1. High Mountain Physical Geography Research Group; Department of Geography; Complutense University of Madrid; Madrid 28040 Spain
2. Faculty of Life and Environmental Science; University of Iceland; Öskju, Sturlugötu 7 Reykjavík 101 Iceland
3. Icelandic Institute of Natural History; Borgum við Norðurslóð, Box 180 Akureyri 602 Iceland