Antarctic cold relapse

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Global temperature change between 18,000 and 8,000 BC Based on data from EPICA - Dome C in East Antarctica
the black curve results from the proxy data from EPICA Dome C ( online ) for the last 40,000 years (today is on the left)
compare the yellow curve for the last 140,000 years (today is on the left); This cold relapse did not occur before the Eem warm period

The Antarctic cold relapse , abbreviated ACR (for English. Antarctic Cold Reversal ), was a section in the Earth's history, at the end of the last in the ice age took place a global cooling after thousands of years of warming and global glacier melt before about 14,500 years ago.

The last ice age maximum and sea level minimum occurred 21,000 years BP . After 18,000 BP, Antarctic ice cores show gradual warming. Around 14,700 BP there was a large meltwater pulse that came from either the Antarctic Ice Sheet or the Laurentide Ice Sheet and is called meltwater pulse 1A . This pulse of meltwater caused the sea ​​level to rise , raising the global sea level by 20 meters within two centuries. It is believed that this influenced the beginning of the Bölling and Alleröd interstadials , which were major disruptions in the ice age cold in the northern hemisphere. In addition, the meltwater pulse 1A in the Antarctic and the southern hemisphere was accompanied by a renewed cooling phase, the Antarctic cold relapse , which started around 14,500 BP and lasted two thousand years; it is an example of warming that resulted in cooling. Something similar was observed with the misox fluctuation . The Antarctic cold relapse brought a mean cooling of about 3 ° C. The Younger Dryas began during the Antarctic Cold Relapse, which ended in the middle of the Younger Dryas.

This pattern of decoupling between the northern and southern hemisphere or "south leads, north lags behind" ( southern lead, northern lag ) manifested itself in subsequent climatic events. The explanation of this decoupling of the earth's hemispheres and the mechanisms of the warming and cooling trend are the subject of studies and discussions in climate research. The specific times and extent of the Antarctic cold relapse are also the subject of this debate.

Compared to the beginning of the Antarctic Cold Relapse, the Oceanic Cold Relapse in the Southern Ocean began with a delay of about 800 years.

Individual evidence

  1. ↑ Frank Oldfield; P. 97; see pp. 98-107
  2. ↑ Thomas Blunier et al .: Phase Lag of Antarctic and Greenland Temperature in the load Glacial ... . In: Reconstructing Ocean History: A Window into the Future , pp. 121-138

swell

  • Fatima Abrantes and Alan C. Mix (Eds.): Reconstructing Ocean History: A Window into the Future . Kluwer Academic, New York 1999, ISBN 0-306-46293-1 .
  • TJ Blunier et al .: Timing of the Antarctic Cold Reversal and the atmospheric CO 2 increase with respect to the Younger Dryas event . In: Geophysical Research Letters . tape 24 , no. 21 , 1997, pp. 2683-2686 , doi : 10.1029 / 97GL02658 .
  • Thomas M. Cronin: Principles of Paleoclimatology . Columbia University Press, New York 1999, ISBN 0-231-10954-7 .
  • Jürgen Ehlers and Philip Leonard Gibbard: Quaternary Glaciations: Extent and Chronology. Part III: South America, Asia, Africa, Australasia, Antarctica . Elsevier, Amsterdam 2004, ISBN 0-444-51593-3 .
  • Vera Markgraf (Ed.): Interhemispheric Climate Linkages . Elsevier, Amsterdam 2001, ISBN 0-12-472670-4 .
  • Frank Oldfield: Environmental Change: Key Issues and Alternative Perspectives . Cambridge University Press, Cambridge 2005, ISBN 0-521-82936-4 .