Affiliation: | Institut für Geophysik, ETH Zürich, CH-8093;Zürich, Switzerland. E-mail: Institute for Geophysical Research, University of Alberta, T6G 2J1,;Edmonton, Alberta, Canada Department of Geology, Northwest University, 710 069;Xi'an, Shaanxi Province, China Fachbereich Geowissenschaften, Universität Bremen, Postfach 320440, D-283334;Bremen, Germany |