The 1662 earthquake caused the most damage of any earthquake that occurred in this location. The stone walls of castles collapsed at Nobeoka, Takanabe, Sadowara, and Obi, and many houses were completely collapsed. The focal region is thought to have been in southern Hyuganada Sea (Fig.9-8). Ground subsidence occurred simultaneously with the earthquake at the mouths of the Oyodogawa and Kaetagawa Rivers. A tsunami from 4 to 5 m high is thought to have struck the area, killing 15 and flooding many houses and fields. The fields were also flooded by sea water in Nobeoka. Details are unclear, but the damage also could have extended to the Osumi area.

The 1961 earthquake is thought to have been an interplate earthquake, and seismic intensity 5 in JMA scale was observed in Miyazaki City, Aburatsu (now Nichinan (Nitinan)), and Miyakonojo (Miyakonozyo) (Fig.9-9). Three people were injured in Miyazaki City, and several of houses were completely collapsed. Ground subsidence also occurred along the Oyodogawa River and at airport runways, and gas and water pipes were damaged. Houses were damaged in Nichinan, near the hypocenter of the earthquake. A landslide claimed one victim in Shibushi (Sibusi) (Fig.9-10, Fig.9-11). Also, a small tsunami struck Aburatsu about 1 minute after the earthquake occurred. The aftershocks gradually decreased (Fig.9-12).

Judging from the damage caused by the tsunami, the seismic ground motion, and other factors, the 1961 earthquake occurred in a relatively deep location near land. The 1662 earthquake, which had a larger tsunami, is likely to have had its hypocenter in a shallow area in the open sea.