Logo link to homepage

Isanotski

Photo of this volcano
  • United States
  • Alaska
  • Stratovolcano
  • Unknown - Evidence Uncertain
  • Country
  • Volcanic Region
  • Primary Volcano 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 for Isanotski.

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

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

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

There is data available for 5 Holocene eruptive periods.

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1845 ] [ Unknown ] Uncertain    
[ 1831 Mar ] [ 1831 May 6 ± 1 days ] Uncertain    
[ 1830 Nov ] [ Unknown ] Uncertain 2  
[ 1825 Mar 10 ] [ Unknown ] Uncertain 4  
[ 1795 ] [ Unknown ] Uncertain 3  
Deformation History

There is no Deformation History data available for Isanotski.

Emission History

There is no Emissions History data available for Isanotski.

Photo Gallery

Three prominent volcanoes are constructed along an E-W line on the eastern half of Unimak Island. The aptly named Roundtop volcano in the lower foreground is glacially eroded and has had no historical eruptive activity. In the 1930s warm springs were found on its slopes. The recent discovery of Holocene pyroclastic-flow deposits and a group of lava domes south of Roundtop indicate it is still an active volcano. The glacially dissected Isanotski volcano and the beautifully symmetrical Shishaldin volcano are the prominent peaks behind Roundtop.

Photo by Clayton and Marcia Brown, 1986 (courtesy of John Reeder, Alaska Div. Geology Geophysical Surveys).
See title for photo information.
Three prominent stratovolcanoes are constructed along an E-W line on Unimak Island. Steaming Shishaldin, the highest of the three, rises to 2857 m in the foreground and is one of the most active volcanoes in the Aleutians. The dissected Isanotski volcano (right) has had reported eruptions of uncertain validity, and Roundtop volcano (center distance) has had Holocene eruptions, but no historical activity.

Photo by Clayton and Marcia Brown, 1987 (courtesy of John Reeder, Alaska Div. Geology & Geophysical Surveys).
See title for photo information.
Glaciers drape the ruggedly dissected upper flanks of Isanotski volcano and its dramatic summit pinnacles. Isanotski, locally known as Ragged Jack, is at the center of an E-W-trending group of three volcanoes on Unimak Island. Four poorly documented historical eruptions were noted in the 18th and 19th centuries. Some or all of these eruptions, however, could have been from neighboring Shishaldin volcano, and historical eruptions of Isanotski must be considered unlikely, given the extreme degree of erosional dissection.

Photo courtesy of Alaska Volcano Observatory, 1994.
See title for photo information.
GVP Map Holdings

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. The maps database originated over 30 years ago, but was only recently updated and connected to our main database. We welcome users to tell us if they see incorrect information or other problems with the maps; please use the Contact GVP link at the bottom of the page to send us email.

Title: Dutch Harbor
Publisher: US Department of Commerce, NOAA National Ocean Service
Country: United States
Year: 1987
Series: Section Aero Chart
Map Type: Navigation
Scale: 1:500,000
Map of Dutch Harbor
Title: Cold Bay
Publisher: US Department of Commerce, NOAA National Ocean Service
Country: United States
Year: 1987
Series: Sectional Aero Chart
Map Type: Topographic
Scale: 1:500,000
Map of Cold Bay
Title: United States
Publisher: DMA Aerospace Center
Country: United States
Year: 1987
Series: ONC
Map Type: Topographic
Scale: 1:1,000,000
Map of United States
Title: Map Showing Distribution, Composition, and Age of Late Cenozoic Volcanic Craters in Alaska
Publisher: US Geological Survey
Country: United States
Year: 1986
Series: Misc Investigations
Map Type: Geology
Scale: 1:1,000,000
Map of Map Showing Distribution, Composition, and Age of Late Cenozoic Volcanic Craters in Alaska
Title: Saint George Basin Regional Map
Publisher: USDI Minerals Management Service
Country: United States
Year: 1984
Series: OCSRM maps
Map Type: Bathymetric
Scale: 1:1,000,000
Map of Saint George Basin Regional Map
Title: N Aleutian Basin, Gulf of AK
Publisher: USDI Minerals Management Service
Country: United States
Year: 1984
Series: OCSRM maps
Map Type: Bathymetric
Scale: 1:1,000,000
Map of N Aleutian Basin, Gulf of AK
Title: False Pass
Publisher: US Department of Commerce, NOAA National Ocean Service
Country: United States
Year: 1984
Map Type: Bathymetric
Scale: 1:250,000
Map of False Pass
Title: N Pacific Ocean, NOS Seamount Series
Publisher: US Department of Commerce, NOAA National Ocean Service
Country: United States
Year: 1973
Map Type: Bathymetric
Scale: 1:1,000,000
Map of N Pacific Ocean, NOS Seamount Series
Title: Magnetic Map of N Pacific Ocean
Publisher: US Department of Commerce, NOAA National Ocean Service
Country: United States
Year: 1973
Series: Seamap
Map Type: Geophysical (Magnetic)
Scale: 1:1,000,000
Map of Magnetic Map of N Pacific Ocean
Title: Gravity Map of N Pacific Ocean
Publisher: US Department of Commerce, NOAA National Ocean Service
Country: United States
Year: 1973
Series: Seamap
Map Type: Geophysical (Gravity)
Scale: 1:1,000,000
Map of Gravity Map of N Pacific Ocean
Title: Unimak
Publisher: US Geological Survey
Country: United States
Year: 1966
Series: AK Recon Topo 250
Map Type: Topographic
Scale: 1:250,000
Map of Unimak
Title: False Pass
Publisher: US Geological Survey
Country: United States
Year: 1956
Series: AK Recon Topo 250
Map Type: Topographic
Scale: 1:250,000
Map of False Pass
Title: Fort Randall
Publisher: US Geological Survey
Country: United States
Year: 1943
Series: AK Recon Topo 250
Map Type: Geographic
Scale: 1:250,000
Map of Fort Randall
Smithsonian Sample Collections Database

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

Affiliated Sites