A quick rebound for Antarctic crust Earth's crust deforms under the load of glaciers and ice sheets. When these masses are removed, the crust rebounds at a time scale determined by the viscosity of the upper mantle. Using GPS, Barletta et al. found that the viscosity of the mantle under the West Antarctic Ice Sheet is much lower than expected. This means that as ice is lost, the crust rebounds much faster than previously expected. Although estimates of total ice loss have to be revised upward, the surprising finding indicates that the ice sheet may stabilize against catastrophic collapse. Science, this issue p. 1335 A new viscosity model requires a much lower viscosity under the Amundsen Sea Embayment, stabilizing the Antarctic Ice Sheet. The marine portion of the West Antarctic Ice Sheet (WAIS) in the Amundsen Sea Embayment (ASE) accounts for one-fourth of the cryospheric contribution to global sea-level rise and is vulnerable to catastrophic collapse. The bedrock response to ice mass loss, glacial isostatic adjustment (GIA), was thought to occur on a time scale of 10,000 years. We used new GPS measurements, which show a rapid (41 millimeters per year) uplift of the ASE, to estimate the viscosity of the mantle underneath. We found a much lower viscosity (4 × 1018 pascal-second) than global average, and this shortens the GIA response time scale to decades up to a century. Our finding requires an upward revision of ice mass loss from gravity data of 10% and increases the potential stability of the WAIS against catastrophic collapse.

中文翻译：

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在阿蒙森海湾观察到的快速基岩隆起促进了冰盖的稳定性

南极地壳的快速回弹 地壳在冰川和冰盖的负载下变形。当这些物质被移除时，地壳会在由上地幔的粘度决定的时间尺度上反弹。使用 GPS，Barletta 等人。发现西南极冰盖下地幔的粘度远低于预期。这意味着随着冰的消失，地壳的反弹速度比之前预期的要快得多。尽管总冰损失的估计必须向上修正，但令人惊讶的发现表明冰盖可能会稳定下来，以免发生灾难性的坍塌。科学，这个问题 p。1335 新的粘度模型要求阿蒙森海海湾下的粘度低得多，从而稳定南极冰盖。阿蒙森海海湾 (ASE) 中南极西部冰盖 (WAIS) 的海洋部分占全球海平面上升冰冻圈贡献的四分之一，并且容易遭受灾难性崩塌。对冰质量损失的基岩响应，即冰川均衡调整 (GIA)，被认为发生在 10,000 年的时间尺度上。我们使用了新的 GPS 测量结果，显示 ASE 快速（每年 41 毫米）抬升，以估计下方地幔的粘度。我们发现粘度比全球平均水平低得多（4 × 1018 帕斯卡-秒），这将 GIA 响应时间缩短到几十到一个世纪。我们的发现需要将重力数据中的冰质量损失向上修正 10%，并增加 WAIS 抵御灾难性坍塌的潜在稳定性。