Edgecumbe


Facts


  • Official Name: Mount Edgecumbe
  • Seismically Monitored: Yes
  • Color Code: GREEN
  • Alert Level: NORMAL
  • Elevation: 976m (3202ft)
  • Latitude: 57.0509
  • Longitude: -135.7611
  • Smithsonian VNum: 315040
  • Pronunciation:
  • Nearby Towns:
    • Sitka 16 mi (26 km) NE
    • Tenakee Springs 54 mi (87 km) NE
    • Angoon 54 mi (87 km) NE
    • Pelican 65 mi (105 km) NW
    • Kake 68 mi (110 km) SE

    Distance from Anchorage: 576 mi (928 km)

  • Subfeatures:
    • Crater Ridge
    • Shell Mtn

Description

From Wood and Kienle (1990) [1] : "The Edgecumbe volcanic field on southern Kruzof Island is on the North American plate 10-15 km inboard of the Queen Charlotte-Fairweather transform fault. The Edgecumbe volcanic field is dominated by the symmetric stratovolcano of Mount Edgecumbe and the domes and crater of adjacent Crater Ridge. Mount Edgecumbe was named by Captain James Cook in 1778. The basal shield comprises ~35 cubic km and consists of basalt, basaltic andesite, and andesite lava flows and breccias. The composite cone of Mount Edgecumbe is dominantly of andesite composition and has a volume of ~3.5 cubic km. The low-silica rhyolite domes of Crater Ridge also contain ~3.5 cubic km of magma.
"The latest significant eruptive activity was postglacial and produced voluminous pyroclastic deposits (7.6 cubic km dense-rock equivalent). The main geomorphic features of the Edgecumbe volcanic field were formed during this activity and include basaltic andesite scoria cones, a crater explosively reamed from the Crater Ridge domes during eruptions of rhyolitic pyroclastic flows, and eruption of andesite and dacite tephra during dome emplacement and crater formation on the Mount Edgecumbe cone. Tephra deposits produced by the late Pleistocene-early Holocene activity of the Edgecumbe volcanic field have been found as far away as Juneau and Lituya Bay, 200 km to the north. Vents active during the pyroclastic eruptions have a northeast-southwest alignment that probably marks a regional fissure."

Name Origin

Mount Edgecumbe was named in 1778 by Captain James Cook, "probably after Mt. Edgecumbe at the entrance of Plymouth Harbor, England, or possibly after George, the first Earl of Edgecumbe. The name was adopted by Vancouver" (Wagner, 1937). This feature was also called "Montana de San Jacinto," or "Saint Jacinto Mountain," on August 16, 1775, by Don Juan de la Bodega y Quadra, "in honor of the saint whose day it was" (Wagner, 1937). Lt. Sarychev (1826) called it "Gora Svataya Lazarya," or "Saint Lazarus Mountain (Orth, 1971).


References Cited

[1] 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.

Current Activity

No new updates for Edgecumbe volcano since February 9, 2024, 10:57 am.

Webcams

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 Edgecumbe

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.