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Lin Y, Hibbert FD, Whitehouse PL, Woodroffe SA, Purcell A, Shennan I, Bradley SL. A reconciled solution of Meltwater Pulse 1A sources using sea-level fingerprinting. Nat Commun 2021; 12:2015. [PMID: 33795667 PMCID: PMC8016857 DOI: 10.1038/s41467-021-21990-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 02/17/2021] [Indexed: 02/01/2023] Open
Abstract
The most rapid global sea-level rise event of the last deglaciation, Meltwater Pulse 1A (MWP-1A), occurred ∼14,650 years ago. Considerable uncertainty regarding the sources of meltwater limits understanding of the relationship between MWP-1A and the concurrent fast-changing climate. Here we present a data-driven inversion approach, using a glacio-isostatic adjustment model to invert for the sources of MWP-1A via sea-level constraints from six geographically distributed sites. The results suggest contributions from Antarctica, 1.3 m (0-5.9 m; 95% probability), Scandinavia, 4.6 m (3.2-6.4 m) and North America, 12.0 m (5.6-15.4 m), giving a global mean sea-level rise of 17.9 m (15.7-20.2 m) in 500 years. Only a North American dominant scenario successfully predicts the observed sea-level change across our six sites and an Antarctic dominant scenario is firmly refuted by Scottish isolation basin records. Our sea-level based results therefore reconcile with field-based ice-sheet reconstructions.
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Affiliation(s)
- Yucheng Lin
- Department of Geography, Durham University, Durham, UK.
- Research School of Earth Sciences, Australian National University, ACT, Canberra, Australia.
| | - Fiona D Hibbert
- Research School of Earth Sciences, Australian National University, ACT, Canberra, Australia
- Department of Environment and Geography, University of York, York, UK
| | | | | | - Anthony Purcell
- Research School of Earth Sciences, Australian National University, ACT, Canberra, Australia
| | - Ian Shennan
- Department of Geography, Durham University, Durham, UK
| | - Sarah L Bradley
- Department of Geography, The University of Sheffield, Sheffield, UK
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Ng HC, Robinson LF, McManus JF, Mohamed KJ, Jacobel AW, Ivanovic RF, Gregoire LJ, Chen T. Coherent deglacial changes in western Atlantic Ocean circulation. Nat Commun 2018; 9:2947. [PMID: 30054472 PMCID: PMC6063924 DOI: 10.1038/s41467-018-05312-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 06/28/2018] [Indexed: 11/26/2022] Open
Abstract
Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. However, the exact timing and magnitude of past AMOC shifts remain elusive, which continues to limit our understanding of the driving mechanisms of such climate variability. Here we show a consistent signal of the 231Pa/230Th proxy that reveals a spatially coherent picture of western Atlantic circulation changes over the last deglaciation, during abrupt millennial-scale climate transitions. At the onset of deglaciation, we observe an early slowdown of circulation in the western Atlantic from around 19 to 16.5 thousand years ago (ka), consistent with the timing of accelerated Eurasian ice melting. The subsequent weakened AMOC state persists for over a millennium (~16.5–15 ka), during which time there is substantial ice rafting from the Laurentide ice sheet. This timing indicates a role for melting ice in driving a two-step AMOC slowdown, with a positive feedback sustaining continued iceberg calving and climate change during Heinrich Stadial 1. The exact timing and magnitude of past changes in Atlantic Ocean circulation, and its relation to abrupt climate changes remains elusive. Here, the authors show a spatially coherent picture of western Atlantic circulation changes, which reveals a two-step AMOC slowdown at the beginning of the deglacial period.
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Affiliation(s)
- Hong Chin Ng
- School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK.
| | - Laura F Robinson
- School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK
| | - Jerry F McManus
- Department of Earth and Environmental Sciences, Columbia University and the Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA
| | - Kais J Mohamed
- Department of Marine Geosciences, University of Vigo, 36310, Vigo, Spain
| | - Allison W Jacobel
- Department of Earth and Environmental Sciences, Columbia University and the Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA
| | - Ruza F Ivanovic
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | - Lauren J Gregoire
- School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
| | - Tianyu Chen
- School of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, UK.,School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210046, China
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Menounos B, Goehring BM, Osborn G, Margold M, Ward B, Bond J, Clarke GKC, Clague JJ, Lakeman T, Koch J, Caffee MW, Gosse J, Stroeven AP, Seguinot J, Heyman J. Cordilleran Ice Sheet mass loss preceded climate reversals near the Pleistocene Termination. Science 2017; 358:781-784. [PMID: 29123066 DOI: 10.1126/science.aan3001] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 10/10/2017] [Indexed: 01/28/2023]
Abstract
The Cordilleran Ice Sheet (CIS) once covered an area comparable to that of Greenland. Previous geologic evidence and numerical models indicate that the ice sheet covered much of westernmost Canada as late as 12.5 thousand years ago (ka). New data indicate that substantial areas throughout westernmost Canada were ice free prior to 12.5 ka and some as early as 14.0 ka, with implications for climate dynamics and the timing of meltwater discharge to the Pacific and Arctic oceans. Early Bølling-Allerød warmth halved the mass of the CIS in as little as 500 years, causing 2.5 to 3.0 meters of sea-level rise. Dozens of cirque and valley glaciers, along with the southern margin of the CIS, advanced into recently deglaciated regions during the Bølling-Allerød and Younger Dryas.
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Affiliation(s)
- B Menounos
- Natural Resources and Environmental Studies Institute and Geography, University of Northern British Columbia, Prince George, British Columbia V2N 4Z9, Canada.
| | - B M Goehring
- Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA 70118, USA
| | - G Osborn
- Department of Geoscience, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - M Margold
- Geomorphology and Glaciology, Department of Physical Geography, Stockholm University, S-10691 Stockholm, Sweden
| | - B Ward
- Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - J Bond
- Yukon Geological Survey, Whitehorse, Yukon Y1A 2B5, Canada
| | - G K C Clarke
- Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - J J Clague
- Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - T Lakeman
- Geological Survey of Norway, Trondheim 7040, Norway
| | - J Koch
- Department of Geography, Kwantlen Polytechnic University, Surrey, British Columbia V3W 2M8, Canada
| | - M W Caffee
- Department of Physics and Astronomy and Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - J Gosse
- Department of Earth Sciences, Dalhousie University, Halifax Nova Scotia B3H 4R2, Canada
| | - A P Stroeven
- Geomorphology and Glaciology, Department of Physical Geography, Stockholm University, S-10691 Stockholm, Sweden.,Bolin Centre for Climate Research, Stockholm University, S-10691 Stockholm, Sweden
| | - J Seguinot
- Geomorphology and Glaciology, Department of Physical Geography, Stockholm University, S-10691 Stockholm, Sweden.,Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zürich, Zürich, Switzerland
| | - J Heyman
- Geomorphology and Glaciology, Department of Physical Geography, Stockholm University, S-10691 Stockholm, Sweden.,Department of Earth Sciences, University of Gothenburg, Sweden
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