Fisher


Facts


  • Official Name: Fisher Caldera
  • Seismically Monitored: Yes
  • Color Code: GREEN
  • Alert Level: NORMAL
  • Elevation: 1112m (3648ft)
  • Latitude: 54.6692
  • Longitude: -164.3524
  • Smithsonian VNum: 311350
  • Pronunciation:
  • Nearby Towns:
    • False Pass 40 mi (64 km) NE
    • Pauloff Harbor 68 mi (109 km) SE
    • Akutan 68 mi (109 km) SW
    • Cold Bay 74 mi (119 km) NE
    • King Cove 86 mi (138 km) NE

    Distance from Anchorage: 694 mi (1117 km)

  • Subfeatures:
    • Eickelberg Peak (Cone 8)
    • Finch, Mt
    • Nick's cone
    • Pyro Hill
    • Turquoise cone
    • Neptune

Description

From Miller and others (1998): "Fisher caldera is 11 km wide by 18 km long, and has a maximum internal relief of 929 m. It is one of at least three volcanoes on Unimak Island that have been active in historical time.
"The caldera is remarkable in size - one of the largest calderas in the Aleutian arc - and for the mobility of the ash flows that resulted from the caldera-forming eruption about 9100 years ago (Miller and Smith, 1977; 1987). The ash flows reached the Pacific Ocean 8 km to the southeast, and swept part way up the slopes of stratovolcanoes to the east and southwest. To the north, ash flows crossed 15 km of lowland to reach the Tugamak Range, surmounted drainage divides as much as 400 m above the lowland surface in the range, and continued northward an additional 8 km to the Bering Sea coastline. Miller and Smith (1977) inferred that the ash flows had unusually high velocities to cross such topographic barriers and suggested that the high velocities resulted by ash fall-back from a high eruption column.
"Fisher caldera was the location of a large andesitic stratovolcano that was largely destroyed during caldera formation. Very little study has been done on the caldera itself. Post-caldera activity of Fisher caldera appears to consist of dome emplacement and eruption of lava flows and associated pyroclastic material, some of which may be historical in age (Miller and Smith, 1977)."

Name Origin

Fisher Caldera was named for Bernard Fisher of the U.S. Geological Survey, who lost his life in Umnak Pass while investigating the volcanic geology of the Aleutian Islands (U.S. Geographic Names Informaion System, accessed January 14, 2009.


Current Activity

No new updates for Fisher volcano since May 13, 2024, 3:43 pm.

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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 Fisher

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.