South Island

Photo of this volcano
Google Earth icon
  Google Earth Placemark
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 2.63°N
  • 36.6°E

  • 800 m
    2624 ft

  • 222020
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for South Island.

The Global Volcanism Program has no Weekly Reports available for South Island.

The Global Volcanism Program has no Bulletin Reports available for South Island.

The southernmost and largest of the three volcanic islands in Lake Turkana, South Island contains numerous tuff cones. Fresh-looking lava flows, erupted from a N-S fissure extending the 11-km length of the island, form much of the eastern shoreline. South Island (sometimes referred to as Hohnel Island) rises 320 m above the lake to a height of 800 m and is part of a volcanic horst that extends 10 km to the north beneath the lake surface. Early stage tuff cone formation may have been associated with a high stand of Lake Turkana dated at about 10,000 years ago, and later subaerial activity postdates the last high stand of the lake about 3200 years ago. The dominantly basaltic lava flows are morphologically similar to the youthful Holocene flows of The Barrier volcano at the south end of Lake Turkana. An eruption from a scoria cone on South Island was witnessed during Count von Teliki's 1888 expedition.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1888 Unknown Confirmed 1 Historical Observations

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
Hohnel Island | von Hohnel Island
South Island (left center) is the southernmost and largest of the three volcanic islands in Lake Turkana. North is to the left in this Space Shuttle view. Fresh-looking lava flows, erupted from a fissure extending the 11-km length of the island, form much of the eastern (top) shoreline. The basaltic lava flows are morphologically similar to youthful Holocene flows of The Barrier volcano, whose lower flanks can be seen at the far right. An eruption from a scoria cone on South Island was witnessed during Count von Teliki's 1888 expedition.

NASA Space Shuttle image ISS006-E-5095, 2002 (http://eol.jsc.nasa.gov/).
South Island (right) is the southernmost and largest of the three volcanic islands in Lake Turkana. The island (sometimes referred to as Hohnel Island) contains numerous tuff cones and rises 320 m above the lake surface. Fresh-looking lava flows, erupted from a N-S fissure extending the 11-km length of the island, form much of the eastern shoreline. An eruption from a scoria cone on South Island was witnessed during Count von Teliki's 1888 expedition.

Photo by Doron, 1999 (http://commons.wikimedia.org/wiki/Image:LakeTurkanaSouthIsland.jpg).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Bloomer S H, Curtis P C, Karson J A, 1989. Geochemical variation of Quaternary basaltic volcanoes in the Turkana Rift, northern Kenya. J African Earth Sci, 8: 511-532.

Dunkley P N, Smith M, Allen D A, Darling W G, 1993. The geothermal activity and geology of the northern sector of the Kenya Rift Valley. Brit Geol Surv Res Rpt, SC/93/1: 1-185.

Karson J A, Curtis P C, 1994. Axial Quaternary volcanic centers in the Turkana rift, N. Kenya. J African Earth Sci, 18: 15-35.

Ochieng J O, Wilkinson A F, Kagasi J, Kimomo S, 1988. Geology of the Loiyangalani area. Rpt Mines Geol Dept Kenya, 107: 1-53.

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.

Volcano Types

Stratovolcano
Tuff cone(s)

Tectonic Setting

Rift zone
Continental crust (> 25 km)

Rock Types

Major
Basalt / Picro-Basalt
Trachybasalt / Tephrite Basanite
Phono-tephrite / Tephri-phonolite
Trachyandesite / Basaltic trachy-andesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
0
0
1,959
98,303

Affiliated Databases

Large Eruptions of South Island 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).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.