Earthquake Swarm in the Hida Mountain Region, Central Japan School of Sciense, Nagoya University 1998 8 7 7 14 M4.7 10 12 8 16 M5.4 8 27 9 5 M4.6 9 19 1998 8 7 1998 10 3 Fig.1 Earthquake epicenters in the Hida mountain region (Aug. 7, 1998-Oct. 3, 1998). Fig.2 Focal depth distribution in 4 areas. a) b) c) Fig.3 Space-time plots in the Hida mountain region. a) Space-time plots ( NS-direction). b) S