Regional sea-level highstand triggered Holocene ice sheet thinning across coastal Dronning Maud Land, East Antarctica

• Published in: Communications Earth & Environment
• Main Authors: Suganuma, Yusuke, Kaneda, Heitaro, Mas e Braga, Martim, Ishiwa, Takeshige, Koyama, Takushi, Newall, Jennifer, Okuno, Jun'ichi, Obase, Takashi, Saito, Fuyuki, Rogozhina, Irina, Andersen, Jane, Kawamata, Moto, Hirabayashi, Motohiro, Lifton, Nathaniel, Fredin, Ola, Harbor, Jonathan, Stroeven, Arjen, Abe-Ouchi, Ayako
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Antarctic; Dronning Maud Land; East Antarctic Ice Sheet; East Antarctica; Antarc*; Antarctica; Ice Sheet; Ice Shelf
• Online Access: https://research-portal.st-andrews.ac.uk/en/publications/5994b39e-ed8c-4a69-9a55-6cb993dbc77a; https://doi.org/10.1038/s43247-022-00599-z; https://research-repository.st-andrews.ac.uk/bitstream/10023/27494/1/Suganuma_2022_CEE_RegionalSea_level_CC.pdf

The East Antarctic Ice Sheet stores a vast amount of freshwater, which makes it the single largest potential contributor to future sea-level rise. However, the lack of well-constrained geological records of past ice sheet changes impedes model validation, hampers mass balance estimates, and inhibits examination of ice loss mechanisms. Here we identify rapid ice-sheet thinning in coastal Dronning Maud Land from Early to Middle Holocene (9000–5000 years ago) using a deglacial chronology based on in situ cosmogenic nuclide surface exposure dates from central Dronning Maud Land, in concert with numerical simulations of regional and continental ice-sheet evolution. Regional sea-level changes reproduced from our refined ice-load history show a highstand at 9000–8000 years ago. We propose that sea-level rise and a concomitant influx of warmer Circumpolar Deep Water triggered ice shelf breakup via the marine ice sheet instability mechanism, which led to rapid thinning of upstream coastal ice sheet sectors.