Fig. 1
From: Earthquakes in Oita triggered by the 2016 M7.3 Kumamoto earthquake
a Epicenters of M ≥ 3 aftershocks in the Oita area from April 16 to May 31, 2016, listed in the JMA earthquake catalog. The green diamond denotes the epicenters of the M5.7 event (semiofficial value by JMA) relocated in this study, which occurred immediately after the mainshock. The arrow indicates the hypocenter location of the M5.7 event determined by JMA. The red squares denote the K-NET and KiK-net stations used in this study. Assumed normal faults with a dip of 70° for calculating surface displacements are also shown. For M5.7 models (solid line), L = 11.2 km, W = 5.1 km, and slip = 35.5 cm. For M6.0 models (dotted line), L = 16 km, W = 8 km, slip = 50 cm. b Depth section of hypocenters and assumed M 5.7 faults. The top and bottom depths are 5.4 and 10.6 km (red), 3.4 and 8.6 km (orange), and 1.4 and 6.6 km (green). c Assumed M6.0 faults with top and bottom depths of 6.2 and 13.8 km (red), 4.2 and 11.8 km (orange), and 2.2 and 9.8 km (green). d Epicenters of M ≥ 2 events from April 14 to May 31. The blue circle shows the M7.3 mainshock of April 16. The box denotes the area shown in a