Unzen volcano eruptions
stratovolcano 1486 m / 4,875 ft
Kyushu, Japan, 32.76°N / 130.29°E
Eruption list: 1996, 1990-95, 1798(?), 1792, 1690-92, 1663, 1663, 860(?)
In 1991, Unzen woke up from its 200-year slumber and started to extrude a new lava dome at the summit. The eruption quickly intensified, and in June, repeated collapses of the new lava dome generated pyroclastic flows that swept down its slopes at speeds as high as 200 kilometers per hour. The largest flow occurred on June 3, 1991 and killed 43 people caught by surprise by the unusually strong flow.
1792 landslide-triggered tsunami disaster at Unzen volcano
Unzen is infamous for Japan's greatest volcanic disaster. In 1792, about a month after lava stopped erupting from the volcano, a landslide from nearby Mount Mayuyama swept through ancient Shimabara City, entered the sea, and generated a tsunami that struck nearby areas.
More than 15,000 people were killed by the landslide and tsunami. The amphitheater-shaped scar of the landslide is still clearly visible on Mount Mayuyama just above the city.
From: Brantley and Scott, 1993, The Danger of Collapsing Lava Domes: Lessons for Mount Hood, Oregon: IN: Earthquakes & Volcanoes, v.24, n.6