Bernd Etzelmüller, Henry Patton, Anders Schomacker, Justyna Czekirda, Luc Girod, Alun Hubbard, Karianne S. Lilleøren, Sebastian Westermann, Icelandic permafrost dynamics since the Last Glacial Maximum – model results and geomorphological implications, Quaternary Science Reviews, Volume 233, 2020, 106236, ISSN 0277-3791, https://doi.org/10.1016/j.quascirev.2020.106236
Icelandic permafrost dynamics since the Last Glacial Maximum : model results and geomorphological implications
|Author:||Etzelmüller, Bernd1; Patton, Henry2; Schomacker, Anders3;|
1Department of Geosciences, University of Oslo, 1047, Blindern, Oslo, Norway
2CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT the Arctic University of Norway, 9010, Tromsø, Norway
3Department of Geosciences, UiT the Arctic University of Norway, 9010, Tromsø, Norway
4Kvantum Institute, University of Oulu, 90014 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 7.5 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2020091669748
|Publish Date:|| 2020-09-16
Iceland’s periglacial realm is one of the most dynamic on the planet, with active geomorphological processes and high weathering rates of young bedrock resulting in high sediment yields and ongoing mass movement. Permafrost is discontinuous in Iceland’s highlands and mountains over c. 800 m a.s.l, and sporadic in palsa mires in the central highlands. During the late Pleistocene and Holocene, Iceland’s periglacial environment varied considerably in time and space, dominated by glacial fluctuations and periglacial processes. To evaluate the dynamics of permafrost in Iceland since the last deglaciation, we use the output of a coupled climate/ice sheet model to force a transient permafrost model (CryoGRID 2) from the Last Glacial Maximum (LGM) through to the present. We find that permafrost was widespread across the deglaciated areas of western, northern and eastern Iceland after the LGM, and that up to 20% of Iceland’s terrestrial area was underlain by permafrost throughout the late Pleistocene. This influenced geomorphological processes and landform generation: the early collapse of the marine-based ice sheet together with the aggradation of permafrost in these zones initiated the formation of abundant and now relict rock glaciers across coastal margins. Permafrost degraded rapidly after the Younger Dryas, with a marked impact on slope stability. Permafrost that formed during the Little Ice Age is again thawing rapidly, and an escalation in slope failure and mass-movement might be currently underway. Our study demonstrates that large regions of Iceland have been underlain by permafrost for millennia, facilitating landform development and influencing the stability of steep slopes.
Quaternary science reviews
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
1172 Environmental sciences
This study was financed by the Department of Geosciences, University of Oslo. HP and ALH acknowledge support by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223259. HP further acknowledges support by a grant from the Equinor-UiT Akademia agreement. An early version of the permafrost runs was implemented on the HPC at the University of Oslo by Anne Fouilloux and JC, and later followed up by LG. AH is grateful for an Academy of Finland ArcI visiting fellowship to the University of Oulu.
© 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).