Fig. 15

Relationship between slip rate estimated from GPS (Hashimoto et al. 2012) and repeating earthquakes (Nomura et al. 2017) in the Tohoku subduction zone for the period from 1996 to 2000 (modified from Nomura et al. (2017)). a shows the spatial distribution of GPS slip deficit/excess rate by Hashimoto et al. (2012) and b displays the repeater-derived slip rate for the period of 1996–2000 for comparison. The contour interval for the slip deficit is 3 cm/year. Green contours in a show the coseismic slip distribution of the 2011 Tohoku-oki earthquake (M9) at a contour interval of 4 m. Orange star shows the epicenter of the Tohoku-oki earthquake. White and orange circles show foreshocks on March 9 and the aftershocks for March 11–14, respectively. The thin black contours represent depth to plates in 10 km interval. The black and white circles in b represent repeating earthquakes within and outside the 1996–2000 time period, respectively. The slip rate at 60-km-depth or larger is masked since there are almost no data constraints. Thick green line is 4 m coseismic slip shown in a. c Slip deficit rates at ~ 50 km grid points on the plate interface shallower than 80 km are sampled and converted to slip rate by assuming a plate convergence rate of 8.5 cm/year. The straight gray line (slope = 0.19, intercept = 2.0) indicates the least-squares fit to the data