NSF-NERC: Thwaites Interdisciplinary Margin Evolution (TIME): The Role of Shear Margin Dynamics in the Future Evolution of the Thwaites Drainage Basin

NSF-NERC：思韦茨跨学科边缘演化（TIME）：剪切边缘动力学在思韦茨流域未来演化中的作用

• 批准号: 1739027
• 负责人: Slawek Tulaczyk
• 金额: $ 236.87万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1739027&HistoricalAwards=false
• 关键词: NSF; NERC; Thwaites; Interdisciplinary; Margin

This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Collapse of the West Antarctic Ice Sheet (WAIS) could raise the global sea level by about 5 meters (16 feet) and the scientific community considers it the most significant risk for coastal environments and cities. The risk arises from the deep, marine setting of WAIS. Although scientists have been aware of the precarious setting of this ice sheet since the early 1970s, it is only now that the flow of ice in several large drainage basins is undergoing dynamic change consistent with a potentially irreversible disintegration. Understanding WAIS stability and enabling more accurate prediction of sea-level rise through computer simulation are two of the key objectives facing the polar science community today. This project will directly address both objectives by: (1) using state-of-the-art technologies to observe rapidly deforming parts of Thwaites Glacier that may have significant control over the future evolution of WAIS, and (2) using these new observations to improve ice-sheet models used to predict future sea-level rise. This project brings together a multidisciplinary team of UK and US scientists. This international collaboration will result in new understanding of natural processes that may lead to the collapse of the WAIS and will boost infrastructure for research and education by creating a multidisciplinary network of scientists. This team will mentor three postdoctoral researchers, train four Ph.D. students and integrate undergraduate students in this research project.The project will test the overarching hypothesis that shear-margin dynamics may exert powerful control on the future evolution of ice flow in Thwaites Drainage Basin. To test the hypothesis, the team will set up an ice observatory at two sites on the eastern shear margin of Thwaites Glacier. The team argues that weak topographic control makes this shear margin susceptible to outward migration and, possibly, sudden jumps in response to the drawdown of inland ice when the grounding line of Thwaites retreats. The ice observatory is designed to produce new and comprehensive constraints on englacial properties, including ice deformation rates, ice crystal fabric, ice viscosity, ice temperature, ice water content and basal melt rates. The ice observatory will also establish basal conditions, including thickness and porosity of the till layer and the deeper marine sediments, if any. Furthermore, the team will develop new knowledge with an emphasis on physical processes, including direct assessment of the spatial and temporal scales on which these processes operate. Seismic surveys will be carried out in 2D and 3D using wireless geophones. A network of broadband seismometers will identify icequakes produced by crevassing and basal sliding. Autonomous radar systems with phased arrays will produce sequential images of rapidly deforming internal layers in 3D while potentially also revealing the geometry of a basal water system. Datasets will be incorporated into numerical models developed on different spatial scales. One will focus specifically on shear-margin dynamics, the other on how shear-margin dynamics can influence ice flow in the whole drainage basin. Upon completion, the project aims to have confirmed whether the eastern shear margin of Thwaites Glacier can migrate rapidly, as hypothesized, and if so what the impacts will be in terms of sea-level rise in this century and beyond.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目为美国国家科学基金会 (NSF) 和英国自然环境研究委员会 (NERC) 发起的联合倡议做出了贡献，该倡议旨在大幅改进对源自西部思韦茨冰川的冰损失和海平面上升的十年和长期预测南极洲。 南极西部冰盖 (WAIS) 的崩塌可能会使全球海平面上升约 5 米（16 英尺），科学界认为这是对沿海环境和城市最重大的风险。风险源自 WAIS 的深层海洋环境。尽管自 20 世纪 70 年代初以来，科学家们就已经意识到该冰盖的危险状况，但直到现在，几个大型流域盆地中的冰流才开始发生动态变化，并可能发生不可逆转的崩解。了解 WAIS 稳定性并通过计算机模拟更准确地预测海平面上升是极地科学界当今面临的两个关键目标。该项目将通过以下方式直接实现这两个目标：（1）使用最先进的技术来观测思韦茨冰川的快速变形部分，这些部分可能对 WAIS 的未来演变具有重要控制作用，以及（2）利用这些新的观测结果改进用于预测未来海平面上升的冰盖模型。该项目汇集了英国和美国科学家的多学科团队。这项国际合作将带来对可能导致 WAIS 崩溃的自然过程的新认识，并将通过创建多学科科学家网络来加强研究和教育基础设施。该团队将指导三名博士后研究人员，培养四名博士。该项目将测试一个总体假设，即剪切裕度动力学可能对思韦茨流域冰流的未来演化发挥强大的控制作用。为了验证这一假设，研究小组将在思韦茨冰川东部剪切边缘的两个地点建立一个冰观测站。研究小组认为，薄弱的地形控制使得剪切裕度容易向外迁移，并且当思韦茨的接地线后退时，可能会因内陆冰层的消退而突然跳跃。冰观测站旨在对冰川特性产生新的综合约束，包括冰变形率、冰晶结构、冰粘度、冰温度、冰水含量和基础融化速率。冰观测站还将确定基础条件，包括耕层和更深海洋沉积物（如果有）的厚度和孔隙度。此外，该团队将开发新的知识，重点是物理过程，包括直接评估这些过程运行的空间和时间尺度。将使用无线地震检波器以 2D 和 3D 方式进行地震勘探。宽带地震仪网络将识别由裂缝和基底滑动产生的冰震。具有相控阵的自主雷达系统将生成快速变形内层的 3D 连续图像，同时还可能揭示基础水系统的几何形状。数据集将被纳入在不同空间尺度上开发的数值模型中。一个将专门关注剪切边际动力学，另一个关注剪切边际动力学如何影响整个流域的冰流。项目完成后，旨在确认思韦茨冰川东部剪切边缘是否能够像假设的那样快速迁移，如果是的话，将对本世纪及以后的海平面上升产生什么影响。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Modelling thermomechanical ice deformation using an implicit pseudo-transient method (FastICE v1.0) based on graphical processing units (GPUs)

