December 12, 2012 Dr. Kenji Yoshikawa, Perennial and seasonal frost mounds hydrology based on ice cored stable isotope data Research Professor of Water Resources, Institute of Northern Engineering, Water and Environmental Research Center, University of Alaska Fairbanks

Perennial and seasonal frost mounds hydrology based on ice cored stable isotope data

Dr. Kenji Yoshikawa, Research Professor of Water Resources, Institute of Northern Engineering, Water and Environmental Research Center, University of Alaska Fairbanks

The first entire record of stable isotopes (?18O/?D) in pingo ice within both an open- and a closed-system pingos indicates a complex history of ice formation and pingo growth. A continuous section of ice was cored through the center of pingos, palsas, frost blisters as well as icing blisters. Ice cores were analyzed for stable isotope, chemical compositions, for all types and sub-pingo water hydrology for an open system pingo. Changes in the isotopic signature of the ice core with depth signals several distinct patterns by which the pingo grew as permafrost aggradation or groundwater hydrology was changing. In the initial stages, in-situ water migrating toward the freezing front froze at a relatively rapid rate as revealed by the complex isotopic record. In the middle and lower most sections of the cores, characterized very unique signals that considered different forming process to develop open- and closed- system pingos. I will not discuss only the inside of pingos for this meeting but I will also talk about the distributions and characteristics of frozen mounds in Alaska.