The Antarctic Ice Sheet loses mass via its ice shelves predominantly through two processes: basal melting and iceberg calving. Iceberg calving is episodic and infrequent, and not well parameterized in ice-sheet models. Here, we investigate the impact of hydrostatic forces on calving. We develop two-dimensional elastic and viscous numerical frameworks to model the ‘footloose’ calving mechanism. This mechanism is triggered by submerged ice protrusions at the ice front, which induce unbalanced buoyancy forces that can lead to fracturing. We compare the results to identify the different roles that viscous and elastic deformations play in setting the rate and magnitude of calving events. Our results show that, although the bending stresses in both frameworks share some characteristics, their differences have important implications for modeling the calving process. In particular, the elastic model predicts that maximum stresses arise farther from the ice front than in the viscous model, leading to larger calving events. We also find that the elastic model would likely lead to more frequent events than the viscous one. Our work provides a theoretical framework for the development of a better understanding of the physical processes that govern glacier and ice-shelf calving cycles.

中文翻译：

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粘性和弹性浮力应力是冰架崩解的驱动因素

南极冰盖主要通过两个过程通过其冰架失去质量：基础融化和冰山崩解。冰山崩解是偶发的且不频繁的，并且在冰盖模型中没有很好地参数化。在这里，我们研究流体静力对产犊的影响。我们开发了二维弹性和粘性数值框架来模拟“自由”产犊机制。这种机制是由冰锋处的水下冰突出物触发的，这些突出物会引起不平衡的浮力，从而导致压裂。我们比较结果以确定粘性和弹性变形在设定产犊事件的速率和幅度中所起的不同作用。我们的结果表明，尽管两种框架中的弯曲应力具有一些共同特征，它们的差异对产犊过程的建模具有重要意义。特别是，弹性模型预测最大应力比粘性模型更远离冰锋，从而导致更大的产犊事件。我们还发现弹性模型可能会导致比粘性模型更频繁的事件。我们的工作为更好地理解控制冰川和冰架崩解周期的物理过程提供了一个理论框架。