NSFGEO-NERC:A new mechanistic framework for modeling rift processes in Antarctic ice shelves validated through improved strain-rate and seismic obser

NSFGEO-NERC：通过改进的应变率和地震观测器验证南极冰架裂谷过程的新机制框架

基本信息

批准号：
NE/V013319/1
负责人：
Hilmar Gudmundsson
金额：
$ 27.54万
依托单位：
Northumbria University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FV013319%2F1
关键词：
NSFGEO NERC new mechanistic framework

项目摘要

Tabular iceberg calving accounts for a significant fraction of ice mass loss from Antarctica and is the culmination of the propagation of full-thickness fractures-known as rifts-in ice shelves. Understanding theprocesses and drivers of rifting and how best to represent rifts in large-scale ice-flow models are among thegreat challenges of modern glaciology. To date, much work has focused on developing parameterized calving laws that consider velocity, thickness, crevasse depth, and/or damage proxies at or near the calving front to represent calving (e.g., Nick et al., 2010; Duddu and Waisman, 2012; Borstad et al., 2012; Albrecht and Levermann, 2012; Bassis and Jacobs, 2013; Ultee and Bassis, 2016). Other recent work has improved ourunderstanding of the processes, drivers, and effects of rifting, often with emphasis on relating the rift path tothe stress field of the ice shelf and the mean rate of rift propagation to spatial heterogeneities in the mechanical properties of the ice (e.g., Hulbe et al., 2005; Khazendar et al., 2009; Larour et al., 2014; Borstad et al.,2017). Despite these efforts, several fundamental questions remain. What drives rift propagation? How fastdo rifts propagate and what controls the rate of propagation? How important is inelastic deformation at therift tip? Here, we propose to address each of these fundamental questions and thereby markedly contributeto our understanding of rift propagation and tabular iceberg formation in ice shelves.More specifically, we propose to test the hypotheses that large-scale rifting is driven by viscous stresseswithin the ice shelf, that rifting processes can be well-represented by linear elastic fracture mechanics, thatthe rate of rift propagation is controlled by the local geometry and mechanical properties of the ice, and thatocean induced loads (e.g., swells and tides) play an important role in rift propagation by combining remotesensing, seismic, and GPS observations with state-of-the-art ice-flow and fracture models. We propose toexploit a unique situation currently developing on Brunt Ice Shelf (BIS) and Stancomb-Wills Glacier Tongue(SWGT), Antarctica, to study the propagation of several active rift systems through remotely sensed and insitu observations and fracture modeling.

表格冰山产犊占南极冰质量损失的很大一部分，是全厚性骨折的传播的高潮，称为裂冰架。了解裂谷的过程和驱动力以及如何最好地代表大型冰流模型中的裂痕，这是现代冰川学的挑战。迄今为止，许多工作集中在开发参数化的产犊定律上，这些定律考虑了速度，厚度，裂隙深度和/或在产犊前后或附近的损坏代理以代表产犊（例如Nick等，2010; Duddu and Waisman，2012; duddu and waisman，2012; Borstad; Borstad; Borstad et el。 2016）。最近的其他工作改善了我们对裂谷的过程，驱动因素和影响的理解，通常强调关联冰架的压力场和裂谷繁殖的平均值与空间异质性的平均值，冰的机械性能（例如，Hulbe，Hulbe，Hulbe，Hulbe，2005，2005; Khazend; Khazend and and and and and and and; ael and and and and; ael and and and and and and and and and arr and and and arr. a and。 Al。，2017）。尽管做出了这些努力，但仍有几个基本问题。是什么驱动裂谷繁殖？ Fastdo裂开的繁殖和什么控制传播速率是什么？ Therift尖端的非弹性变形有多重要？在这里，我们建议解决这些基本问题中的每个问题，从而明显地理解裂谷繁殖和表格冰山的形成，尤其是，我们建议测试大规模裂变的假设，即大规模的裂缝是由粘性在冰上构成的质量质量的固定范围的稳定范围所驱动的。由冰的局部几何形状和机械性能控制，Thatocean诱导的载荷（例如，膨胀和潮汐）通过将远程启动，地震和GPS的观察与最新的冰冰球和裂纹模型相结合，在裂谷繁殖中起着重要作用。我们建议在南极洲的首发冰架（BIS）和Stancomb-Wills Wills Wills Wills Wills Wills Wills Wills Wills Wills冰川舌（SWGT）上开发出一种独特的情况，以通过远程感知和ISITU的观测和分裂建模来研究几个活跃的裂谷系统的传播。