Microstructural Characterization of Arctic Permafrost and Sea Ice From the Microscale to the Nanoscale Using X-Ray Microscopy

Understanding the evolving state of the Arctic's upper permafrost and sea ice is crucial for tracking environmental effects, yet little is known about the nanostructure and distribution of microbial life within these environments. Recent advances in X-ray computed tomography technology have made it possible to image environmental samples not only at micron-scale resolution, but also at the nanoscale. Here we present high resolution images of permafrost and sea ice samples collected from Alaska, Nunavut, and Greenland. We have developed advanced segmentation techniques to characterize the microstructure, tracking variables such as porosity with depth. We have also developed techniques to use osmium staining to image microbes in situ within these samples at the nanoscale. At this resolution, we seek to connect physical and biological attributes of terrain state to improve our understanding of microbial distributions and microbially-mediated processes in cold regions.