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Mount Iwaki

Iwakisan

Stratovolcano · Japan · 1624m

Iwakisan rises above farmlands below its SE flank. The peak to the left is Chokaisan and the 2-km-wide summit crater is filled by a lava dome that forms the summit. Eruptions have occurred since 1597 CE and have consisted primarily of small-to-moderate phreatic explosions.
Iwakisan rises above farmlands below its SE flank. The peak to the left is Chokaisan and the 2-km-wide summit crater is filled by a lava dome that forms the summit. Eruptions have occurred since 1597 CE and have consisted primarily of small-to-moderate phreatic explosions. · Photo: Copyrighted photo by Yoshihiro Ishizuka (Japanese Quaternary Volcanoes database, RIODB, http://riodb02.ibase.aist.go.jp/strata/VOL_JP/EN/index.htm and Geol Surv Japan, AIST, http://www.gsj.jp/). · Wikimedia Commons
Type
Stratovolcano
Country
Japan
Region
Northwestern Pacific / Northeast Japan Volcanic Arc
Elevation
1624m
Coordinates
40.656, 140.303
Last eruption
1863
Tectonic setting
Subduction zone / Continental crust (> 25 km)
Landform
Composite
Major rock type
Andesite / Basaltic Andesite
Geological summary

Iwakisan volcano, symmetrical on all but its western flanks, has a 2-km-wide summit crater filled by a lava dome flanked by six explosion craters. Three more lava domes are found on the western and southern flanks of the andesitic volcano. Eruptions have been reported since 1600 CE, consisting primarily of small-to-moderate phreatic explosions.

Eruption history

Summary (VEI over time)
Click a bar to see individual eruptions
8050 BCE~7720 BCE · 1 eruptions · max VEI ?4085 BCE~3754 BCE · 1 eruptions · max VEI ?1111 BCE~780 BCE · 1 eruptions · max VEI ?780 BCE~450 BCE · 1 eruptions · max VEI ?1533~1863 · 25 eruptions · max VEI 38050 BCE5737 BCE3093 BCE780 BCE1533

Detailed timeline

  1. 1863VEI 1Observed
    1863-03-23 – Ongoing
  2. 1856VEI 2Geological estimate
    1856-05-20 – Ongoing
  3. 1848VEI 2Geological estimate
    1848-01-18 – Ongoing
  4. 1845VEI 2Observed
    1845-04-04 – Ongoing
  5. 1844VEI 2Observed
    1844-04-07 – Ongoing
    Summit and south flank?
  6. 1833VEI 2Geological estimate
    1833-04-11 – Ongoing
  7. 1807VEI 2Geological estimate
    1807-03-31 – Ongoing
  8. 1800VEI 2Geological estimate
    1800-05-11 – Ongoing
  9. 1794VEI 2Geological estimate
    1794-04-03 – Ongoing
  10. 1793VEI 2Geological estimate
    1793-04-02 – Ongoing
  11. 1790VEI 2Observed
    1790-10-09 – Ongoing
  12. 1783VEI 2Geological estimate
    1783-12-03 – Ongoing
  13. 1782VEI 2Geological estimate
    1782-04-12 – Ongoing
    South flank
  14. 1782VEI 2Observed
    1782-12-01 – 1783-03-12
  15. 1769VEI 2Geological estimate
    1769 – Ongoing
  16. 1709VEI 2Geological estimate
    1709-04-23 – Ongoing
  17. 1694VEI 2Geological estimate
    1694-06-19 – Ongoing
  18. 1672VEI 2Geological estimate
    1672-07-12 – 1672-07-28
  19. 1618VEI 2Observed
    1618-01-31 – Ongoing
  20. 1605VEI 2Geological estimate
    1605-04-10 – Ongoing
  21. 1604VEI 3Observed
    1604-02-07 – Ongoing
    Torinoumi
  22. 1600VEI 2Observed
    1600-02-22 – Ongoing
    Torinoumi
  23. 1600VEI 2Observed
    1600-07-23 – 1600-07-25
    Torinoumi
  24. 1597VEI 2Geological estimate
    1597-01 – Ongoing
  25. 1597VEI 2Geological estimate
    1597-06-13 – Ongoing
  26. 550 BCE (±500 yrs)VEI ?Geological estimate
    BCE 550 – Ongoing
    Torinoumi lava dome
  27. 1050 BCEVEI ?Geological estimate
    BCE 1050 – Ongoing
    Summit and central lava dome
  28. 4050 BCEVEI ?Geological estimate
    BCE 4050 – Ongoing
    West summit lava dome
  29. 8050 BCEVEI ?Geological estimate
    BCE 8050 – Ongoing
    Torinoumi lava dome

External links

⚠ For reference only. Not for emergency response.