Fig. 1.

Map gives the horizontal components of the transient deformation field between the time of the foreshock and the mainshock as estimated by the NSF. Panels on the right show the east component time series for the 4 stations denoted by the red triangles on the map with three or four digits of station code (910: Esashi, 911: Iwate-Ohigashi, 914: Miyagi-Towa, 1145: Iwate-Kawasaki-A). The blue dots are the JPL 30-min solutions minus our estimate of the reference frame error. The red line is the sum of the benchmark, transient, and Heaviside components of the time series as estimated by the NSF. The black curve is the transient deformation field as estimated by the filter. The y-axis of each time series plot is in meters.