Data from the Global Volcanism Program of the Smithsonian Institution
Details for: Semisopochnoi
The western slopes of symmetrical Sugarloaf Peak (left) rise above tundra-covered Semisopochnoi Island. Semisopochnoi, the largest subaerial volcano of the western Aleutians, is 20 km wide at sea level and contains an 8-km-wide caldera. Three-peaked Mount Cerberus volcano was constructed within the caldera during the Holocene, along with symmetrical Sugarloaf Peak volcano outside of the caldera to the SSE. Most documented historical eruptions have originated from Cerberus. Photo by Steve Ebbert, 1997 (U.S. Fish and Wildlife Service).
Volcano Number:311060
Volcano Name:Semisopochnoi
Country:United States
Volcano Type:Stratovolcano
Last Eruption:2018
Elevation:1221m
Tectonic Setting:Subduction zone / Intermediate crust (15-25 km)
Pop. within 5km:0
Pop. within 10km:0
Pop. within 30km:0
Pop. within 100km:0
Latitude:51.93
Longitude:179.58



Eruption Data from the Global Volcanism Program of the Smithsonian Institution
Volcano Number Volcano Name Eruption Number Activity Type Explosivity Index Max Explosivity Index Modifier Activity Area Activity Unit Start Evidence Method Start Date End Date
311060 Semisopochnoi 19568 Uncertain Eruption Cerberus 1792
311060 Semisopochnoi 19569 Uncertain Eruption Cerberus 1830
311060 Semisopochnoi 19670 Uncertain Eruption Cerberus 1772
311060 Semisopochnoi 19671 Uncertain Eruption Cerberus 1790
311060 Semisopochnoi 19672 Confirmed Eruption Cerberus Historical Observations 1873
311060 Semisopochnoi 19673 Confirmed Eruption 2 ? Sugarloaf ? Historical Observations 1987/4/13
311060 Semisopochnoi 22289 Confirmed Eruption 1 Historical Observations 2018/9/8 2018/10/31
Emissions Data from the Global Volcanism Program of the Smithsonian Institution No emissions data found for this volcano.


Data from the Earthchem Portal


Data from the SESAR Database


Data from the MaGa Database
Sorry. No data exist for this volcano in the MaGa database.