To model the future stability of infrastructure requires accurate high-resolution models of the subsurface and knowledge of the mechanical consequences of rising temperatures, none of which is readily available today. This project aims to develop accurate, quantitative geophysical subsurface characterization methods along with methodologies for the use the geophysics to map permafrost degrading in an infrastructure setting.
Permafrost is warming on the global scale by approximately 0.3˚C per decade and as a result, Arctic communities are fighting many social and economic challenges with very limited resources. Almost 25% of the population in Greenland lives in communities that are challenged by permafrost issues such as differential settlements and natural disasters caused by progressive warming and deepening of the active layer.
In spite of the urgency, there are yet no sufficient subsurface methods to accurately constrain the state of thermal degradation in subsurface materials, nor models to describe the mechanical consequences of warming and thawing rock masses and soils. This limits the opportunities for assessing stability problems with permafrost degradation and therefore assessing long-term effects that infrastructure encounter.
Geophysics have the potential to in a cost effective way supply the high resolution subsurface information needed in stability modelling, but permafrost has a unique set of challenges that limits the resolution of geophysical methods. Issues like Equivalency, low velocity zones and non-uniqueness of the inversion problem have shown that no one method are able to resolve the subsurface adequately. Therefore, we aim to develop accurate, quantitative geophysical subsurface characterization methods for warming and thawing rock masses and soils. To overcome the problems listed above, a joint inversion set up is under development to combine multiple near surface geophysical datasets relevant to the artic to be able to supply adequate subsurface models.
The geophysical parameters in itself does not supply the need information for modelling of stability. Therefor a series of lab experiments will be performed to benchmark and set up rock physical relations between the measurable geophysical parameters and soil parameters of interest. The lab tests will also supply insides on the consequences of warming and thawing of soils. Combining the geophysics and the calibrated rock physical models we hope to develop methodology to supply the needed information to estimate the future stability of infrastructure in the artic.
Duration of the project:
2020-2023
Funding agency:
Internal DTU funding
Project partners and collaborators:
DTU & Technical University of Munich