1. Department of Earth Sciences; Uppsala University; Villavägen 16 Uppsala 75236 Sweden
2. GFZ German Research Centre for Geosciences; Telegrafenberg 14473 Potsdam Germany
3. Sintef Petroleum Research; S.P. Andersens vei 15 B NO-7031 Trondheim Norway
4. Jilin University; Xi Min Zhu Street No. 938 Changchun China