October 30, 1662 Earthquake: Hiuganada, Japan

A strong earthquake was felt in Miyazaki and Kagoshima Prefectures. The tremors were especially strong along the entire caost of Hyuga-Nada. The earthquake caused some changes in coastal relief on a stretch of 160 km. At Sadoawara, the gates of the castle were destroyed, as well as homes and temples; in all about 800 homes collapsed in the rural locality; there were human victims; cracks up to 1 m appeared in the ground; avalanches occurred. There were many aftershocks, which continued on the following day. Near Miyazaki, 90 homes were destroyed and 120 were half-destroyed. A stretch of coast 32 km long near Kaeda and Hongo subsided under the sea. A tsunami followed the earthquake. (reference #414)

The largest earthquake in history in the Hyuganada subduction zone was the 1662 Hyuga-nada earthquake (M7.25–7.75), which occurred off Miyazaki Prefecture in the southeastern part of the Kyushu region (Usami, 2003) and generated a tsunami (Watanabe, 1998). Tens of people died, and a few thousand structures were damaged by the earthquake and the tsunami (Watanabe, 1998) […] From the damage to structures that occurred along the coast of Miyazaki Prefecture, it can be inferred that the JMA seismic intensity was high, up to a maximum of 6. Historical documents indicate local subsidence of about 1 m and changes at river currents of Oyodo and Kaeda in the Miyazaki plain (Hatori, 1985) […] To determine the tsunami source of the 1662 Hyuga-nada earthquake, we surveyed geological evidence of the tsunami and estimated the fault model of the earthquake […] From the fault model of the interplate earthquake, including the source area of slow earthquakes, the seismic moment of the 1662 Hyuga-nada earthquake was calculated to be 9.8 x 10^20 Nm (Mw 7.9), assuming a rigidity of 3.5 x 10^10 N/m^2. It is possible that the 1662 Hyuga-nada earthquake is the largest in Hyuga-nada in historical records, caused by large slip at the active source area of slow earthquakes. (reference #13668)