1. R. J. Geller is at the Department of Earth and Planetary Physics, Faculty of Science, Tokyo University, Yayoi 2-11-16, Bunkyo-ku, Tokyo 113, Japan.
2. D. D. Jackson and Y. Y. Kagan [–] are at the Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095-1567, USA.and
3. F. Mulargia is at the Dipartimento di Fisica, Settore di Geofisica, Universita di Bologna, Viale Berti Pichat 8, 40127 Bologna, Italy.