1. a National Hydrology Research Institute, Department of the Environment , Ottawa , K1A 0E7 , Canada
2. c Department of Metallurgy and Materials Science , McMaster University , Hamilton, Ontario , L8S 4L7 , Canada
3. d Institute for Marine Dynamics , National Research Council of Canada , Montreal Road, Ottawa , K1A 0R6 , Canada
4. b Groupes d'Etudes de Metallurgie Physique et de Physique des Materiaux , Institut National des Sciences Appliques de Lyon , 69621 , Villeurbanne Cedex , France