使用基于图形处理单元 (GPU) 的隐式伪瞬态方法 (FastICE v1.0) 对热机械冰变形进行建模

• DOI: 10.5194/gmd-13-955-2020
• 发表时间: 2020
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: Räss, Ludovic;Licul, Aleksandar;Herman, Frédéric;Podladchikov, Yury Y.;Suckale, Jenny
• 通讯作者: Suckale, Jenny

Ambient high-frequency seismic surface waves in the firn column of central west Antarctica

南极洲中西部冷杉柱中的环境高频地震面波

• DOI: 10.1017/jog.2021.135
• 发表时间: 2022
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: Chaput, Julien;Aster, Rick;Karplus, Marianne;Nakata, Nori
• 通讯作者: Nakata, Nori

When floods hit the road: Resilience to flood-related traffic disruption in the San Francisco Bay Area and beyond

• DOI: 10.1126/sciadv.aba2423
• 发表时间: 2020-08-01
• 期刊: SCIENCE ADVANCES
• 影响因子: 13.6
• 作者: Kasmalkar, Indraneel G.;Serafin, Katherine A.;Suckale, Jenny
• 通讯作者: Suckale, Jenny

Rapid and accurate polarimetric radar measurements of ice crystal fabric orientation at the Western Antarctic Ice Sheet (WAIS) Divide ice core site

• DOI: 10.5194/tc-15-4117-2021
• 发表时间: 2021-08
• 期刊: The Cryosphere
• 作者: T. J. Young;C. Martín;P. Christoffersen;D. Schroeder;S. Tulaczyk;E. Dawson

Traffic accidents and delays present contrasting pictures of traffic resilience to coastal flooding in the San Francisco Bay Area, USA

• DOI: 10.1016/j.uclim.2021.100851
• 发表时间: 2021-05-03
• 期刊: URBAN CLIMATE
• 影响因子: 6.4
• 作者: Kasmalkar, Indraneel;Suckale, Jenny
• 通讯作者: Suckale, Jenny