EGU22-4293, updated on 27 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Permafrost Evolution on the British Isles during the Last Deglaciation.

Paul Toechterle1, R. Lawrence Edwards2, John Gunn3, Tim Atkinson4, Julian B. Murton5, Marc Luetscher6, and Gina E. Moseley1
Paul Toechterle et al.
  • 1Univ. Innsbruck, Inst. Geologie, Innsbruck, Austria (
  • 2Dept. Earth Sciences, University of Minnesota, Minneapolis, USA
  • 3School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
  • 4Dept. Earth Sciences, University College London, London, UK
  • 5Dept. Geography, University of Sussex, Brighton, UK
  • 6Swiss Inst. for Speleology and Karst Studies (SISKA), La Chaux-de-Fonds, Switzerland

Globally, near-surface permafrost is likely to warm, thin or disappear in many areas subject to future climate warming and wetting, creating a positive atmospheric feedback where the permafrost is rich in carbon. Unfortunately, substantial uncertainty exists as to the extent and timing of thawing in response to atmospheric forcing. Cryogenic cave carbonates (CCCs),  a recently described type of speleothem, precipitate when cave ice forms and thus provide opportunities to constrain periods when permafrost was present at a given cave site. Here, we present a unique dataset comprising 38 230Th/U ages of CCCs from two caves in the Mendips, southwest England (51°N), and two caves in the Peak District, central England (53°N), all of which are currently ice-free. Whilst many ages are clean, reliable and high precision, the accuracy of those containing initial 230This improved greatly by constructing isochrons and applying further statistical methods.

The ages of CCCs reveal two distinct periods of isothermal permafrost conditions, peaking during i) the early Bølling–Allerød interstadial at approximately 14,463 ± 145 yBP* and ii) the late Younger Dryas around 11,719 ± 229 yBP. Such isothermal conditions (i.e., where values of mean annual ground temperature are commonly a fraction of a degree below 0°C and exist through much of the depth profile of permafrost) are thought to represent the later stages of permafrost warming prior to its disappearance. We attribute this isothermal, disequilibrium permafrost evolution during the last deglaciation of the British–Irish Ice Sheet to climatic variations linked to North Atlantic sea-ice extent and seasonality.

*years before 1950

How to cite: Toechterle, P., Edwards, R. L., Gunn, J., Atkinson, T., Murton, J. B., Luetscher, M., and Moseley, G. E.: Permafrost Evolution on the British Isles during the Last Deglaciation., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4293,, 2022.


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