Bogoslof


Facts


  • Official Name: Bogoslof Island
  • Seismically Monitored: No
  • Color Code: UNASSIGNED
  • Alert Level: UNASSIGNED
  • Elevation: 150m (492ft)
  • Latitude: 53.9272
  • Longitude: -168.0344
  • Smithsonian VNum: 311300
  • Pronunciation:
  • Nearby Towns:
    • Unalaska 61 mi (98 km) SE
    • Nikolski 76 mi (123 km) SW
    • Akutan 93 mi (149 km) NE
    • Saint George 194 mi (312 km) NW
    • False Pass 197 mi (317 km) NE

    Distance from Anchorage: 835 mi (1344 km)

  • Subfeatures:
    • Fire Island
    • Metcalf Domes
    • McCulloch Peak
    • Tahoma Peak
    • Ship Rock
    • Castle Rock

Description

Bogoslof Island is the largest of a cluster of small, low-lying islands comprising the emergent summit of a large submarine stratovolcano. This stratovolcano rises about 6000 ft (1800 m) from the Bering Sea floor, but is only about 300 ft (100 m) above sea level at its highest point [1] . Bogoslof volcano is unusual in its location. It is slightly north of the main Aleutian volcanic front, and is interpreted as a back-arc feature. This volcano is frequently altered by both eruptions and erosion, and has undergone dramatic changes in historical time.There are currently two islands of this volcano above sea level: Fire Island and Bogoslof Island. Fire Island lies about 2000 ft (610 m) northwest of Bogoslof and is a tiny sea stack. The current-day Fire Island is what remains of a volcano dome extruded in 1883. Bogoslof is triangular in shape, and about 1.2 mi (2 km) by 0.5 mi (0.75 km). On the southwest side of Bogoslof are steep-sided twin pinnacles called Castle Rock - this is what remains of a dome erupted in 1796. On the north end of Bogoslof Island is a small, 500 ft (150 m) by 900 ft (275 m) dome that was erupted in 1992. Other domes erupted at Bogoslof, (which has had confirmed eruptions in 1796-1804, 1806-1823, 1883-1895, 1906, 1907, 1909-1910, 1926-1928, and 1992) have been lost to explosions or erosion [2] [3] [1] .

Name Origin

Quote from Orth (1971): "Bogoslof Island" is a Russian name meaning "theologian," given because the island "rose from the sea May 18, 1796, St. John's Day" (Baker, 1906). The name "O[strov] Ioanna Bogoslova," or "John the Theologian's Island," was published by Lt. Sarichev (1826). Captain Tebenkov (1852) published the name "O[strov] Bogoslova" or "theologian's island".


References Cited

[1] Geology of Umnak and Bogoslof Islands, Aleutian Islands, Alaska, 1959

Byers, F. M. Jr., 1959, Geology of Umnak and Bogoslof Islands, Aleutian Islands, Alaska: in Investigations of Alaskan volcanoes, U.S. Geological Survey Bulletin 1028-L, p. 267-369, 5 sheets, scale 1 at 1:63,360, 1 at 1:96,000, and 1 at 1:300,000.
full-text PDF 3.5 MB
plate 39 PDF 2.2 MB
plate 40 PDF 3.9 MB
plate 41 PDF 5.6 MB
plate 48 PDF 85 KB
table 3 PDF 149 KB

[2] Volcanoes of North America: United States and Canada, 1990

Wood, C. A., and Kienle, Juergen, (eds.), 1990, Volcanoes of North America: United States and Canada: New York, Cambridge University Press, 354 p.

[3] Catalog of the historically active volcanoes of Alaska, 1998

Miller, T. P., McGimsey, R. G., Richter, D. H., Riehle, J. R., Nye, C. J., Yount, M. E., and Dumoulin, J. A., 1998, Catalog of the historically active volcanoes of Alaska: U.S. Geological Survey Open-File Report 98-0582, 104 p.

Current Activity

No new updates for Bogoslof volcano since November 24, 2023, 12:00 pm.

Webicorder

Color Code Timeline

Loading Past Activity...

Loading Images...

Loading Maps...

Loading Bibliography...

Ash Forecasting

Mathematical models developed by the USGS forecast various aspects of how a volcanic ash plume will interact with wind—where, how high, and how fast ash particles will be transported in the atmosphere, as well as where ash will fall out and accumulate on the ground. AVO runs these models when a volcano is restless by assuming a reasonable hypothetical eruption, to provide a pre-eruptive forecast of areas likely to be affected. During an ongoing eruption, AVO will update the forecast with actual observations (eruption start time and duration, plume height) as they become available.

View the current airborne ash cloud models for Bogoslof

Ashfall thickness forecast

The Ash3d model was developed by the USGS to forecast how a volcanic ash plume will interact with wind and where ash will fall out and accumulate on the ground. AVO runs these models twice daily when a volcano is restless by assuming a reasonable hypothetical eruption altitude and duration. The map shows the model results of ashfall thickness for areas that are likely to be affected, if one were to occur. During an ongoing eruption, AVO will update the forecast with actual observations (eruption start time and duration, plume height) as they become available, and these plots will be automatically updated. The National Weather Service Anchorage Forecast Office will issue the official ashfall warning product and post them at weather.gov/afc

THESE PRODUCTS MAY NOT BE CURRENT.

During an actual eruption, see National Weather Service forecasts of ashfall:https://weather.gov/afc.

Ashfall Forecast

Click on the X on the graphic (upper right) to expand the map to show the map legend.

Ashfall Start Time

This map shows the modeled estimate of the time it would take for ashfall to begin following an eruption. It corresponds to the ashfall thickness forecast map shown above. This map uses the start time of either the twice-daily hypothetical model runs (time shown in the legend) or the actual eruption start time (if one were to occur). In the case of an actual eruption, the National Weather Service Anchorage Forecast Office will issue the official ashfall warning product that includes the ashfall start time and post them at weather.gov/afc

THESE PRODUCTS MAY NOT BE CURRENT.

During an actual eruption, see National Weather Service forecasts of ashfall:https://weather.gov/afc.

Ashfall Start Times Forecast

Click on the X on the graphic (upper right) to expand the map to show the map legend.