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

• DOI: 10.1038/s43247-022-00599-z
• Publication Date: 2022-11-09T21:20:06Z
• Authors: Yusuke Suganuma; Heitaro Kaneda; Martim Mas e Braga; Takeshige Ishiwa; Takushi Koyama; Jennifer C. Newall; Jun’ichi Okuno; Takashi Obase; Fuyuki Saito; Irina Rogozhina; Jane Lund Andersen; Moto Kawamata; Motohiro Hirabayashi; Nathaniel A. Lifton; Ola Fredin; Jonathan M. Harbor; Arjen P. Stroeven; Ayako Abe-Ouchi
• Keywords: MCC; GC; QE1-996.5; 550; DAS; Geology; 15. Life on land; 551; 01 natural sciences; Environmental sciences; QE Geology; 13. Climate action; QE; GC Oceanography; Geologi; GE1-350; SDG 14 - Life Below Water; 14. Life underwater; 0105 earth and related environmental sciences

AbstractThe 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.