1. The University of Edinburgh, School of GeoSciences, Grant Institute, Edinburgh, U. K.; Edinburgh Collaborative of Subsurface Science and Engineering, Edinburgh, U. K.; and WesternGeco London Technology Centre, West Sussex, U. K. .
2. Formerly University of Edinburgh, School of Geosciences, Grant Institute, Edinburgh, U. K., and Edinburgh Collaborative of Subsurface Science and Engineering, Edinburgh, U. K.; presently Schlumberger Cambridge Research, Cambridge, U. K. .