Global Volcanism Program

The Global Volcanism Program has no activity reports available for Yunaska.

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

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

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude

311210

1937 CE

550 m / 1,804 ft

52.6394°N
170.6317°W

Morphology

Volcano Landform
Shield

Volcano Types
Shield
Caldera(s)
Pyroclastic cone(s)

Rock Types

Major
Andesite / Basaltic Andesite
Basalt / Picro-Basalt
Dacite

Tectonic Setting

Subduction zone
Intermediate crust (15-25 km)

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km

0
0
0
0

Geological Summary

The elongated 9 x 23 km Yunaska in the Islands of the Four Mountains group of the Aleutian Islands is comprised of two distinct volcanic centers. The older western center consists of the eroded remnants of four overlapping stratovolcanoes that form a linear, NNE-trending ridge. Cinder cones and fissure-fed lava flows extend from the western end of the complex. The younger eastern complex consists of a shield volcano capped by two nested calderas. The 3.5-km-wide Coats caldera is located within an older 10 x 13 km caldera and contains cinder cones and a lava field. Two areas of youthful lava flows extend down the flank through a gap in the SW caldera rim and cover the upper N flank of the caldera. Vents are found on the flanks of the caldera within a kilometer of its rim. A post-caldera cone is capped by a small summit crater. The eastern center is presumably the source of eruptions recorded since the early 1800s.

This volcano is located within the Aleutian Islands, a UNESCO Biosphere Reserve property.

References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

Coats R R, 1950. Volcanic activity in the Aleutian Arc. U S Geol Surv Bull, 974-B: 35-47.

Henning R A, Rosenthal C H, Olds B, Reading E (eds), 1976. Alaska's volcanoes, northern link in the ring of fire. Alaska Geog, 4: 1-88.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior.

Lamb D, Linneman S R, Myers J D, Nicolaysen K E, 1992. Caldera formation on Yunaska Island, central Aleutian arc (abs). Eos, Trans Amer Geophys Union, 73: 645.

Miller T P, McGimsey R G, Richter D H, Riehle J R, Nye C J, Yount M E, Dumoulin J A, 1998. Catalogue of the historically active volcanoes of Alaska. U S Geol Surv Open-File Rpt, 98-582: 1-104.

Motyka R J, Liss S A, Nye C J, Moorman M A, 1993. Geothermal resources of the Aleutian arc. Alaska Div Geol Geophys Surv, Prof Rpt, no 114, 17 p and 4 map sheets.

Myers J D, 1994. The Geology, Geochemistry and Petrology of the recent Magmatic Phase of the Central and Western Aleutian Arc. Unpublished manuscript, unpaginated.

Nicolaysen K E, Myers J D, Linneman S R, Lamb D, 1992. Geologic relations of the Yunaska volcanic complex, central Aleutian arc (abs). Eos, Trans Amer Geophys Union, 73: 645.

Smith R L, Shaw H R, Luedke R G, Russell S L, 1978. Comprehensive tables giving physical data and thermal energy estimates for young igneous systems of the United States. U S Geol Surv Open-File Rpt, 78-925: 1-25.

Wood C A, Kienle J (eds), 1990. Volcanoes of North America. Cambridge, England: Cambridge Univ Press, 354 p.

Eruptive History

There is data available for 3 confirmed Holocene eruptive periods.

1937 Nov 3 - 1937 Nov 4 Confirmed Eruption (Explosive / Effusive) VEI: 3

Episode 1 | Eruption (Explosive / Effusive)

1937 Nov 3 - 1937 Nov 4

Evidence from Observations: Reported

Coats (1950) reported a major explosive eruption on 3-4 November 1937. Hantke (1939a) noted press reports of a devastating eruption with ashfall and a lava flow. A violent eruption with "flames" originating near the center of the island was reported by a passing ship (Miller et al., 1998).

List of 4 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Explosion
- - - -	- - - -	Lava flow	Uncertain
- - - -	- - - -	Flames
1937 Nov 3	- - - -	VEI (Explosivity Index)

[ 1929 ] Uncertain Eruption

Episode 1 | Uncertain

1929 - Unknown

Evidence from Unknown

"Smoke" was reported in 1929 (Powers, 1958).

List of 1 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Volcanic "smoke"

[ 1873 ] Uncertain Eruption

Episode 1 | Uncertain

1873 - Unknown

Evidence from Unknown

Decker (1971) lists an eruption in 1873, apparently originating from Becker's (1898) report that Yunaska steamed in 1873.

