Search for: All records

The Arctic is experiencing accelerated warming at up to four times the rate of temperate regions, driving permafrost thawing and ground ice melting, which, in turn lead to coastal bluff failure and accelerated erosion. The primary mechanisms behind Arctic coastal bluff failures include the formation of thermoerosional niches at the bluff’s toe and warming-induced reductions in ground strength, making Arctic coastal bluff failure a complex thermal-mechanical coupling process. Most existing studies have focused on coastal bluff failures in temperate regions, but the unique failure mechanism in the Arctic remain underexplored. This study addresses this gap by developing a thermalmechanical coupling model to study the failure mechanism of a permafrost bluff failure that occurred in 2023–2024 in Utqia˙gvik, Alaska. The model incorporates pore ice phase change, thaw-induced reductions in permafrost stiffness and strength, and the effects of thermoerosional niches, cracks, and ice wedges. Stability analysis is conducted via the local factor of safety (LFS) method to account for spatial variations in permafrost strength and stiffness. Ground-penetrating radar (GPR) data from the August 2024 site survey were employed to characterize site conditions, and ground temperature data were used to validate the model. The results revealed two primary failure zones: one near the ground surface and another at the bluff’s toe. The total area of these two failure zones expanded with ongoing thaw. Besides, the results indicated that the increase in thaw thickness, the growth in niche length, and the presence of cracks exacerbate bluff instability, and bluff failure is likely to initiate along the ice wedge–permafrost interface. 

In June 2023, one faculty member and two undergraduate students in civil engineering at Pennsylvania State University collaborated with Iḷisaġvik College to host the 2023 STEM Summer Camp in Utqiaġvik, Alaska. The 5-day camp accommodated 16 Indigenous Alaskan middle school students with the goal to foster the next generation in STEM careers in Arctic Alaska. The camp included hands-on, competitive activities and region-specific experimental activities. Trips to local research and cultural centers provided insight into STEM career opportunities. The camp piqued students’ interest in STEM subjects and STEM-related careers and equipped them with some foundational knowledge to advance their studies. In preparation for the 2024 STEM summer camp again in Utqiaġvik, the organizers partnered with a local middle school in State College, PA, to host a series of STEM activities. This paper presents these STEM activities, lessons learned, and areas for future improvement. 

Abstract Subsurface processes significantly influence surface dynamics in permafrost regions, necessitating utilizing diverse geophysical methods to reliably constrain permafrost characteristics. This research uses multiple geophysical techniques to explore the spatial variability of permafrost in undisturbed tundra and its degradation in disturbed tundra in Utqiaġvik, Alaska. Here, we integrate multiple quantitative techniques, including multichannel analysis of surface waves (MASW), electrical resistivity tomography (ERT), and ground temperature sensing, to study heterogeneity in permafrost’s geophysical characteristics. MASW results reveal active layer shear wave velocities (V_s) between 240 and 370 m/s, and permafrostV_sbetween 450 and 1,700 m/s, typically showing a low‐high‐low velocity pattern. Additionally, we find an inverse relationship between in situV_sand ground temperature measurements. TheV_sprofiles along with electrical resistivity profiles reveal cryostructures such as cryopeg and ice‐rich zones in the permafrost layer. The integrated results of MASW and ERT provide valuable information for characterizing permafrost heterogeneity and cryostructure. Corroboration of these geophysical observations with permafrost core samples’ stratigraphies and salinity measurements further validates these findings. This combination of geophysical and temperature sensing methods along with permafrost core sampling confirms a robust approach for assessing permafrost’s spatial variability in coastal environments. Our results also indicate that civil infrastructure systems such as gravel roads and pile foundations affect permafrost by thickening the active layer, lowering theV_s, and reducing heterogeneity. We show how the resultingV_sprofiles can be used to estimate key parameters for designing buildings in permafrost regions and maintaining existing infrastructure in polar regions.