• Geophysical Applications for Arctic/Subarctic Transportation Planning

      Schnabel, William E.; Fortier, Richard; Kanevskiy, Mikhail; Munk, Jens; Shur, Yuri; Trochim, Erin (Alaska University Transportation Center, 2014-07)
      This report describes a series of geophysical surveys conducted in conjunction with geotechnical investigations carried out by the Alaska Department of Transportation and Public Facilities. The purpose of the study was to evaluate the value of and potential uses for data collected via geophysical techniques with respect to ongoing investigations related to linear infrastructure. One or more techniques, including direct-current resistivity, capacitive-coupled resistivity, and ground-penetrating radar, were evaluated at sites in continuous and discontinuous permafrost zones. Results revealed that resistivity techniques adequately differentiate between frozen and unfrozen ground, and in some instances, were able to identify individual ice wedges in a frozen heterogeneous matrix. Capacitive-coupled resistivity was found to be extremely promising due to its relative mobility as compared with direct-current resistivity. Ground-penetrating radar was shown to be useful for evaluating the factors leading to subsidence in an existing road. Taken as a whole, the study results indicate that supplemental geophysical surveys may add to the quality of a geotechnical investigation by helping to optimize the placement of boreholes. Moreover, such surveys may reduce the overall investigation costs by reducing the number of boreholes required to characterize the subsurface.
    • GeoTechnical Investigations for the Dalton Highway Innovation Project As A Case Study of the Ice-Rich Syngenetic Permafrost

      Shur, Yuri; Kanevskiy, Mikhail; Dillon, Matthew; Stephani, Eva; O’Donnell, Jonathan (Alaska University Transportation Center, Alaska Department of Transportation and Public Facilities, 2010)
    • Permafrost Database Development, Characterization, and Mapping for Northern Alaska

      Jorgenson, M. Torre; Kanevskiy, Mikhail; Shur, Yuri; Grunblatt, Jess; Ping, Chien-Lu; Michaelson, Gary (2014-10-31)
    • Risk Evaluation for Permafrost-Related Threats:Methods of Risk Estimation and Sources of Information

      Kanevskiy, Mikhail; Connor, Billy; Schnabel, Bill; Shur, Yuri; Bjella, Kevin; Trochim, Erin; Dean, Kelsey; Ellison, Ariel (2019-05)
      In our evaluation of permafrost-related threats that affect Alaska communities, we have focused on threats associated with permafrost degradation and thawing ground ice, which can result in significant thaw settlement and cause unacceptable damage to engineered structures. Our evaluation system for permafrost-related threats includes risks of general permafrost degradation and thaw settlement (general and differential). We have evaluated permafrost-related threats for 187 Alaska villages based on available information including scientific publications, maps, satellite imagery and aerial photographs, geotechnical reports, personal communication, community plans and reports, and other sources. Evaluation was based on five criteria: permafrost (PF) occurrence; PF temperature; thaw susceptibility of frozen soils (expected thaw settlement in case of permafrost degradation); massive ice occurrence; and existing PF-related problems. For each of these categories, four risk levels (ranks) were considered. The total (cumulative) risk level was based on the rating score (sum of individual ranks for all five categories). Based on the rating score, each village was assigned one of four risk levels: 0 – no permafrost; 5–8 – low risk level; 9–11 – medium risk level; 12–15 – high risk level. A vulnerability score was developed for each community allowing the identification of communities with the highest risk of damage due to thawing permafrost. Most of communities with the high-risk level (22 villages of 34) are underlain by continuous permafrost, while the low risk level is typical mainly of communities underlain by predominantly unfrozen soils/bedrocks (33 villages of 46), and no high risk levels were detected for this group of villages. Medium risk level is typical mainly of communities underlain by discontinuous and sporadic permafrost (35 villages of 47); some villages of this group are characterized by high and low risk levels (12 and 9, correspondingly). Occurrence of massive-ice bodies (mostly ice wedges) is typical exclusively of communities underlain by continuous and discontinuous permafrost (23 and 20 villages, correspondingly). We presume that at least 20 communities may have extremely ice-rich yedoma deposits with large ice wedges either within villages or in their vicinity. Permafrost conditions in Alaskan communities are very diverse, and in many cases they are extremely variable even within the same community. Detailed studies are required for more precise evaluation of potential permafrost-related threats associated with permafrost degradation and/or thawing of ground ice.