Erik C Sturkell, University of Gothenburg, Gothenburg, Sweden, Halldor Geirsson, University of Iceland, Faculty of Earth Sciences, Reykjavik, Iceland, Freysteinn Sigmundsson, University of Iceland, Nordic Volcanological Center, Institute of Earth Sciences, Reykjavik, Iceland, Benedikt Ofeigsson, Icelandic Meteorological Office, Reykjavik, Iceland, Gunnar Guðmundsson, Icelandic Met Office, Reykjavik, Iceland, Pall Einarsson, Science Institute, University of Iceland, Nordic Volcanological Center, Institute of Earth Sciences, Reykjavik, Iceland, Sigrun Hreinsdottir, GNS Science, Lower Hutt, New Zealand and Finnur Pálsson, University of Iceland, Reykjavik, Iceland