Simultaneous acoustic, electrical, and X-ray computed tomography laboratory measurements of partially saturated permafrost degradation Available to Purchase

We present preliminary results of simultaneous laboratory experiments to measure the impact of permafrost thawing on geophysical properties of partially-saturated frozen sediment samples. Coincident acoustic, electrical resistivity and X-ray computed tomography measurements are conducted on synthetic permafrost samples to determine the behavior of the fluid and the matrix during thawing. Results suggest that attenuation for sample with the higher salinity increased by 15 dB in comparison to the lower salinity sample. Also, according to electrical resistivity, temperature variation has a greater influence on the low salinity sample. CT images showed that permafrost degradation reduced the cohesiveness of the sediments. This increases attenuation and porosity. Finally, fine-scale and complex interactions between the matrix and saline fluids affecting effective porosity, are suspected during permafrost thaw. However, this requires further analyses before it can be confirmed.