List of 1 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	1873	- - - -	VEI (Explosivity Index)

1830 Confirmed Eruption (Explosive / Effusive) VEI: 2

Episode 1 | Eruption (Explosive / Effusive)

1830 - Unknown

Evidence from Observations: Reported

Minor ash emission took place in 1830 (Coats, 1950).

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Explosion	weak or small
- - - -	- - - -	Ash	weak or small
1830	- - - -	VEI (Explosivity Index)

1824 Confirmed Eruption (Explosive / Effusive) VEI: 3

Episode 1 | Eruption (Explosive / Effusive)

1824 - Unknown

Evidence from Observations: Reported

A major explosive eruption took place in 1824 (Coats, 1950).

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Explosion
	1824	- - - -	VEI (Explosivity Index)

[ 1817 ] Uncertain Eruption

Episode 1 | Uncertain

1817 - Unknown

Evidence from Unknown

Reports of "smoke" may have been vapor condensation clouds (Coats, 1950).

List of 1 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Volcanic "smoke"

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.

Craters

Feature Name

Feature Type

Elevation

Latitude

Longitude

Coats Caldera

Caldera

Photo Gallery

The summit caldera rim of Yunaska is seen from an older volcanic center on the western side of the island. The younger eastern complex contains two nested calderas. A young lava flow to the far right descended through a notch in the caldera rim. The peaks in the background are (left-to-right) of Carlisle, Cleveland, and Herbert volcanoes.

Photo by Jim Meyers, 1992 (University of Wyoming, courtesy of Alaska Volcano Observatory).

Smithsonian Sample Collections Database

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

External Sites

Alaska Volcano Observatory (Link to Yunaska)

The Alaska Volcano Observatory (AVO) is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO was formed in 1988, and uses federal, state, and university resources to monitor and study Alaska's hazardous volcanoes, to predict and record eruptive activity, and to mitigate volcanic hazards to life and property.

Copernicus Browser

The Copernicus Browser replaced the Sentinel Hub Playground browser in 2023, to provide access to Earth observation archives from the Copernicus Data Space Ecosystem, the main distribution platform for data from the EU Copernicus missions.

MIROVA

Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity.

MODVOLC Thermal Alerts

Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales.

WOVOdat
   Single Volcano View
   Temporal Evolution of Unrest
   Side by Side Volcanoes

WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.

GVMID Data on Volcano Monitoring Infrastructure The Global Volcano Monitoring Infrastructure Database GVMID, is aimed at documenting and improving capabilities of volcano monitoring from the ground and space. GVMID should provide a snapshot and baseline view of the techniques and instrumentation that are in place at various volcanoes, which can be use by volcano observatories as reference to setup new monitoring system or improving networks at a specific volcano. These data will allow identification of what monitoring gaps exist, which can be then targeted by remote sensing infrastructure and future instrument deployments.

Volcanic Hazard Maps

The IAVCEI Commission on Volcanic Hazards and Risk has a Volcanic Hazard Maps database designed to serve as a resource for hazard mappers (or other interested parties) to explore how common issues in hazard map development have been addressed at different volcanoes, in different countries, for different hazards, and for different intended audiences. In addition to the comprehensive, searchable Volcanic Hazard Maps Database, this website contains information about diversity of volcanic hazard maps, illustrated using examples from the database. This site is for educational purposes related to volcanic hazard maps. Hazard maps found on this website should not be used for emergency purposes. For the most recent, official hazard map for a particular volcano, please seek out the proper institutional authorities on the matter.

IRIS seismic stations/networks

Incorporated Research Institutions for Seismology (IRIS) Data Services map showing the location of seismic stations from all available networks (permanent or temporary) within a radius of 0.18° (about 20 km at mid-latitudes) from the given location of Yunaska. Users can customize a variety of filters and options in the left panel. Note that if there are no stations are known the map will default to show the entire world with a "No data matched request" error notice.

UNAVCO GPS/GNSS stations

Geodetic Data Services map from UNAVCO showing the location of GPS/GNSS stations from all available networks (permanent or temporary) within a radius of 20 km from the given location of Yunaska. Users can customize the data search based on station or network names, location, and time window. Requires Adobe Flash Player.

DECADE Data

The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the Mapping Gas Emissions (MaGa) Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO₂ to the atmosphere, but installing CO₂ monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere.

Large Eruptions of Yunaska

Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

EarthChem

EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).