Global Volcanism Program

The Global Volcanism Program has no activity reports available for Tombel Graben.

The Global Volcanism Program has no Weekly Reports available for Tombel Graben.

The Global Volcanism Program has no Bulletin Reports available for Tombel Graben.

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude

224011

Unknown - Evidence Credible

500 m / 1,640 ft

4.758°N
9.717°E

Morphology

Volcano Landform
Cluster

Volcano Types
Volcanic field
Pyroclastic cone(s)
Maar(s)

Rock Types

Major
Trachybasalt / Tephrite Basanite
Basalt / Picro-Basalt

Tectonic Setting

Intraplate
Continental crust (> 25 km)

Population

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

234,623
234,623
434,892
4,087,423

Geological Summary

Young cinder cones and maars are abundant in the low-lying Tombel Graben (also referred to as the Tombel Plain) between Mount Cameroon and Mount Manengouba (within 4°58'N, 9°51'E and 4°33'N, 9°35'E). Mount Koupe, composed of Tertiary syenite, dominates the area. Activity began with the emission of large lava flows over Precambrian metamorphic rocks and Cretaceous sandstones, and concluded with explosive activity forming numerous cinder cones. The 800 km² volcanic field, which erupted basanitic, basaltic, and trachybasaltic rocks, contains three large lake-filled maars, including Barombi Mbo, a compound maar near the town of Kumba. Legends record an eruption of Le Djungo (also known as Mont Pelé) that destroyed a village; though a small craterless cone is marked along a fault line on a map in Nkono (2009, after Nkouathio et al., 2002) it's unclear what cone is being described by the story, because no noticeably younger or unvegetated cones are apparent in satellite imagery. Two samples taken from the Njombe area in the farthest SW part of the field were K-Ar dated as possible Holocene (Nkouathio et al., 2008), though the error was too large to be definitive.

References

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

Fitton J G, 1987. The Cameroon line, West Africa: a comparison between oceanic and continental alkaline volcanism. In: Fitton J G and Upton B G J (eds) Alkaline Igneous Rocks, Geol Soc Amer Spec Pub 30: 273-291.

Fitton J G, Dunlop H M, 1985. The Cameroon line, West Africa, and its bearing on the origin of oceanic and continental alkali basalt. Earth Planet Sci Lett, 72: 23-38.

Geze B, 1953. Les volcans du Cameroun occidental. Bulletin of Volcanology, 13: 63-92.

Nkouathio D G, Menard J-J, Wandji P, Bardintzeff J-M, 2002. The Tombel graben (West Cameroon): a recent monogenetic volcanic field of the Cameroon Line. J African Earth Sci, 35: 285-300.

Sato H, Aramaki S, Kusakabe M, Hirabayashi J-I, Sano Y, Nojiri Y, Tchoua F, 1990. Geochemical difference of basalts between polygenetic and monogenetic volcanoes in the central part of the Cameroon volcanic line. Geochem J, 24: 357-370.

Tchoua F M, 1971. Le volcanisme Strombolien de la plaine de Tombel (Cameroun). Annales Fac Sci, Yaounde, Cameroun, 7-8: 53-78.

Eruptive History

The Global Volcanism Program is not aware of any Holocene eruptions from Tombel Graben. If this volcano has had large eruptions (VEI >= 4) prior to 12,000 years ago, information might be found on the Tombel Graben page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

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

Tombel Plain

Cones

Feature Name

Feature Type

Elevation

Latitude

Longitude

Djungo, Le
Pele, Mont

Cone

474 m

4° 40' 54.00" N

9° 38' 35.00" E

Malinkam

Cone

444 m

4° 36' 32.00" N

9° 38' 46.00" E

Mbanga

Cone

277 m

4° 31' 47.00" N

9° 33' 17.00" E

Other

Feature Name

Feature Type

Elevation

Latitude

Longitude

Koupe

Intrusion

2038 m

4° 48' 4.00" N

9° 42' 25.00" E

Photo Gallery

Three lake-filled maars dot the Tombel Graben between Mount Cameroon (lower left) and lava flows from Manengouba volcano (top). The Mungo River runs from N to S across the right side of this Landsat image. The largest maar, Barombi Mbo, lies just west of the brown-colored area of the town of Kumba, and Barombi Koto is at the lower left. A large number of scoria cones, including the young cone of Le Djungo (Mont Pelé) dot the 10-20 km wide graben.

NASA Landsat image, 1999 (courtesy of Hawaii Synergy Project, Univ. of Hawaii Institute of Geophysics & Planetology).

The Tombel Graben is a series of grabens that contain a monogenetic volcanic field consisting largely of scoria cones, maars, and lava flows, several of which are seen in this 13 November 2019 Sentinel-2 satellite image (N at the top). The town of Malinkam is seen here, and the larger Malinkam cone about 2 km SW is approximately 1 km wide.

Satellite image courtesy of Copernicus Sentinel Data, 2019.

Smithsonian Sample Collections Database

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

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 Tombel Graben. 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 Tombel Graben. 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 Tombel Graben

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).