Ice-Shelf Rift Propagation: Computational Simulation Using a Fracture Fracture Mechanics Approach

冰架裂谷传播：使用断裂力学方法进行计算模拟

• 批准号: 0125754
• 负责人: Christina Hulbe
• 金额: $ 28.26万
• 依托单位: Portland State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125754&HistoricalAwards=false
• 关键词: Ice; Shelf; Rift; Propagation; Computational

This award supports a project to develop computational models to simulate ice-shelf rift propagation using a combination of well-established ice-shelf creep-flow models and new crevasse models, based on linear elastic fracture mechanics (LEFM). The overall objective of the proposed work is to simulate rift propagation and eventual large iceberg calving,and place those processes within a larger ice sheet and climate context. The work will proceed in stages, first developing models of single-and multiple-crevasse propagation; then using those models to evaluate propagation sensitivity to various environmental conditions; and third developing models that incorporate both crevasse propagation and advection within an ice- shelf system. Model development will be guided by and evaluated according to satellite observations of rift propagation in several characteristic locations on Antarctic ice shelves. New numerical models of fracture in ice will have applications to many problems in glaciology. The research proposed here is directed toward large rift formation in ice shelves and subsequent iceberg calving. It is motivated by the need to understand observed changes in modern ice shelves,and their connection to climate. Where it has been sampled, the sedimentary record of the Weddell Sea sector implies Peninsular ice shelf variability on millennial time scales. The ability to simulate iceberg calving in a credible way will improve our ability to reproduce such events and place the complete cycle of ice shelf advance and retreat in an ice-dynamics context. That will, in turn, enable us to place ice-shelf cycles within the climate cycles that ultimately drive ice-sheet mass balance.

该奖项支持一个项目，开发计算模型，模拟冰架裂缝传播使用完善的冰架蠕变流动模型和新的决口模型的组合，基于线弹性断裂力学（LEFM）。 拟议工作的总体目标是模拟裂缝传播和最终的大型冰山崩解，并将这些过程置于更大的冰盖和气候背景下。 这项工作将分阶段进行，首先开发单裂隙和多裂隙传播模型;然后使用这些模型评估传播对各种环境条件的敏感性;第三，开发将裂隙传播和平流纳入冰架系统的模型。 将根据对南极冰架若干特征地点裂缝扩展情况的卫星观测来指导和评价模型的发展。 新的冰破裂数值模型将应用于冰川学的许多问题。 这里提出的研究旨在研究冰架中大裂缝的形成以及随后的冰山崩解。 它的动机是需要了解观测到的现代冰架变化及其与气候的联系。 在取样的地方，威德尔海部分的沉积记录意味着半岛冰架在千年时间尺度上的变化。 以可信的方式模拟冰山崩解的能力将提高我们再现此类事件的能力，并将冰架进退的完整周期置于冰动力学背景下。 反过来，这将使我们能够将冰架周期置于最终推动冰盖质量平衡的气候周期之内。