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United States · Caldera

Mount Aniakchak

Aniakchak

Type
Caldera
Elevation
1341m
Last eruption
1931
Mount Aniakchak
Photo: M. Williams, National Park Service · Public domain · Wikimedia Commons
Type
Caldera
Country
United States
Region
North America / Alaska Peninsula Volcanic Arc
Elevation
1341m
Coordinates
56.880, -158.170
Last eruption
1931
Tectonic setting
Subduction zone / Continental crust (> 25 km)
Landform
Caldera
Major rock type
Andesite / Basaltic andesite

Geological summary

One of the most dramatic calderas of the Aleutian arc, the 10-km-wide Aniakchak caldera formed around 3,400 years ago during a voluminous eruption in which pyroclastic flows traveled more than 50 km N to the Bering Sea and also reached the Pacific Ocean to the south.

Excerpt from the Global Volcanism Program, Smithsonian Institution · Read the full summary on GVP →

From Wikipedia

Mount Aniakchak is a volcano on the western Alaska Peninsula. Part of the Aleutian Volcanic Arc, it was formed by the subduction of the oceanic Pacific Plate under the North American Plate. Aniakchak is a 10 kilometers (6.2 mi) wide caldera with a break to the northeast. The caldera contains Surprise Lake and many volcanic cones, maars and craters, including Vent Mountain. The volcano has erupted mainly calc-alkaline rocks ranging from basalt to rhyolite.

Wikipedia · CC BY-SA · Read full article →

Eruption history

17 recordedGlossary

Record summary

Confirmed eruptions
16
Uncertain eruptions
1
Span of confirmed record
6300 BCE (±1250 yrs) – 1931
Largest confirmed eruption
VEI 6 (1645 BCE, the most recent of 2)
Confirmed eruptions since 1900
1
Summary (VEI over time)
Click a bar to see individual eruptions · Use arrow keys to move between bars, Enter to open
6300 BCE~6025 BCE · 1 eruptions · max VEI 66025 BCE~5751 BCE · 1 eruptions · max VEI ?2728 BCE~2454 BCE · 1 eruptions · max VEI ?1904 BCE~1630 BCE · 1 eruptions · max VEI 6531 BCE~256 BCE · 1 eruptions · max VEI ?19~294 · 1 eruptions · max VEI ?294~568 · 1 eruptions · max VEI ?568~843 · 1 eruptions · max VEI 0843~1118 · 1 eruptions · max VEI ?1118~1393 · 4 eruptions · max VEI ?1393~1667 · 2 eruptions · max VEI 41667~1942 · 2 eruptions · max VEI 46300 BCE4377 BCE2179 BCE256 BCE1667

Detailed timeline

  1. 1942VEI ?Method not stated
    1942-07-02 – end unknown
  2. 1931VEI 4Observed
    1931-05-01 – 1931-06-13
    West and SW caldera floor
  3. 1540 (±100 yrs)VEI 4Geological estimate
    1540 – end unknown
    NW & S caldera floor (Half Cone, Vent Mtn)
  4. 1470 (±20 yrs)VEI ?Geological estimate
    1470 – end unknown
    SE caldera floor (New Cone)
  5. 1370 (±55 yrs)VEI ?Geological estimate
    1370 – end unknown
    NW caldera floor (Half Cone)
  6. 1280 (±145 yrs)VEI ?Geological estimate
    1280 – end unknown
    NW caldera floor (Half Cone)
  7. 1190 (±30 yrs)VEI ?Geological estimate
    1190 – end unknown
    NW caldera floor (Half Cone)
  8. 1120 (±80 yrs)VEI ?Geological estimate
    1120 – end unknown
    East-central caldera (Surprise Cone)
  9. 1050VEI ?Geological estimate
    1050 – end unknown
    Vent Mtn and other vents?
  10. 700 (±250 yrs)VEI 0Geological estimate
    700 – end unknown
    S & NW caldera floor (Vent Mtn & Half Cone)
  11. 460VEI ?Geological estimate
    460 – end unknown
  12. 200 (±255 yrs)VEI ?Geological estimate
    200 – end unknown
    Northern & western caldera floor
  13. 370 BCE (±210 yrs)VEI ?Geological estimate
    370 BCE – end unknown
  14. 1645 BCE (±10 yrs)VEI 6Geological estimate
    1645 BCE – end unknown
  15. 2550 BCE (±500 yrs)VEI ?Geological estimate
    2550 BCE – end unknown
  16. 5930 BCE (±240 yrs)VEI ?Geological estimate
    5930 BCE – end unknown
  17. 6300 BCE (±1250 yrs)VEI 6Geological estimate
    6300 BCE – end unknown

Nearby volcanoes

External links

⚠ For reference only. Not for emergency response.