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Augustine Volcano

Augustine

Lava dome · United States · 1218m

Augustine in Kamishak Bay in the southern Cook Inlet is the most active volcano of the eastern Aleutian arc. It consists of a complex of overlapping summit lava domes surrounded by an apron of volcaniclastic deposits that descend to the sea on all sides. This 1986 view from the NW shows Augustine reflected in a shallow lagoon separating the small west island from the main island. Twentieth-century eruptions have included explosive activity with pyroclastic flows and lava dome growth.
Augustine in Kamishak Bay in the southern Cook Inlet is the most active volcano of the eastern Aleutian arc. It consists of a complex of overlapping summit lava domes surrounded by an apron of volcaniclastic deposits that descend to the sea on all sides. This 1986 view from the NW shows Augustine reflected in a shallow lagoon separating the small west island from the main island. Twentieth-century eruptions have included explosive activity with pyroclastic flows and lava dome growth. · Photo: Photo by Lee Siebert, 1986 (Smithsonian Institution). · Wikimedia Commons
Type
Lava dome
Country
United States
Region
North America Volcanic Regions / Alaska Peninsula Volcanic Arc
Elevation
1218m
Coordinates
59.363, -153.435
Last eruption
2006
Tectonic setting
Subduction zone / Continental crust (> 25 km)
Landform
Composite
Major rock type
Andesite / Basaltic Andesite
Geological summary

Augustine volcano, rising above Kamishak Bay in the southern Cook Inlet about 290 km SW of Anchorage, is the most active volcano of the eastern Aleutian arc. It consists of a complex of overlapping summit lava domes surrounded by an apron of volcaniclastic debris that descends to the sea on all sides. Few lava flows are exposed; the flanks consist mainly of debris-avalanche and pyroclastic-flow deposits formed by repeated collapse and regrowth of the summit. The latest episode of edifice collapse occurred during Augustine's large 1883 eruption; subsequent dome growth has restored the edifice to a height comparable to that prior to 1883. The oldest dated volcanic rocks on Augustine are more than 40,000 years old. At least 11 large debris avalanches have reached the sea during the past 1,800-2,000 years, and five major pumiceous tephras have been erupted during this interval. Recorded eruptions have typically consisted of explosive activity with emplacement of pumiceous pyroclastic-flow deposits followed by lava dome extrusion with associated block-and-ash flows.

From Wikipedia

Augustine Volcano is a stratovolcano in Alaska consisting of a central complex of summit lava domes and flows surrounded by an apron of pyroclastic, lahar, avalanche, and ash deposits. The volcano forms Augustine Island, colloquially called Mount St. Augustine, in southwestern Cook Inlet in the Kenai Peninsula Borough of southcentral coastal Alaska, about 70 miles (113 km) west of Homer and about 175 miles (282 km) southwest of Anchorage.

Wikipedia · CC BY-SA · Read full article →

Eruption history

Summary (VEI over time)
Click a bar to see individual eruptions
5420 BCE~5172 BCE · 1 eruptions · max VEI ?4182 BCE~3935 BCE · 1 eruptions · max VEI ?2202 BCE~1955 BCE · 1 eruptions · max VEI ?1955 BCE~1707 BCE · 1 eruptions · max VEI ?470 BCE~222 BCE · 2 eruptions · max VEI ?222 BCE~25 · 1 eruptions · max VEI ?273~520 · 1 eruptions · max VEI ?520~768 · 1 eruptions · max VEI ?768~1015 · 1 eruptions · max VEI ?1015~1263 · 1 eruptions · max VEI ?1510~1758 · 2 eruptions · max VEI 41758~2005 · 9 eruptions · max VEI 45420 BCE3687 BCE1707 BCE251758

Detailed timeline

  1. 2005VEI 3Observed
    2005-12-09 – 2006-04-27
  2. 1986VEI 4Observed
    1986-03-27 – 1986-08-31
  3. 1976VEI 4Observed
    1976-01-22 – 1977-05-14
  4. 1971VEI 1Observed
    1971-10-07 – 1971-10-08
  5. 1963VEI 2Observed
    1963-10-11 – 1964-08-19
  6. 1935VEI 3Observed
    1935-03-13 – 1935-08-18
  7. 1908VEI 1Observed
    1908 – Ongoing
  8. 1883VEI 4Observed
    1883-10-06 – 1884
  9. 1812VEI 3Observed
    1812 – Ongoing
  10. 1650 (±100 yrs)VEI ?Geological estimate
    1650 – Ongoing
  11. 1540 (±100 yrs)VEI 4Geological estimate
    1540 – Ongoing
  12. 1230 (±50 yrs)VEI ?Geological estimate
    1230 – Ongoing
  13. 930 (±150 yrs)VEI ?Geological estimate
    930 – Ongoing
  14. 570 (±150 yrs)VEI ?Geological estimate
    570 – Ongoing
  15. 340 (±40 yrs)VEI ?Geological estimate
    340 – Ongoing
  16. 120 BCE (±40 yrs)VEI ?Geological estimate
    BCE 120 – Ongoing
  17. 310 BCE (±100 yrs)VEI ?Geological estimate
    BCE 310 – Ongoing
  18. 350 BCE (±200 yrs)VEI ?Geological estimate
    BCE 350 – Ongoing
  19. 1820 BCE (±300 yrs)VEI ?Geological estimate
    BCE 1820 – Ongoing
  20. 2040 BCE (±300 yrs)VEI ?Geological estimate
    BCE 2040 – Ongoing
  21. 4150 BCE (±100 yrs)VEI ?Geological estimate
    BCE 4150 – Ongoing
  22. 5420 BCE (±50 yrs)VEI ?Geological estimate
    BCE 5420 – Ongoing

External links

⚠ For reference only. Not for emergency response.