Ice content is a critical variable in the context of thawing permafrost, and permafrost cores provide a means to measure the characteristics of frozen ground; however, these measurements are typically destructive and time intensive. Multi-sensor core logging (MSCL) provides a fast, non-destructive method to image permafrost cores, measure bulk density, and estimate ice content. The use of MSCL will improve existing digital permafrost archives by adding high-quality and reproducible data.

Long-term temperature measurements are challenging to carry out in mountain-permafrost boreholes. The widely used resistance thermistors are highly accurate but prone to drift when they are exposed to moisture, or the cable connecting them is stretched. We explore the possibility of supplementing them with digital sensors and analyse the performance of both systems at 15 depths in the same mountain-permafrost borehole.

The microstructure of permafrost soils contains clues to its formation and its preconditioning to future change. We used X-ray computed tomography (CT) to measure the composition of a permafrost drill core from Siberia. By combining CT with laboratory measurements, we determined the the proportions of pore ice, excess ice, minerals, organic matter, and gas contained in the core at an unprecedented resolution. Our work demonstrates the potential of CT to study permafrost properties and processes.

This study presents the development and validation of a novel acquisition system for measuring finely resolved depth profiles of soil and snow temperature at multiple locations. Results indicate that the system reliably captures the dynamics in snow thickness, as well as soil freezing and thawing depth, enabling advances in understanding the intensity and timing in surface processes and their impact on subsurface thermohydrological regimes.

A simple method to record heave and subsidence of the land surface at specific field locations is described. Hourly observations from three sites, over two winters and one summer, are analyzed and discussed. The data are rich in features that point to the influence of freezing and thawing and of wetting and drying of the soil. This type of observation may offer new insight into the processes of heat and mass transfer in soil and help to monitor climate change impacts.