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

• Published in: Geophysical Research Letters
• Main Authors: Armitage, John, Ferguson, David, Petersen, Kenni, Creyts, Timothy
• Other Authors: Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), School of Earth and Environment Leeds (SEE), University of Leeds, Aarhus University Aarhus, Lamont-Doherty Earth Observatory (LDEO), Columbia University New York, French National Research Agency (ANR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: VELOCITY; EMISSIONS; INVERSION; CALIFORNIA; THOLEIITES; SENSITIVITY; DEGLACIATION; RIDGE; VOLCANISM; SEA-LEVEL; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; Ice Sheet; Iceland
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-02919791; https://hal-insu.archives-ouvertes.fr/insu-02919791/document; https://hal-insu.archives-ouvertes.fr/insu-02919791/file/Armitage_et_al-2019-Geophysical_Research_Letters.pdf; https://doi.org/10.1029/2019GL081955

International audience 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 CO2 degassing via volcanism. In Iceland, magmatism is likely to have been influenced by glacial activity. To explore if deglaciation therefore impacted CO2 flux, we coupled a model of glacial loading over the last similar to 120 ka to melt generation and transport. We find that a nuanced relationship exists between magmatism and glacial activity. Enhanced CO2 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 CO2 out-gassing, as the magmatic system recovers from the effects of loading.