1968 Hyūga-nada earthquake
The 1968 Hyūga-nada earthquake (Japanese: 1968年日向灘地震) occurred on April 1 at 09:42 local time. The earthquake had a magnitude of Mw 7.5, and the epicenter was located in Hyūga-nada Sea, off the islands of Kyushu and Shikoku, Japan.
Source: Wikipedia — 1968 Hyūga-nada earthquake (CC BY-SA 4.0)