1. HM Research Norway AS, Tananger, 4056 Stavanger, Norway
2. School of Energy, Geoscience, Infrastructure and Society, Heriot-Watt University, Edinburgh EH14 4AS, UK
3. Department of Earth Science, University of the Western Cape, Private Bag X17, Cape Town 7535, South Africa
4. School of Geosciences, University of Aberdeen, Aberdeen AB24 3UE, UK