Antarctic ice-shelf advance driven by anomalous atmospheric and sea-ice circulation

• Main Authors: Christie, FDW, Benham, TJ, Batchelor, CL, Rack, W, Montelli, A, Dowdeswell, JA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2022
• Subjects: Antarctica; Ice shelves; Larsen Ice Shelf; Antarctic Peninsula; sea ice; remote sensing; Sentinel; Landsat; ice-ocean-atmosphere interactions; Antarctic; Weddell; Weddell Sea; Antarc*; Ice Shelf; Ice Shelves; Sea ice
• Online Access: https://www.repository.cam.ac.uk/handle/1810/336954; https://doi.org/10.17863/CAM.84377

The disintegration of the eastern Antarctic Peninsula’s Larsen A and B ice shelves has been attributed to atmosphere and ocean warming, and increased mass-losses from the glaciers once restrained by these ice shelves have increased Antarctica’s total contribution to sea-level rise. Abrupt recessions in ice-shelf frontal position presaged the break-up of Larsen A and B, yet, in the ~20 years since these events, documented knowledge of frontal change along the entire ~1,400 km-long eastern Antarctic Peninsula is limited. Here, we show that 85% of the seaward ice-shelf perimeter fringing this coastline underwent uninterrupted advance between the early 2000s and 2019, in contrast to the two previous decades. We attribute this advance to enhanced ocean-wave dampening, ice-shelf buttressing and the absence of sea-surface slope-induced gravitational ice-shelf flow. These phenomena were, in turn, enabled by increased near-shore sea ice driven by a Weddell Sea-wide intensification of cyclonic surface winds around 2002. Collectively, our observations demonstrate that sea-ice change can either safeguard from, or set in motion, the final rifting and calving of even large Antarctic ice shelves. Flotilla Foundation and Marine Archaeology Consultants Switzerland; Prince Albert II of Monaco Foundation