抄録
Hydrographic Department of Japan conducted seasur face gravity and magnetic survey of Tatibana Bay in June, 1991 to elucidate seabottom structure in relation with volcanic eruption of Unzen volcano. Precise gravity and magnetic anomaly maps of Tatibana Bay show a caldera structure and an intrusive voccanic activity related with caldera formation. Horizontal distribution of shallow seismic epicenters are in good agreement with local magnetic anomaly zone, which may indicate a intrusive volcanic activity are still in active below Tatibana Bay.
