Global Volcanism Program

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

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

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

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.

Synonyms

Mckenzie Highway Lava Field

Cones

Feature Name

Feature Type

Elevation

Latitude

Longitude

Innaccesible Cones

Pyroclastic cone

1435 m

44° 18' 11" N

121° 54' 23" W

Little Belknap

Shield volcano

1921 m

44° 16' 59" N

121° 49' 31" W

South Belknap

Pyroclastic cone

1784 m

44° 16' 3" N

121° 50' 41" W

Twin Craters

Pyroclastic cone

1609 m

44° 15' 14" N

121° 53' 6" W

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude

322060

475 CE

2,094 m / 6,870 ft

44.285°N
121.8423°W

Morphology

Volcano Landform
Shield

Volcano Types
Shield(s)
Pyroclastic cone(s)

Rock Types

Major
Andesite / Basaltic Andesite
Basalt / Picro-Basalt

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Population

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

0
0
6,518
362,091

Geological Summary

The Belknap Crater area near McKenzie Pass in Oregon, north of the Three Sisters volcanoes, was the source of one of the largest concentrations of youthful volcanism in the Cascade Range. The basaltic to basaltic-andesite Belknap shield volcano, topped by the Belknap Crater pyroclastic cone and the Little Belknap shield volcano immediately to the east, have produced widespread late Holocene lava flows on all sides, much of which took place between about 3,000 and 1,500 years ago. Eruptions from the NE base of Belknap crater produced lava flows that traveled 15 km W into the McKenzie River valley.

References

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

Green J, Short N M, 1971. Volcanic Landforms and Surface Features: a Photographic Atlas and Glossary. New York: Springer-Verlag, 519 p.

Hildreth W E, 2007. Quaternary magmatism in the Cascades--geologic perpectives. U S Geol Surv Prof Pap, 1744: 1-125.

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

Peterson N V, Groh E A, 1963. Recent volcanic landforms in central Oregon. Ore Bin, 25: 1-15.

Peterson N V, Groh E A, 1966. Lunar Geological Field Conference guidebook. Oregon Dept Geol Min Ind, 51 p.

Sherrod D R, Taylor E M, Ferns M L, Scott W E, Conrey R M, Smith G A, 2004. Geologic map of the Bend 30- x 60-minute quadrangle, central Oregon. U S Geol Surv Map , I-2683, 1:100,000 scale and 48 p text.

Taylor E M, 1965. Recent volcanism between Three Fingered Jack and North Sister Oregon Cascade Range. Ore Bin, 27: 121-148.

Taylor E M, 1968. Roadside geology, Santiam and McKenzie Pass Highways, Oregon. Oregon Dept Geol Min Ind Bull, 62: 3-34.

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 4 confirmed Holocene eruptive periods.

0475 ± 215 years Confirmed Eruption VEI: 2 (?)

Episode 1 | Eruption

Belknap Crater

0475 ± 215 years - Unknown

Evidence from Isotopic: 14C (calibrated)

The last period of known activity from Belknap Crater, which produced lava flows to the SW and NW from vents at the north and south bases of Belknap Crater, and ash eruptions from the northern summit crater, was ¹⁴C dated to about 1,495 BP (Taylor 1968, 1981; Wood and Kienle, 1990). Sherrod et al. (2004) reported two radiocarbon dates of 1,590 ± 160 and 1,400 ± 100 BP from the same sample; these have a corrected age range of 1,260-1,690 BP (475 ± 215 CE).

List of 4 Events for Episode 1 at Belknap Crater

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Explosion
- - - -	- - - -	Lava flow
- - - -	- - - -	Ash
0475 ± 215 years	- - - -	VEI (Explosivity Index)	VEI 2 (?)

0685 BCE ± 50 years Confirmed Eruption VEI: 2 (?)

Episode 1 | Eruption

South Belknap and Twin Craters

0685 BCE ± 50 years - Unknown

Evidence from Isotopic: 14C (calibrated)

The Twin Craters cinder cone at the SW margin of the Belknap lava field was active 2,600 years ago (Taylor, 1979), and produced lava flows that traveled south to Hand Lake. The radiocarbon date of 2,620 ± 150 BP on tree molds has a corrected age intercept of 2,750 BP with a range of 2,483-2,856 (Sherrod et al., 2004). A date of 2,635 ± 50 BP (685 ± 50 BCE) was obtained from roots in a tree mold from a South Belknap cone lava flow (Sherrod et al., 2004); this age is preferred by Sherrod et al. (2004) over a younger radiocarbon date of 1,775 ± 400 BP from a South Belknap lava flow because of a higher surface exposure age (cosmogenic helium). A maximum date of 2,800 ± 150 was obtained from beneath scoria from the Twin Crater eruption.

