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Isanotski Peaks

Photo of this volcano
  • United States
  • Aleutian Ridge Volcanic Arc
  • Composite | Stratovolcano
  • Pleistocene
  • Country
  • Volcanic Province
  • Landform | Volc Type
  • Last Known Eruption
  • 54.765°N
  • 163.723°W

  • 2446 m
    8025 ft

  • 311370
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports available for Isanotski Peaks.

The Global Volcanism Program has no Weekly Reports available for Isanotski Peaks.

The Global Volcanism Program has no Bulletin Reports available for Isanotski Peaks.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

The Global Volcanism Program is not aware of any Holocene eruptions from Isanotski Peaks. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the Isanotski Peaks page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

Deformation History

There is no Deformation History data available for Isanotski Peaks.

Emission History

There is no Emissions History data available for Isanotski Peaks.

Photo Gallery

Despite its extensive glacial cover, Shishaldin volcano maintains its symmetrical profile because of frequent eruptions. Aa lava flows, erupted from summit and satellitic vents, spread over the NW flank, the location of more than 2 dozen pyroclastic cones. The dominantly basaltic volcano is the highest peak in the Aleutian Islands. The rugged, dissected Isanotski volcano rises to the east behind Shishaldin.

Copyrighted photo by Katia and Maurice Krafft, 1978.
The effects of differential erosion are dramatically seen in this aerial view of two Alaskan volcanoes. Isanotski volcano in the foreground, sometimes referred to as "Ragged Jack," has been extensively dissected by glaciers that have excavated steep walls separated by narrow ridges. The symmetrical Shishaldin volcano in the background is sometimes referred to as the Mount Fuji of the Aleutians. In contrast to Isanotski, Shishaldin is one of Alaska's most active volcanoes. Frequent eruptions maintain the young, constructional profile of the volcano.

Copyrighted photo by Katia and Maurice Krafft, 1978.
Isanotski volcano, sometimes referred to as "Ragged Jack," has been extensively dissected by glaciers. Although historical eruptions in the 18th and 19th centuries have been attributed to Isanotski, these reports from an infrequently visited region with notoriously poor weather must be considered somewhat suspect.

Copyrighted photo by Katia and Maurice Krafft, 1978.
Three volcanoes are constructed along an E-W trend on the eastern half of Unimak Island. Roundtop in the foreground is glacially eroded and has Holocene pyroclastic flow deposits and a group of lava domes to the south. Isanotski is in the background and Shishaldin is in the midground.

Photo by Clayton and Marcia Brown, 1986 (courtesy of John Reeder, Alaska Div. Geology Geophysical Surveys).
Unimak Island has three volcanoes constructed along an E-W line. Shishaldin is in the foreground and is the highest of the three in this 1987 photo. Isanotski is to the right and Roundtop is in the far distance.

Photo by Clayton and Marcia Brown, 1987 (courtesy of John Reeder, Alaska Div. Geology & Geophysical Surveys).
Glaciers descend the upper flanks of Isanotski between the summit pinnacles. Locally known as Ragged Jack, this is at the center of an E-W-trending group of three volcanoes on Unimak Island.

Photo courtesy of Alaska Volcano Observatory, 1994.
GVP Map Holdings

Maps are not currently available due to technical issues.

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.

Smithsonian Sample Collections Database

There are no samples for Isanotski Peaks in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites