1. University of Oslo, Department of Geosciences, Sem Sælands vei 1, 0371 Oslo, Norway, and CGG..
2. CGG..
3. University of Oslo, Department of Geosciences, Sem Sælands vei 1, 0371 Oslo, Norway, and Lundin Norway AS, Strandveien 4, 1366 Lysaker, Norway..
4. University of Oslo, Department of Geosciences, Sem Sælands vei 1, 0371 Oslo, Norway..