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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 0.914°S
  • 36.446°E

  • 2776 m
    9105 ft

  • 222100
  • Latitude
  • Longitude

  • Summit

  • Volcano

The Global Volcanism Program has no activity reports for Longonot.

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

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

Basic Data

Volcano Number

Last Known Eruption



1863 CE

2776 m / 9105 ft


Volcano Types

Pyroclastic cone(s)

Rock Types

Trachyte / Trachyandesite
Trachybasalt / Tephrite Basanite

Tectonic Setting

Rift zone
Continental crust (> 25 km)


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

Geological Summary

The trachytic Longonot stratovolcano SE of Lake Naivasha in the Gregory Rift valley contains a 8 x 12 km caldera. Formation of the caldera accompanied large explosive eruptions about 21,000 years ago. A large central cone that was constructed within the caldera forms the 2776-m-high summit of the volcano. The younger cone is truncated by a circular, 1.8-km-wide crater. Post-caldera lavas are found on the caldera floor and the volcano's flanks, marking a late stage of effusive eruptions. A well-preserved satellitic cone is located on the NE flank. Masai tradition records a lava flow on the northern flank during the 19th century. Similarly youthful-looking lava flows occur on the SW flank.


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

Richard J J, Neumann van Padang M, 1957. Africa and the Red Sea. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI 4: 1-118.

Rogers N W, Evans P J, Blake S, Scott S C, Hawkesworth C J, 2004. Rates and timescales of fractional crystallization from 238U-230Th-226Ra disequilibria in trachyte lavas from Longonot volcano, Kenya. J Petr, 45: 1747-1776.

Scott S C, 1980. The geology of Longonot volcano, Central Kenya: a question of volumes. Phil Trans Roy Soc London, Ser A, 296: 438-466.

Thompson A O, Dodson R G, 1963. Geology of the Naivasha area. Geol Surv Kenya Rpt, 55: 1-80.

Williams L A J, Macdonald R, Chapman G R, 1984. Late Quaternary caldera volcanoes of the Kenya Rift Valley. J Geophys Res, 89: 8553-8570.

Eruptive History

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1863 ± 5 years Unknown Confirmed 0 Anthropology Northern flank
1330 BCE ± 100 years Unknown Confirmed   Radiocarbon (uncorrected)
7200 BCE ± 100 years Unknown Confirmed   Radiocarbon (uncorrected)

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.


Ol Olongot | Olonongot

Photo Gallery

The broad trachytic Longonot stratovolcano SE of Lake Naivasha is seen from the flanks of Suswa volcano (SSW of Longonot) rising above the floor of the Eastern Rift Valley of Kenya. The modern cone was constructed within a broad 8 x 12 km caldera and itself contains a smaller 1.8-km-wide summit crater that gives the summit a flat profile. Post-caldera lavas are found on the caldera floor and the volcano's flanks. Masai tradition records a lava flow on the northern flank during the 19th century.

Photo by Tom Jorstad, 1990 (Smithsonian Institution).

Smithsonian Sample Collections Database

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

Affiliated Sites

Large Eruptions of Longonot 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).
WOVOdat 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.
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).
MODVOLC - HIGP MODIS Thermal Alert System 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.
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.