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Japan · Stratovolcano

Mount Chōkai

Chokaisan

Type
Stratovolcano
Elevation
2236m
Last eruption
1974
Mount Chōkai
Photo: kyohei ito · CC BY-SA 2.0 · Wikimedia Commons
Type
Stratovolcano
Country
Japan
Region
Northwestern Pacific / Northeast Japan Volcanic Arc
Elevation
2236m
Coordinates
39.099, 140.049
Last eruption
1974
Tectonic setting
Subduction zone / Continental crust (> 25 km)
Landform
Composite
Major rock type
Andesite / Basaltic andesite
Geological summary

Chokaisan is composed of two overlapping stratovolcanoes with a conical profile that inspired the local names of Akita-Fuji or Dewa-Fuji. The summit of the gently sloping western edifice (Nishi-Chokaisan) is cut by a large scarp open to the south that contains lava domes. The younger eastern volcano (Higashi-Chokaisan) began forming about 20,000 years ago, and also has a large scarp, breached to the north. An eruption about 2,600 years ago was the source of the voluminous Kisakata debris avalanche, which reached the Pacific coast. Two post-caldera lava domes have been constructed at the upper SE end of the caldera. Intermittent reports of eruptions date back to the 6th century CE.

From Wikipedia

Mount Chōkai is an active volcano located on the border of Akita and Yamagata in the Tōhoku region of Japan, and is 2,236 m (7,336 ft) tall. Because of its (roughly) symmetrical shape and massive size, it is also variously known as Dewa Fuji (出羽富士), Akita Fuji (秋田富士) or Shōnai Fuji (庄内富士) depending on the location of the viewer. In addition to being one of the 100 Famous Landscapes of Japan, it is also included as one of the 100 famous mountains in Japan, and famous 100 Geographical Features of Japan. It is surrounded by Chōkai Quasi-National Park. It is also a National Historic Site of Japan, and is regarded as a sacred mountain by followers of the Shugendō branch of Shinto which has the shrine Chōkaisan Ōmonoimi Shrine there and is popular with hikers.

Wikipedia · CC BY-SA · Read full article →

Eruption history

31 recordedGlossary
Summary (VEI over time)
Click a bar to see individual eruptions · Use arrow keys to move between bars, Enter to open
1050 BCE~861 BCE · 1 eruptions · max VEI 0672 BCE~483 BCE · 1 eruptions · max VEI ?483 BCE~294 BCE · 1 eruptions · max VEI ?462~651 · 3 eruptions · max VEI ?651~840 · 6 eruptions · max VEI ?840~1029 · 8 eruptions · max VEI 31407~1596 · 2 eruptions · max VEI ?1596~1785 · 5 eruptions · max VEI 21785~1974 · 4 eruptions · max VEI 21050 BCE294 BCE46210291785

Detailed timeline

  1. 1974VEI 1Observed
    1974-03-01 – 1974-04-30
    E side of Shinzan, W of Kojin-yama
  2. 1834VEI 2Observed
    1834-07-09 – 1834-07-16
  3. 1821VEI 2Observed
    1821-05-23 – end unknown
    Near Shinzan and Shichiko-zan
  4. 1800VEI 2Observed
    1800-12-16 – 1804-07-16
    Shinzan (foot of Kojin-yama)
  5. 1764VEI 2Method not stated
    1764 – end unknown
  6. 1740VEI 2Observed
    1740-06 – 1747
    Small crater at foot of Kojin-yama
  7. 1738VEI 2Method not stated
    1738-12-31 – end unknown
  8. 1735VEI 2Method not stated
    1735 – end unknown
  9. 1659VEI ?Observed
    1659-04 – 1663
  10. 1560VEI ?Method not stated
    1560 – end unknown
  11. 1477VEI ?Method not stated
    1477 – end unknown
  12. 999VEI ?Method not stated
    999 – end unknown
  13. 948VEI ?Method not stated
    948-12-31 – end unknown
  14. 939VEI ?Observed
    939-05-15 – end unknown
  15. 884VEI ?Method not stated
    884-07-26 – 884-08
  16. 871VEI 2Observed
    871-05-05 – end unknown
  17. 861VEI 3Method not stated
    861-05 – end unknown
  18. 857VEI ?Method not stated
    857-05 – end unknown
  19. 856VEI ?Method not stated
    856 – end unknown
  20. 839VEI ?Method not stated
    839-10-14 – end unknown
  21. 830VEI ?Observed
    830-01 – end unknown
  22. 817 (±7 yrs)VEI ?Observed
    817 – end unknown
  23. 804VEI ?Method not stated
    804 – 806
  24. 717VEI ?Method not stated
    717-07 – end unknown
  25. 711 (±3 yrs)VEI ?Observed
    711 – end unknown
  26. 610 (±18 yrs)VEI ?Method not stated
    610 – end unknown
  27. 577VEI ?Method not stated
    577-12-01 – 578-07-15
  28. 573VEI ?Method not stated
    573-03 – end unknown
  29. 450 BCEVEI ?Geological estimate
    450 BCE – end unknown
  30. 650 BCEVEI ?Geological estimate
    650 BCE – end unknown
    Higashi-Chokai
  31. 1050 BCEVEI 0Geological estimate
    1050 BCE – end unknown
    West flank (Saruana crater)

Nearby volcanoes

External links

⚠ For reference only. Not for emergency response.