Ardoukôba

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  • Last Known Eruption
  • 11.58°N
  • 42.47°E

  • 298 m
    977 ft

  • 221126
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Most Recent Bulletin Report: December 1978 (SEAN 03:12)


New data on November eruption

The eruption of Ardoukoba began on 7 November. During the preceding 24 hours, about 800 earthquakes M < 3.3 had been recorded. These events occurred at the end of the Ghoubbat al Kharab (figure 2), just S of the rift and ~6 km SE of the eruption site.

Figure 2. Rock types, faults, and old volcanic cones in the Ardoukoba Rift, after Needham and others (1976). An overprint, from M. Krafft, shows the active vents and lava flows from the 7-14 November 1978 eruption and the zone of active faulting accompanying the eruption.

After a brief period of gas emission, lava fountaining began from a 500-m-long, newly opened fissure. Three spatter cones formed on this fissure, but the primary activity soon shifted about 1/2 km to the SE. For the first 2-4 hours as much as 0.5 x 106 m3 of lava was extruded per hour, but the extrusion rate declined rapidly and by the 5th or 6th day had decreased by an order of magnitude.

By 9 November, only the main vent was still active. A cone (named Gira-le-Koma) about 30 m high, 200 m long, and 25 m wide, with a 60° external slope, had formed around this vent, which contained a small lava lake. On 13 November the level of the lava lake dropped rapidly, then the lake disappeared. Scoria and bombs were ejected briefly before the eruption ended on 14 November.

The total volume of lava emitted was estimated to be at least 12 x 106 m3. Lava covered an area of slightly more than 3 km2. Flow thicknesses reached 25 m but usually ranged from 1 to 2 m. About 25 fissures, parallel to the NW-SE trend of the rift, opened during the activity. Most fissures were from 1-2 mm to about 1 m wide, but there was one short segment of 3 m width. Many of the fissures also showed a component of normal movement, with scarps up to 1/2 m high.

Reference. Needham and others, 1976, The accreting plate boundary: Ardoukoba Rift (northeast Africa) and the oceanic rift system: Earth and Planetary Science Letters, v. 28, p 439-453.

Further References. Abdallah, A., and others, 1979, Relevance of Afar seismicity and volcanism to the mechanics of accreting plate boundaries: Nature, v. 282, p. 17-23.

Demange, J., and Tazieff, H., 1978, The "tectonic" eruption of the Ardoukoba (Djibouti): C.R. Acad. Sci. Paris, Ser. D, v. 287, p. 1269-1272.

Hernandez, J., and Ruegg, J.C., eds., 1980, Colloque Rift d'Asal: Réunion extraordinaire de la Société Géologique de France: Bulletin de la Societé Géologique de France, serie 7, t. XXII, no. 6, p. 797-1013.

Tarantola, A., Ruegg, J.C., and Lepine, J.C., 1979, Geodetic evidence for rifting in Afar: A brittle-elastic model for the behavior of the lithosphere: Earth and Planetary Science Letters, v. 45, p. 435-444.

Information Contacts: M. Krafft, Cernay.

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

Index of Bulletin Reports


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

11/1978 (SEAN 03:11) Basaltic lava flows; first eruption in as much as 3,000 years

12/1978 (SEAN 03:12) New data on November eruption




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


11/1978 (SEAN 03:11) Basaltic lava flows; first eruption in as much as 3,000 years

The crew of a French observation aircraft saw an eruption early 8 November in a virtually uninhabited area SE of Lake Assal. On the preceding day a series of weak earthquakes was felt in the city of Djibouti and two larger shallow events were located by the U. S. Geological Survey's National Earthquake Information Center (USGS/NEIC). The first, mb 5.2, occurred on 7 November at 2006 (felt as a sharp shock in Djibouti) and the second, mb 5.0, on 8 November at 0808. Hypocenters calculated by the USGS for these events are 8 and 17 km WSW of the eruption, or well within the location error for events in this region.

