Department of Earth Sciences, University of Aarhus, Hoegh Guldbergs Gade 2, Aarhus C, DK-8000 Denmark
Earth Science Institute, University of Iceland, Askja, Sturlugata 7, Reykjavik, IS-101 Iceland ;
Laboratory of Geographic Information Science, East China Normal University, East China Normal University, Shanghai, 200062 China ;
Department of Earth Sciences, University of Aarhus, Hoegh Guldbergs Gade 2, Aarhus C, DK-8000 Denmark ; Earth Science Institute, University of Iceland, Askja, Sturlugata 7, Reykjavik, IS-101 Iceland ;
Laboratory of Geographic Information Science, East China Normal University, East China Normal University, Shanghai, 200062 China ;