Future sea-level rise projections carry large uncertainties, mainly driven by the unknown response of the Antarctic Ice Sheet to climate change. During the past four decades, the contribution of the East Antarctic Ice Sheet to sea-level rise has increased. However, unlike for West Antarctica, the causes of East Antarctic ice-mass loss are largely unexplored. Here, using oceanographic observations off East Antarctica (80–160° E) we show that mid-depth Circumpolar Deep Water has warmed by 0.8–2.0 °C along the continental slope between 1930–1990 and 2010–2018. Our results indicate that this warming may be implicated in East Antarctic ice-mass loss and coastal water-mass reorganization. Further, it is associated with an interdecadal, summer-focused poleward shift of the westerlies over the Southern Ocean. Since this shift is predicted to persist into the twenty-first century, the oceanic heat supply to East Antarctica may continue to intensify, threatening the ice sheet’s future stability.

未来的海平面上升预测具有很大的不确定性，主要是由于南极冰盖对气候变化的未知反应。在过去的四十年里，东南极冰盖对海平面上升的贡献有所增加。然而，与西南极洲不同的是，东南极冰块损失的原因在很大程度上尚未被探索。在这里，使用南极洲东部（80-160° E）附近的海洋观测结果，我们表明，在 1930-1990 年和 2010-2018 年间，中深度环极地深水沿大陆坡升温了 0.8-2.0°C。我们的研究结果表明，这种变暖可能与东南极冰块损失和沿海水块重组有关。此外，它与南大洋西风带以夏季为中心的年代际极移有关。