ABSTRACT

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 Utqia?vik, 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 Utqia?vik, 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.

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