Persistent millennial-scale glacier fluctuations in Ireland between 24 ka and 10 ka

Aaron M Barth, Peter U Clark, Jorie Clark, Gerard H Roe, Shaun A Marcott, AM McCabe, Marc W Caffee, Joshua K Cuzzone, P. Dunlop

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7 Citations (Scopus)

Abstract

We report 80 10Be ages on 14 moraines from Irish cirques that show a previously unrecognized signal of at least eight millennial-scale fluctuations between 24.5±0.7 ka and 11.0±0.3 ka. Several moraine ages may be correlative with abrupt warming at the onset of the Bølling (14.7 ka) and the end of the Younger Dryas (11.7 ka), suggesting a forced response. Our ages also identify glacier fluctuations that occurred when regional temperatures were relatively stable. This finding is consistent with modeling results showing several hundred-meter-scale glacier fluctuations in response to interannual variability. At the same time, our composite record of cirque-glacier average equilibrium line altitudes (ELAs) shows a response to warming due to increasing greenhouse gases and summer insolation modulated by abrupt climate changes. Our new 10Be chronology thus records both forced and unforced millennial-scale glacier fluctuations superimposed on a lower frequency ELA signal of forced response to climate change.
Original languageEnglish
Pages (from-to)151-154
Number of pages4
JournalGeology
Volume46
Issue number2
Early online date12 Dec 2017
DOIs
Publication statusPublished - 28 Feb 2018

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Keywords

  • Glacier
  • Cirque
  • Glaciation
  • Ice Sheet

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