The Importance of Icelandic Ice Sheet Growth and Retreat on Mantle CO 2 Flux

• Published in: Geophysical Research Letters
• Main Authors: Armitage, John J., Ferguson, David J., Petersen, Kenni D., Creyts, Timothy T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2019
• Subjects: Ice Sheet; Iceland
• Online Access: https://pure.au.dk/portal/en/publications/87a496a3-31da-4ff2-aa32-ca5d0e855706; https://doi.org/10.1029/2019GL081955; https://pure.au.dk/ws/files/196910267/The_importance_of_Icelandic_ice_sheet_growth_and_retreat_on_mantle_CO2_flux.pdf; http://www.scopus.com/inward/record.url?scp=85068113542&partnerID=8YFLogxK

Climate cycles may significantly affect the eruptive behavior of terrestrial volcanoes due to pressure changes caused by glacial loading, which raises the possibility that climate change may modulate CO 2 degassing via volcanism. In Iceland, magmatism is likely to have been influenced by glacial activity. To explore if deglaciation therefore impacted CO 2 flux, we coupled a model of glacial loading over the last ∼120 ka to melt generation and transport. We find that a nuanced relationship exists between magmatism and glacial activity. Enhanced CO 2 degassing happened prior to the main phase of late-Pleistocene deglaciation, and it is sensitive to the duration of the growth of the ice sheet entering into the Last Glacial Maximum (LGM), as well as the rate of ice loss. Ice sheet growth depresses melting in the upper mantle, creating a delayed pulse of CO 2 out-gassing, as the magmatic system recovers from the effects of loading.