Oscillatory response of Larsen C Ice Shelf flow to the calving of iceberg A-68
Oscillatory response of Larsen C Ice Shelf flow to the calving of iceberg A-68
复制标题
拉森 C 冰架流对冰山 A-68 崩解的振荡响应
DOI：
10.1017/jog.2023.102
复制
发表时间：
2023
影响因子：
3.4
通讯作者：
Deakin K
中科院分区：
文献类型：
--
作者：
Deakin K
自世纪末以来，南极半岛的几个冰架的崩溃导致了多个以前支持出口冰川的上游加速，引发了对南极洲剩余冰架稳定性及其消亡可能对内陆冰的影响的质疑。在这里，我们使用高时间分辨率Sentinel-1A/B合成孔径雷达衍生观测来评估Larsen C冰架（LCIS）对2017年巨型冰山A-68产犊的速度响应。我们发现，在A-68产犊后的几个月里，穿越LCIS的冰架流量出现了明显的振荡，从平均11.3 m yr − 1的近冰架宽度的减速开始。虽然下降接近可探测性的极限，这些冰流的变化似乎已经预示着类似的振荡在几年前A-68的分离，主要与重大裂谷事件，一起反映了潜在的迄今未观察到的冰架机械过程与冰架弱化的重要影响。然而，这种冰流振荡是短暂的，最近的观测表明，冰流的速度低于长期冰流速度。总的来说，我们的观测揭示了复杂的时空模式的冰流变化在LCIS。类似的突然波动可能对其他冰架的稳定性产生重要影响，因此今后有必要继续密切观察南极洲的海岸线。
The collapse of several ice shelves in the Antarctic Peninsula since the late 20th century has resulted in the upstream acceleration of multiple formerly buttressed outlet glaciers, raising questions about the stability of Antarctica's remaining ice shelves and the effects their demise may have upon inland ice. Here, we use high temporal resolution Sentinel-1A/B synthetic aperture radar-derived observations to assess the velocity response of Larsen C Ice Shelf (LCIS) to the calving of colossal iceberg A-68 in 2017. We find marked oscillations in ice-shelf flow across LCIS in the months following A-68's calving, beginning with a near-ice-shelf-wide slowdown of 11.3 m yr−1 on average. While falling close to the limits of detectability, these ice-flow variations appear to have been presaged by similar oscillations in the years prior to A-68's breakaway, associated primarily with major rifting events, together reflecting potentially hitherto unobserved ice-shelf mechanical processes with important implications for ice-shelf weakening. Such ice-flow oscillations were, however, short-lived, with more recent observations suggesting a deceleration below longer-term rates of ice flow. Collectively, our observations reveal complex spatial-temporal patterns of ice-flow variability at LCIS. Similarly abrupt fluctuations may have important implications for the stability of other ice shelves, necessitating the continued, close observation of Antarctica's coastline in the future.