DTU Space, National Space Institute, Geodynamics Department, Technical University of Denmark, Kgs. Lyngby, Denmark.
School of Earth Science, Ohio State University, Columbus, OH, USA.
Science. 2018 Jun 22;360(6395):1335-1339. doi: 10.1126/science.aao1447.
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 × 10 pascal-second) than global average, and this shortens the GIA response time scale from tens to hundreds of years. 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.
南极西部冰盖的海洋部分（WAIS）在阿蒙森海湾（ASE）中占地球海平面上升的冰冻圈贡献的四分之一，并且容易发生灾难性崩溃。对冰质量损失、冰川均衡调整（GIA）的基岩响应被认为发生在一万年的时间尺度上。我们使用新的 GPS 测量结果，该结果显示 ASE 快速（每年 41 毫米）抬升，来估计下面地幔的粘度。我们发现了比全球平均水平低得多的粘度（4×10 帕斯卡秒），这将 GIA 响应时间尺度从数十缩短到数百。我们的发现需要根据重力数据对冰质量损失进行 10%的向上修正，并增加了 WAIS 对灾难性崩溃的潜在稳定性。
