Affiliation: | Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Madingley Rise, Madingley Road, Cambridge CB3 0EZ;NTNF/NORSAR, Post Box 51, N-2007 Kjeller, Norway;Seismological Observatory, University of Bergen, Allegt. 41, N-5014 Bergen U, Norway;NTNF/NORSAR, Post Box 51, N-2007 Kjeller, Norway |