Image of core, with a coarser layer in the middle

Jonathan Warnock and colleagues published a new understanding of Antarctic Ice Sheet history and behavior using results from International Ocean Discovery Program Expedition 382. The paper, titled "Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments," examined the sedimentary characteristics of distinct layers within core samples retrieved from the seafloor in a region known as Iceberg Alley near Antarctica. 

Using sediment characteristics, the team found that the Antarctic Ice Sheet lost and gained ice more frequently in the geologic past than in more recent times. Previous to 1.2 million years ago, Antarctica’s ice fluctuated often, with approximately 41,000-year frequency, releasing icebergs that carried sediment analyzed in this paper. More recently, Antarctica’s ice mass has been more stable, changing size with a 100,000-year frequency. The paper highlights the ability of Antarctica to lose ice mass rapidly.

Full Reference

Bailey, Ian, Sidney Hemming, Brendan T. Reilly, Gavyn Rollinson, Trevor Williams, Michael E. Weber, Maureen E. Raymo et al. "Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments." Paleoceanography and paleoclimatology 37, no. 7 (2022): e2022PA004433.