Donda Federica, Rebesco Michele, Kovacevic Vedrana, Silvano Alessandro, Bensi Manuel, De Santis Laura, Rosenthal Yair, Torricella Fiorenza, Baradello Luca, Gei Davide, Leventer Amy, Post Alix, Leitchenkov German, Noble Taryn, Zgur Fabrizio, Cova Andrea, O'Brien Philip, Romeo Roberto
National Institute of Oceanography and Applied Geophysics-OGS, Borgo Grotta Gigante 42/c, 34010, Sgonico, Trieste, Italy.
School of Ocean and Earth Science, University of Southampton, University Road, Southampton, SO17 1BJ, UK.
Nat Commun. 2024 Jul 17;15(1):6028. doi: 10.1038/s41467-024-50160-z.
The intrusion of relatively warm water onto the continental shelf is widely recognized as a threat to Antarctic ice shelves and glaciers grounded below sea level, as enhanced ocean heat increases their basal melt. While the circulation of warm water has been documented on the East Antarctic continental shelf, the modes of warm water transport from the deep ocean onto the shelf are still uncertain. This makes predicting the future responses of major East Antarctic marine-grounded glaciers, such as Totten and Ninnis glaciers, particularly challenging. Here, we outline the key role of submarine canyons to convey southward flowing currents that transport warm Circumpolar Deep Water toward the East Antarctic shelf break, thus facilitating warm water intrusion on the continental shelf. Sediment drifts on the eastern flank of the canyons provide evidence for sustained southward-directed flows. These morpho-sedimentary features thus highlight areas potentially prone to enhanced ocean heat transport toward the continental shelf, with repercussions for past, present, and future glacial melting and consequent sea level rise.
相对温暖的海水侵入大陆架被广泛认为是对海平面以下的南极冰架和冰川的一种威胁，因为海洋热量增加会导致它们的底部融化加剧。虽然在东南极大陆架上已经记录到了暖水环流，但从深海向大陆架输送暖水的方式仍然不确定。这使得预测东南极主要海洋型冰川（如托滕冰川和尼尼斯冰川）未来的响应变得特别具有挑战性。在这里，我们概述了海底峡谷在输送向南流动的洋流方面的关键作用，这些洋流将温暖的环极深层水输送到东南极大陆架边缘，从而促进暖水侵入大陆架。峡谷东侧的沉积物漂移为持续的南向水流提供了证据。因此，这些地貌沉积特征突出了可能易于增强向大陆架的海洋热量输送的区域，这对过去、现在和未来的冰川融化以及随之而来的海平面上升都有影响。
