1. Department of Earth SciencesUniversity of Western Ontario 1151 Richmond Street, N6A 5B7, London ON Canada.
2. ARKK Engineering #168 2301 Premier Way, T8H 2K8 Edmonton AB Canada.
3. Cold Regions Research CentreWilfrid Laurier University 75 Avenue West, N2L 3C5 Waterloo ON Canada.
4. Department of GeoscienceUniversity of Calgary 2500 University Dr. N.W., T2N 1N4 Calgary AB Canada.