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Mount Unzen

Unzendake

Complex volcano · Japan · 1483m

The Unzen volcanic complex comprises much of the Shimabara Peninsula east of Nagasaki, seen here looking to the W from across Shimabara Bay. Three large edifices are visible: Kinugasa to the N, Fugendake in the E-center, and Kusenbu on the S. Historical eruptive activity has occurred at the summit and flanks of Fugendake. Activity during 1990-95 formed a lava dome at the summit that produced pyroclastic flows (block-and-ash flows).
The Unzen volcanic complex comprises much of the Shimabara Peninsula east of Nagasaki, seen here looking to the W from across Shimabara Bay. Three large edifices are visible: Kinugasa to the N, Fugendake in the E-center, and Kusenbu on the S. Historical eruptive activity has occurred at the summit and flanks of Fugendake. Activity during 1990-95 formed a lava dome at the summit that produced pyroclastic flows (block-and-ash flows). · Photo: Photo by Tom Casadevall, 1991 (U.S. Geological Survey). · Wikimedia Commons
Type
Complex volcano
Country
Japan
Region
Western Pacific Volcanic Regions / Nankai Volcanic Arc
Elevation
1483m
Coordinates
32.761, 130.299
Last eruption
1996
Tectonic setting
Subduction zone / Continental crust (> 25 km)
Landform
Composite
Major rock type
Andesite / Basaltic Andesite
Geological summary

The massive Unzendake volcanic complex comprises much of the Shimabara Peninsula east of the city of Nagasaki. An E-W graben, 30-40 km long, extends across the peninsula. Three large stratovolcanoes with complex structures, Kinugasa on the north, Fugen-dake at the east-center, and Kusenbu on the south, form topographic highs on the broad peninsula. Fugendake and Mayuyama volcanoes in the east-central portion of the andesitic-to-dacitic volcanic complex have been active during the Holocene. The Mayuyama lava dome complex, located along the eastern coast west of Shimabara City, formed about 4000 years ago and was the source of a devastating 1792 CE debris avalanche and tsunami. Historical eruptive activity has been restricted to the summit and flanks of Fugendake. The latest activity during 1990-95 formed a lava dome at the summit, accompanied by pyroclastic flows that caused fatalities and damaged populated areas near Shimabara City.

From Wikipedia

Mount Unzen is an active stratovolcano of several overlapping small, volcanic cones, near the city of Shimabara, Nagasaki on the island of Kyushu, Japan's southernmost main island.

Wikipedia · CC BY-SA · Read full article

Eruption history

Summary (VEI over time)
Click a bar to see individual eruptions
4050 BCE~3848 BCE · 1 eruptions · max VEI ?2841 BCE~2639 BCE · 2 eruptions · max VEI ?2236 BCE~2035 BCE · 1 eruptions · max VEI ?1632 BCE~1430 BCE · 1 eruptions · max VEI ?1229 BCE~1027 BCE · 1 eruptions · max VEI ?787~988 · 1 eruptions · max VEI ?1593~1794 · 4 eruptions · max VEI 21794~1996 · 3 eruptions · max VEI 24050 BCE2639 BCE1027 BCE3841794

Detailed timeline

  1. 1996VEI 2Observed
    1996-02-10 – 1996-05-01
    Fugen-dake
  2. 1990VEI 1Observed
    1990-11-17 – 1995-02-16
    Fugen-dake
  3. 1798VEI ?Geological estimate
    1798-11-13 – 1798-12
    Fugen-dake
  4. 1792VEI 2Observed
    1792-02-10 – 1792-07-22
    Fugen-dake (summit, NNE), Mayu-yama
  5. 1690VEI ?Geological estimate
    1690 – 1692
  6. 1663VEI 2Observed
    1663-04 – 1663-05
    Fugen-dake (Tsukumo-jima Pond)
  7. 1663VEI 2Observed
    1663-12-11 – 1663-12-27
    NE flank of Fugen-dake (1200 m)
  8. 860VEI ?Geological estimate
    860 – Ongoing
  9. 1150 BCE (±500 yrs)VEI ?Geological estimate
    BCE 1150 – Ongoing
    Fugendake-Sancho
  10. 1450 BCE (±500 yrs)VEI ?Geological estimate
    BCE 1450 – Ongoing
    Fugen-dake (Kazaana)
  11. 2150 BCE (±800 yrs)VEI ?Geological estimate
    BCE 2150 – Ongoing
    Mayu-yama (Tengu-yama)
  12. 2640 BCE (±500 yrs)VEI ?Geological estimate
    BCE 2640 – Ongoing
    Mayu-yama (Shichimen-zan)
  13. 2720 BCE (±300 yrs)VEI ?Geological estimate
    BCE 2720 – Ongoing
    Fugen-dake
  14. 4050 BCE (±3000 yrs)VEI ?Geological estimate
    BCE 4050 – Ongoing
    Fugen-dake (Shimanomine)

External links

⚠ For reference only. Not for emergency response.