1026 Manju tsunami
| Local date | June 16, 1026 |
|---|---|
| Magnitude | MJMA 7.8 |
| Epicenter | 34°48′N 131°48′E / 34.8°N 131.8°E |
| Tsunami | 10 m (33 ft) |
| Casualties | >1,000 dead |
The 1026 Manju tsunami affected the Sea of Japan coast of the then Iwami Province on June 16. Considered one of the largest tsunamis in the Sea of Japan, it generated a tsunami with waves of 10 m (33 ft) at present-day Masuda, Shimane. Off the coast, an island reportedly sank because of the waves. More than 1,000 people were killed, and 3,000 homes were destroyed. The source of the tsunami has been debated between an earthquake or undersea landslide.