Profiles of Temporal Thaw Depths Beneath Two Arctic Stream Types Using Ground-Penetrating Radar

• Published in: Permafrost and Periglacial Processes
• Main Authors: Brosten, Troy R., Bradford, John H., McNamara, James P., Zarnetske, Jay P., Gooseff, Michael N., Bowden, W. Breck
• Format: Text
• Language: unknown
• Published: ScholarWorks 2006
• Subjects: ground-penetrating radar; permafrost; thaw bulb; arctic streams; Geosciences; Earth Sciences; Geophysics and Seismology; Arctic
• Online Access: https://scholarworks.boisestate.edu/cgiss_facpubs/79; https://doi.org/10.1002/ppp.566

Thaw depths beneath arctic streams may have significant impact on the seasonal development of hyporheic zone hydraulics. To investigate thaw progression over the 2004 summer season we acquired a series of ground-penetrating radar (GPR) profiles at five sites from May–September, using 100, 200 and 400 MHz antennas. We selected sites with the objective of including stream reaches that span a range of geomorphologic conditions on Alaska's North Slope. Thaw depths interpreted from GPR data were constrained by both recorded subsurface temperature profiles and by pressing a metal probe through the active layer to the point of refusal. We found that low-energy stream environments react much more slowly to seasonal solar input and maintain thaw thicknesses longer throughout the late season whereas thaw depths increase rapidly within high-energy streams at the beginning of the season and decrease over the late season period.