Tabular calving events occur from Antarctica's large ice shelves only every few decades, and are preceded by rift propagation. We used high‐resolution imagery and ICESat‐2 data to determine the propagation rates for the three active rifts on Amery Ice Shelf (AIS; T1, T2, and E3) and observe the calving of D‐28 on September 25, 2019 along T1. AIS front advance accelerated downstream of T1 in the years before calving, possibly increasing stress at the rift tip. T1 experienced significant acceleration for 12 days before calving, coinciding with a jump in propagation of E3. ICESat‐2's high resolution and repeat acquisitions every 91 days allowed for analysis of the ice front before and after calving, and rift detection where it was not visible in imagery as a ∼1 m surface depression, suggesting that it propagates as a basal fracture. Our results show that ICESat‐2 can provide process‐scale information about iceberg calving.

中文翻译：

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带有ICESat-2和卫星图像的Amery冰架上D-28产犊事件的高分辨率三维视图

在南极洲的大型冰架上，每隔几十年就会发生一次板状产犊事件，然后是裂谷繁殖。我们使用高分辨率图像和ICESat-2数据确定了阿默里冰架上的三个活动裂谷（AIS; T1，T2和E3）的传播速率，并观察了D‐28在2019年9月25日沿T1的分娩情况。在产犊前的几年中，AIS的前部加速加速了T1的下游，可能会增加裂谷尖端的压力。T1在产犊前的12天内经历了明显的加速，这与E3的传播激增相吻合。ICESat-2的高分辨率和每91天重复采集一次，可以对产犊前后的冰锋进行分析，并进行裂谷探测，发现在图像中看不到约1 m的表面凹陷，这表明它以基底裂缝的形式传播。