Two basaltic lava flows were reportedly extruded: one flow traveled ~1 km to the SE, the other ~0.5 km to the NW. Lava effusion rates reached an estimated maximum of 1,000 m3/minute [but see 0.5 x 106 m3/hour below]. Ash clouds rose ~300 m and larger pyroclastics ~70 m. The eruption formed a crater ~30 m in diameter and built a cone ~100 m high.

Activity began to decline 14 November and within two days only steaming was visible. As of 22 November, some vapor emission continued from subsidiary vents. No casualties or damage were reported.

Although no previous eruptions have been reported in the area in historic time, the most recent lava flows are substantially younger than sediments 14C dated at 5300 B.P., and are thought to be younger than 3,000 B.P. Eruptions are also mentioned in local legends (Delibrias and others, 1975).

Reference. Delibrias, G., Marinelli, G., and Stieltjes, L., 1975, Spreading rate of the Asal Rift, in Pilger, A. and Rosler, A. (eds.), Afar Depression of Ethiopia: Inter-Union Commission on Geodynamics Scientific Report No. 14: E. Schweitzerbart'sche Verlagsbuchhandlung, Stuttgart.

Information Contacts: W. Clarke, U.S. Embassy, Djibouti; M. Krafft, Cernay, France; USGS/NEIC.

12/1978 (SEAN 03:12) New data on November eruption

The eruption of Ardoukoba began on 7 November. During the preceding 24 hours, about 800 earthquakes M < 3.3 had been recorded. These events occurred at the end of the Ghoubbat al Kharab (figure 2), just S of the rift and ~6 km SE of the eruption site.

Figure 2. Rock types, faults, and old volcanic cones in the Ardoukoba Rift, after Needham and others (1976). An overprint, from M. Krafft, shows the active vents and lava flows from the 7-14 November 1978 eruption and the zone of active faulting accompanying the eruption.

After a brief period of gas emission, lava fountaining began from a 500-m-long, newly opened fissure. Three spatter cones formed on this fissure, but the primary activity soon shifted about 1/2 km to the SE. For the first 2-4 hours as much as 0.5 x 106 m3 of lava was extruded per hour, but the extrusion rate declined rapidly and by the 5th or 6th day had decreased by an order of magnitude.

By 9 November, only the main vent was still active. A cone (named Gira-le-Koma) about 30 m high, 200 m long, and 25 m wide, with a 60° external slope, had formed around this vent, which contained a small lava lake. On 13 November the level of the lava lake dropped rapidly, then the lake disappeared. Scoria and bombs were ejected briefly before the eruption ended on 14 November.

The total volume of lava emitted was estimated to be at least 12 x 106 m3. Lava covered an area of slightly more than 3 km2. Flow thicknesses reached 25 m but usually ranged from 1 to 2 m. About 25 fissures, parallel to the NW-SE trend of the rift, opened during the activity. Most fissures were from 1-2 mm to about 1 m wide, but there was one short segment of 3 m width. Many of the fissures also showed a component of normal movement, with scarps up to 1/2 m high.

Reference. Needham and others, 1976, The accreting plate boundary: Ardoukoba Rift (northeast Africa) and the oceanic rift system: Earth and Planetary Science Letters, v. 28, p 439-453.

Further References. Abdallah, A., and others, 1979, Relevance of Afar seismicity and volcanism to the mechanics of accreting plate boundaries: Nature, v. 282, p. 17-23.

Demange, J., and Tazieff, H., 1978, The "tectonic" eruption of the Ardoukoba (Djibouti): C.R. Acad. Sci. Paris, Ser. D, v. 287, p. 1269-1272.

Hernandez, J., and Ruegg, J.C., eds., 1980, Colloque Rift d'Asal: Réunion extraordinaire de la Société Géologique de France: Bulletin de la Societé Géologique de France, serie 7, t. XXII, no. 6, p. 797-1013.

