Results of the semblance analysis for the March 9 earthquake. Time scale is the same as Fig. 3. The time of 0 s on the records is 11:45:24 on March 9, 2011 (JST). (a) UD-component acceleration records in the 0.5–2 Hz band are shown. (b) Semblance, back-azimuth, and horizontal slowness are shown from top to bottom.