List of 5 Events for Episode 1 at South Belknap and Twin Craters

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Explosion
- - - -	- - - -	Lava flow
- - - -	- - - -	Cinder Cone
- - - -	- - - -	Scoria
0685 BCE ± 50 years	- - - -	VEI (Explosivity Index)	VEI 2 (?)

1071 BCE ± 241 years Confirmed Eruption VEI: 0

Episode 1 | Eruption

Little Belknap

1071 BCE ± 241 years - Unknown

Evidence from Isotopic: 14C (calibrated)

The Little Belknap shield volcano on the E flank of Belknap was ¹⁴C dated to about 2,883 BP (Taylor, in Wood and Kienle, 1990). This has a corrected age intercept of 2,975 BP, with a range of 2,780-3,262 BP (Sherrod et al., 2004), or 1071 ± 241 BCE.

List of 2 Events for Episode 1 at Little Belknap

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Lava flow
	1071 BCE ± 241 years	- - - -	VEI (Explosivity Index)	VEI 0

5050 BCE (?) Confirmed Eruption

Episode 1 | Eruption

Tamolitch lava flow

5050 BCE (?) - Unknown

Evidence from Correlation: Magnetism

The Tamolitch lava flows underlies young Belknap lavas and is considered from paleomagnetic evidence to have been erupted about 7,000 years ago (Deligne et al., 2017). These flows entered the McKenzie River south of present-day Carmen reservoir.

List of 1 Events for Episode 1 at Tamolitch lava flow

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Lava flow

Deformation History

There is no Deformation History data available for Belknap.

Emission History

There is no Emissions History data available for Belknap.

Photo Gallery

The broad Belknap shield volcano to the left seen here from Sand Mountain volcano to its NW, with the Three Sisters volcanoes in the background, is one of the youngest volcanoes in the central Oregon Cascades. The latest dated lava flow traveled 15 km W to the McKenzie River from a vent on the NE side of Belknap about 1,500 years ago.

Photo by Lee Siebert, 1981 (Smithsonian Institution).

Little Belknap shield volcano, seen here from the side of Belknap on the west with Black Crater in the background, formed about 2,900 years ago. Lava flows from Little Belknap, buttressed against the higher Belknap volcano on the west, spread primarily to the east.

Photo by Lee Siebert, 1982 (Smithsonian Institution).

The McKenzie Pass area in the central Oregon Cascades contains one of the largest concentrations of recent volcanism in the United States. Belknap shield volcano, seen here from Black Crater to the SE, is capped by a smaller snow-covered cone. Lava flows from Belknap and the smaller Little Belknap shield volcano in front of it cover nearly 100 km². Most of the largely unvegetated flows were erupted between about 2,900 and 1,500 years ago.

Photo by Lee Siebert, 1995 (Smithsonian Institution).

Little Belknap (upper left) is an example of a small shield volcano in a continental margin setting. Little Belknap was constructed on the E flank of Belknap volcano and erupted lava flows over the McKenzie Pass area of the central Oregon Cascades about 2,900 years ago. Collapsed lava tubes that fed the flows diverge radially away from the summit. The summit of Mount Washington appears above the horizon to the right.

Photo by Lee Siebert, 1995 (Smithsonian Institution).

Lava flows from Little Belknap shield volcano in the central Cascade Range of Oregon on the right skyline diverge around a kipuka, a forested island of pre-eruption terrain in the center of the photo. Kipuka is a Hawaiian term for older land surrounded by lava flows.

Photo by Lee Siebert, 1995 (Smithsonian Institution).

The lava flow in the foreground, with snow-capped Mount Jefferson in the background, was emplaced about 2,600-2,900 years ago from Yapoah scoria cone on the north flank of North Sister. Lava flows in the middle of the photo originated from the Little Belknap shield volcano, part of one of the largest concentrations of recent volcanism in the continental United States: the McKenzie Pass area of the central Oregon Cascade Range.

Photo by Lee Siebert, 1995 (Smithsonian Institution).

Lava flows in the foreground originated about 1,500 years ago from the South Belknap scoria cone below the skyline near the center of this photo. South Belknap scoria cone lies below Belknap Crater, a cone on the Belknap shield volcano. The lower peak on the right skyline is Little Belknap, a shield volcano constructed on the E flank of Belknap. Largely unvegetated lava flows cover nearly 100 km² in the McKenzie Pass area.

Photo by Lee Siebert, 1995 (Smithsonian Institution).

The South Belknap scoria cone on the left skyline was constructed on the SW flank of Belknap shield volcano (upper right) about 2,600 years ago during an eruption that produced lava flows towards the south. The foreground lava flows originated from Belknap.

Photo by Lee Siebert, 1995 (Smithsonian Institution).

GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

The following 1 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections, and may be availble for research (contact the Rock and Ore Collections Manager). Catalog number links will open a window with more information.

Catalog Number	Sample Description	Lava Source	Collection Date
NMNH 112584-28	Basalt	--	--

External Sites

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 Belknap. 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 Belknap. 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 Belknap

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).