SitS: Collaborative Research: Understand and forecast long-term variations of in-situ geophysical and geomechanical characteristics of degrading permafrost in the Arctic

气候变化正在导致北极和亚北极地区的永久冻土变暖，从而导致土壤的地质和力学性质发生变化。量化土壤性质的变化对于了解自然环境和评估这些变化对现有和未来建成的基础设施的影响至关重要，这两者都具有长期的社会影响。该项目将把光纤传感电缆埋入阿拉斯加沿海社区的地下。光纤传感信号将被转换为地面材料的地质和地质力学性质，然后用于定量预测未来对永久冻土性质的影响。项目成果将使人们能够现实地评估北极阿拉斯加基础设施的性能，并改进北极地区更强大的基础设施的设计。研究小组将通过融合研究积极招募和培训女科学家和工程师，研究小组将参与阿拉斯加土著社区UtqiaġVik的教育和外联活动。该项目的目标是利用创新的传感技术、数据传输和分析以及建模，了解和预测北极阿拉斯加活动层和永久冻土的现场地球物理和地球力学特征的长期变化。通过在传感器系统和建模方面的进展，该项目将改变理解北极沿海社区活动层和永冻层中动态的近地表土壤过程的现有能力，从而产生关于气候变化导致的北极长期和就地永冻土退化的量化知识。将进行五项工作：(1)在阿拉斯加州乌特基亚ġVik开发和部署长达1.5公里的光纤分布式声波传感阵列，用于多年冻土的长期原位监测；(2)创新多年冻土中光纤分布式声波传感信号的数据传输和分析，得出随温度变化的多年冻土S波和P波速度剖面；(3)通过现场和实验室表征，获得地球物理和地质力学性质的地面真实测量；(4)建立多年冻土的地球物理、地质力学性质与S波、P波速度的关联式，以及多年冻土温度与S波、P波速度的关联式，预测未来多年冻土退化的地球物理、地质力学性质变化。研究成果将直接为阿拉斯加北坡地区当前的基础设施评估和未来的基础设施发展提供信息。该项目开发的方法将在北极和亚北极地区提供具有变革性和成本效益的地球物理和岩土技术监测。该奖项是通过国家科学基金会和美国农业部国家粮食和农业研究所(USDA NIFA)之间的合作伙伴关系“土壤中的信号(SITS)”征集而颁发的。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Climate change is resulting in warming of the permafrost across the Arctic and sub-Arctic, which results in changes in the geological and mechanical properties of soils. Quantifying the changes in soil properties are critical for both understanding the natural environment and assessing the effects of these changes on the existing and future built infrastructure, both of which have long-lasting societal impacts. This project will embed fiber optic sensing cables into the ground in an Alaskan coastal community. Fiber-optic-sensed signals will be converted into the geological and geomechanical properties of the ground material and then used to quantitatively forecast future impacts on permafrost properties. The project outcomes will enable realistic evaluation of the performances of infrastructure in Arctic Alaska and improve the design of more robust infrastructure in the Arctic. The research team will actively recruit and train women scientists and engineers through convergent research, and the research team will be involved in educational and outreach activities in Utqiaġvik, Alaska’s indigenous community.The goal of this project is to understand and forecast long-term variations of in-situ geophysical and geomechanical characteristics of the active layer and permafrost in Arctic Alaska using an innovative sensing technology, data transmission and analysis, and modeling. Through advances in sensor systems and modeling, the project will transform existing capabilities for understanding dynamic, near-surface soil processes in the active layer and permafrost in an Arctic coastal community, thus generating quantitative knowledge of long-term and in-situ permafrost degradation in the Arctic due to climate change. Five tasks will be conducted: (1) develop and deploy a 1.5-kilometer-long fiber-optic distributed acoustic sensing (DAS) array in Utqiaġvik, Alaska for long-term in-situ permafrost monitoring; (2) develop innovative data transmission and analysis of DAS signals in permafrost and derive temperature-dependent S-wave and P-wave velocity profiles of changing permafrost in spatial and temporal scales; (3) obtain ground-truth measurements of geophysical and geomechanical properties through in-situ and laboratory characterizations; (4) develop correlations between geophysical and geomechanical properties of permafrost and S- and P-wave velocities as well as between permafrost temperature and S- and P-wave velocities; and (5) forecast future changes of geophysical and geomechanical properties of degrading permafrost. Research outcomes will directly inform current infrastructure evaluation and future infrastructure development in the North Slope Borough, Alaska. Methodology developed in this project will provide transformative and cost-effective geophysical and geotechnical monitoring in the Arctic and sub-Arctic regions.This award was made through the "Signals in the Soil (SitS)" solicitation, a collaborative partnership between the National Science Foundation and the United States Department of Agriculture National Institute of Food and Agriculture (USDA NIFA).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.