The weakening and/or removal of floating ice shelves in Antarctica can induce inland ice flow acceleration. Numerical modelling suggests these processes will play an important role in Antarctica's future sea-level contribution, but our understanding of the mechanisms that lead to ice tongue/shelf collapse is incomplete and largely based on observations from the Antarctic Peninsula and West Antarctica. Here, we use remote sensing of structural glaciology and ice velocity from 2001 to 2020 and analyse potential ocean-climate forcings to identify mechanisms that triggered the rapid disintegration of ~2445 km2 of ice mélange and part of the Voyeykov Ice Shelf in Wilkes Land, East Antarctica between 27 March and 28 May 2007. Results show disaggregation was pre-conditioned by weakening of the ice tongue's structural integrity and was triggered by mélange removal driven by a regional atmospheric circulation anomaly and a less extensive latent-heat polynya. Disaggregation did not induce inland ice flow acceleration, but our observations highlight an important mechanism through which floating termini can be removed, whereby the break-out of mélange and multiyear landfast sea ice triggers disaggregation of a structurally-weak ice shelf. These observations highlight the need for numerical ice-sheet models to account for interactions between sea-ice, mélange and ice shelves.

中文翻译：

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Voyeykov Ice Shelf (2007)，Wilkes Land，East Antarctica 解体的触发因素及其后续演变

南极洲浮冰架的减弱和/或去除会导致内陆冰流加速。数值模型表明，这些过程将在南极洲未来的海平面贡献中发挥重要作用，但我们对导致冰舌/冰架坍塌机制的理解不完整，主要基于南极半岛和南极洲西部的观测。在这里，我们使用 2001 年至 2020 年的结构冰川学和冰速遥感，并分析潜在的海洋气候强迫，以确定引发约 2445 公里快速解体的机制22007 年 3 月 27 日至 5 月 28 日期间，南极洲东部威尔克斯地的冰混合和 Voyeykov 冰架的一部分。结果表明，分解是由于冰舌结构完整性的减弱而预先调节的，并且是由区域大气驱动的混合去除引发的循环异常和较不广泛的潜热寒冬。分解并没有导致内陆冰流加速，但我们的观察强调了一个重要的机制，通过该机制可以去除浮动终端，即混合冰和多年陆地海冰的破裂引发结构薄弱的冰架的分解。这些观察结果突出表明需要数字冰盖模型来解释海冰、混合冰架和冰架之间的相互作用。