Tarantola, A., Ruegg, J.C., and Lepine, J.C., 1979, Geodetic evidence for rifting in Afar: A brittle-elastic model for the behavior of the lithosphere: Earth and Planetary Science Letters, v. 45, p. 435-444.

Information Contacts: M. Krafft, Cernay.

The Ardoukôba (Asal) Rift in Djibouti, trending NW from the Red Sea, contains a broad area of youthful fissure vents between Lake Asal and the Ghoubbat al Kharab gulf. The rift is subaerially exposed over a 12 km distance between these two bodies of water and contains numerous basaltic cinder and spatter cones. The silicic centers of Eger Alayta and Asa Aleyta, on the north and south sides of the rift, are remnants of a Pleistocene silicic center that has been disrupted and spread apart by the rift. Magma-water interaction has produced tuff cones, some of which form islands or are breached by the sea. The most recent lava flows are younger than lake sediments deposited 5300 years ago. These lavas were thought to have been erupted during the past 3000 years (Delibrias et al., 1975). The Ardoukôba fissure erupted in 1978, producing a small cinder cone and lava flows that covered part of the rift floor near the Red Sea.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1978 Nov 7 1978 Nov 14 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.


Cones

Feature Name Feature Type Elevation Latitude Longitude
Baddi Koma Tuff cone 11° 33' 0" N 42° 32' 0" E
Gira-le-Koma Cone
Kodda Ginni Koma Tuff cone 11° 32' 0" N 42° 32' 0" E
Ounda Ginna Koma Tuff cone 11° 33' 0" N 42° 32' 0" E
The Ardoukôba (Asal) Rift in the center of the photo lies in Djibouti and trends NW from the Red Sea. Ardoukoba contains a broad area of youthful fissure vents between Lake Asal (bounded by white saline deposits at the left) and the Ghoubbat al Kharab gulf (upper right). The most recent lava flows are younger than lake sediments deposited 5300 years ago. The Ardoukôba fissure erupted in 1978, producing a small cinder cone and lava flows that covered part of the rift floor near the Red Sea.

NASA Space Shuttle image ISS004-E-11422, 1992 (http://eol.jsc.nasa.gov/).

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.

CNR-CNRS, 1975. Geological Maps of Afar: 1, Northern Afar (1971); 2, Central and Southern Afar (1975). La Celle St Cloud, France: Geotechnip.

Delibrias G, Marinelli G, Stieltjes L, 1975. Spreading rate of the Asal Rift: A geological approach. In: Pilger A and Rosler A (eds) {Afar Depression of Ethiopia}, Inter-Union Comm Geodynam Sci Rpt, 14: 214-221, Stuttgart: E Schweizerbart'sche.

Lahitte P, Gillot P-Y, Courtillot V, 2003a. Silicic central volcanoes as precursors to rift propagation: the Afar case. Earth Planet Sci Lett, 207: 103-116.

Lahitte P, Gillot P-Y, Kidane T, Courtillot V, 2003b. New age constraints on the timing of volcanism in central Afar, in the presence of propagating rifts. J Geophys Res, 108: doi: 10.1029/2001JB001689.

Needham H D, Choukroune P, Cheminee J L, Le Pichon X, Francheteau J, Tapponnier P, 1976. The accreting plate boundary: Ardoukoba Rift (Northeast Africa) and the oceanic rift valley. Earth Planet Sci Lett, 28: 439-453.

Smithsonian Institution-SEAN, 1975-89. [Monthly event reports]. Bull Scientific Event Alert Network (SEAN), v 1-14.

Stieltjes L, 1974. Geologic map of the Asal Rift. Bur Recherches Geol Minieres France, 1:50,000.

Volcano Types

Fissure vent(s)
Pyroclastic cone(s)
Tuff cone(s)

Tectonic Setting

Rift zone
Intermediate crust (15-25 km)

Rock Types

Major
Basalt / Picro-Basalt
Trachybasalt / Tephrite Basanite
Rhyolite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
2,895
2,895
6,898
560,146

Affiliated Databases

Large Eruptions of Ardoukôba 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.