Fig. 4From: Structural heterogeneity in and around the fold-and-thrust belt of the Hidaka Collision zone, Hokkaido, Japan and its relationship to the aftershock activity of the 2018 Hokkaido Eastern Iburi EarthquakeResults of checker board test. a Case for anomaly size of 20 km (Horizontal) x 5 km (vertical). Shot positions used in the tomography analysis are indicated by triangles. b Case for anomaly size of 10 km x 3 kmBack to article page