Introduction

Unzen is a group of several overlapping active stratovolcanoes (including Kinugasa on the north, Fugen-dake at the east-center, and Kusenbu on the south) located near the city of Shimabara, Nagasaki Prefecture, on the island of Kyushu, Japan's southernmost main island. The massive basaltic to andesitic Unzen volcanic complex occupies much of the Shimabara Peninsula east of Nagasaki. Currently, Unzen's highest peaks are Fugendake (普賢岳) at 1,359 metres (4,459 ft) and Heisei Shinzan (平成新山) at 1,486 metres (4,875 ft).
The volcanoes formed along a 30-40 km long E-W aligned graben. The historically active vent of Unzen, Mayu-yama lava dome complex, is about 4,000 years old.
In 1792, the collapse of one of its several lava domes triggered a tsunami that killed about 15,000 people in Japan's worst-ever volcanic-related disaster. The last eruptions of the volcano were from 1990 to 1995. The largest eruption in this period occurred on June 3, 1991, when a pyroclastic flow that reached 4.5 kilometres distance from the crater killed 43 people including the famous French volcanologists Katia and Maurice Krafft.



See also: Sentinel hub | Landsat 8