have suggested that this contribution to global mean sea level (GMSL) rise is small and occurs slowly. We challenge this notion using sea level predictions that incorporate both the outflux mechanism and complex three-dimensional viscoelastic mantle structure. In the case of the last interglacial, where the GMSL contribution from WAIS collapse is often cited as ~3 to 4 meters, the outflux mechanism contributes ~1 meter of additional GMSL change within ~1 thousand years of the collapse. Using a projection of future WAIS collapse, we also demonstrate that the outflux can substantially amplify GMSL rise estimates over the next century.
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Affiliation(s)
- Linda Pan
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA.
| | - Evelyn M Powell
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Konstantin Latychev
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
| | - Jerry X Mitrovica
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Jessica R Creveling
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Natalya Gomez
- Department of Earth and Planetary Sciences, McGill University, Montreal, Canada
| | - Mark J Hoggard
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
| | - Peter U Clark
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA
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A new sea-level record for the Neogene/Quaternary boundary reveals transition to a more stable East Antarctic Ice Sheet. Proc Natl Acad Sci U S A 2020; 117:30980-30987. [PMID: 33229561 DOI: 10.1073/pnas.2004209117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sea-level rise resulting from the instability of polar continental ice sheets represents a major socioeconomic hazard arising from anthropogenic warming, but the response of the largest component of Earth's cryosphere, the East Antarctic Ice Sheet (EAIS), to global warming is poorly understood. Here we present a detailed record of North Atlantic deep-ocean temperature, global sea-level, and ice-volume change for ∼2.75 to 2.4 Ma ago, when atmospheric partial pressure of carbon dioxide (pCO2) ranged from present-day (>400 parts per million volume, ppmv) to preindustrial (<280 ppmv) values. Our data reveal clear glacial-interglacial cycles in global ice volume and sea level largely driven by the growth and decay of ice sheets in the Northern Hemisphere. Yet, sea-level values during Marine Isotope Stage (MIS) 101 (∼2.55 Ma) also signal substantial melting of the EAIS, and peak sea levels during MIS G7 (∼2.75 Ma) and, perhaps, MIS G1 (∼2.63 Ma) are also suggestive of EAIS instability. During the succeeding glacial-interglacial cycles (MIS 100 to 95), sea levels were distinctly lower than before, strongly suggesting a link between greater stability of the EAIS and increased land-ice volumes in the Northern Hemisphere. We propose that lower sea levels driven by ice-sheet growth in the Northern Hemisphere decreased EAIS susceptibility to ocean melting. Our findings have implications for future EAIS vulnerability to a rapidly warming world.
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