Paul Spudich U.S. Geological Survey, MS977, Menlo Park, CA 94025 USA spudich@usgs.gov

Mariagiovanna Guatteri Dept of Geophysics, Stanford Univ., Stanford, CA 94305 USA patti@pangea.stanford.edu

Kenshiro Otsuki Dept of Geoenvironmental Sciences, Tohoku Univ., Sendai 980, JAPAN otsuki@dges.tohoku.ac.jp

Jun Minagawa Dia Consultants Co. Ltd., Ikebukuro 3-1-2, Toshima-ku, Tokyo 171, JAPAN, J.Minagawa@gen.diaconsult.co.jp

Acknowledgements We thank R. Ikeda, H. Ito, and H. Tsukahara who provided much information about their borehole results in advance of publication, and to S. Hickman, who helped us interpret it. S. Ide, D. Wald, and S. Yoshida provided digital versions of their slip models. A.M. Boullier, J.P. Gratier, P. Montone, D. Pantosti, and L. Valensise gave us much information about striation observations and alerted us to the implications of our work for structural geology. P. Stark helped us understand the implications of uninformative priors. C. Prentice provided additional striation information. We thank M. Bouchon, H. Kawase, C. Prentice, D. Wald, and an anonymous reviewer for constructive reviews. We thank Leonardo Proietti for constructing this web page.