Ice-shelf collapse from subsurface warming as a trigger for Heinrich events
| Type | Article | ||||||||||||
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| Date | 2011-08 | ||||||||||||
| Language | English | ||||||||||||
| Author(s) | Marcott Shaun A.1, Clark Peter U.1, Padman Laurie2, Klinkhammer Gary P.3, Springer Scott R.4, Liu Zhengyu5, 6, Otto-Bliesner Bette L.7, Carlson Anders E.5, 6, 8, Ungerer Andy3, Padman June3, He Feng5, 6, Cheng Jun9, Schmittner Andreas3 | ||||||||||||
| Affiliation(s) | 1 : Oregon State Univ, Dept Geosci, Corvallis, OR 97331 USA. 2 : Earth & Space Res, Corvallis, OR 97333 USA. 3 : Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. 4 : Earth & Space Res, Seattle, WA 98121 USA. 5 : Univ Wisconsin, Ctr Climat Res, Madison, WI 53706 USA. 6 : Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA. 7 : Natl Ctr Atmospher Res, Climate & Global Dynam Div, Boulder, CO 80307 USA. 8 : Univ Wisconsin, Dept Geosci, Madison, WI 53706 USA. 9 : Nanjing Univ Informat Sci & Technol, Key Lab Meteorol Disaster, Nanjing 210044, Peoples R China. |
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| Source | Proceedings Of The National Academy Of Sciences Of The United States Of America (0027-8424) (Natl Acad Sciences), 2011-08 , Vol. 108 , N. 33 , P. 13415-13419 | ||||||||||||
| DOI | 10.1073/pnas.1104772108 | ||||||||||||
| WOS© Times Cited | 239 | ||||||||||||
| Keyword(s) | paleoceanography, paleoclimatology, abrupt climate change | ||||||||||||
| Abstract | Episodic iceberg-discharge events from the Hudson Strait Ice Stream (HSIS) of the Laurentide Ice Sheet, referred to as Heinrich events, are commonly attributed to internal ice-sheet instabilities, but their systematic occurrence at the culmination of a large reduction in the Atlantic meridional overturning circulation (AMOC) indicates a climate control. We report Mg/Ca data on benthic foraminifera from an intermediate-depth site in the northwest Atlantic and results from a climate-model simulation that reveal basin-wide subsurface warming at the same time as large reductions in the AMOC, with temperature increasing by approximately 2 C over a 1-2 kyr interval prior to a Heinrich event. In simulations with an ocean model coupled to a thermodynamically active ice shelf, the increase in subsurface temperature increases basal melt rate under an ice shelf fronting the HSIS by a factor of approximately 6. By analogy with recent observations in Antarctica, the resulting ice-shelf loss and attendant HSIS acceleration would produce a Heinrich event. | ||||||||||||
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