Éruptions simultanées de basalte alcalin et de hawaiite au mont Cameroun (28 mars–17 avril 1999)

Dennielou, Bernard; Bardintzeff, Jacques-Marie; Cheminée, J. L.; Ngounouno, Ismaı̈la; Lissom, Justin; Nkoumbou, Charles; Étamé, Jacques; Hell, J.V.; Tanyileke, Gregory; N’ni, Jean; Ateba, Bekoa; Ntepe, Ntomu; Nono, Alexandre; Wandji, Pierre; Fosso, Jacob; Nkouathio, D. G.

doi:10.1016/s1251-8050(00)01454-3

Cited by 25 publications

(58 citation statements)

References 4 publications

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“…Analytical precision and accuracy are comparable to the values reported by Fitton et al (1998). The whole-rock compositions of the studied samples are presented in Table 6 alongside a reanalysis of the 1922, 1959 and 1982 samples of Fitton et al (1983); the 1999 samples of Deruelle et al (2000) and the 1999/2000 samples of Suh et al (2003). The results of the reanalyzed samples remained the same within the precision limits.…”

Section: Whole Rock Geochemistrysupporting

confidence: 77%

“…Whole-rock XRF major and trace element compositions including CIPW norms of the 1959 Mt. Cameroon lavas together with data ranges for lavas from 1922 and 1982 (Fitton et al 1983);(Deruelle et al 2000) some of which were re-analysed at the same time with our samples. The 1954 data are from Suh et al (2007).…”

Section: Whole Rock Geochemistrymentioning

confidence: 99%

“…This study concerns the 1959 lava flow field. The 1982 and 2000 eruptions have (Fitton et al 1983;Deruelle et al 2000;.…”

Section: Introductionmentioning

confidence: 99%

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The Mount Cameroon 1959 compound lava flow field: morphology, petrography and geochemistry

et al. 2008

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The Mount Cameroon 1959 compound lava flow field (volume ~3.4 × 10 7 m 3 ; mean effusion rate ~13 m 3 s -1 -18 m 3 s -1 ) is the only twentieth century eruption not following the NE-SW fracture system, the pathway for other recorded eruptions. The eruption occurred at two sites: 2006 m-1961 m and 1500 m, typically an aa flow with small pahoehoe channels in proximal regions. Morphologically, lava tubes and inflation hollows characterize upper flow regions while compression ridges and lava pinnacles characterize distal regions. Evidence of lava flow stagnation with time is provided by distinct layers at channel walls in proximal zones. Such channels are very narrow, deep, with poorly developed levee structures, attesting to high effusion rate and initial rapid advance of lava. The 1959 basanites show geochemical signatures and textural features indicating early fractionation of olivine and diopside, followed by Fe-Ti oxides and plagioclase. More evolved 1961 m vents lavas show higher incompatible and lower compatible element contents than those from the 1500 m sites. We interpret this to mean that residual more evolved magma of the 1954 eruption was initially forced out by degassing of a new less evolved magma batch, which finally drained out at the lower 1500 m site, the two magma batches not mixing. Incompatible elements indicate that the 1959 lava is similar to other historic lavas. However, subtle differences in compatible and incompatible element ratios (e.g. V/Rb) suggest that magma is erupted from the volcano in discrete batches from different magma storage regions rather than from a single large evolving chamber. The low whole-rock Mg contents (5.5 wt% MgO, average Mg# = 33.9) and high differentiation index values (36.7-38.5) for the 1959 lavas show that they are the most fractionated of all twentieth century Mt. Cameroon lavas.The Mount Cameroon 1959 compound lava flow field: morphology, petrography and geochemistry

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Section: Whole Rock Geochemistrysupporting

confidence: 77%

Section: Whole Rock Geochemistrymentioning

confidence: 99%

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The Mount Cameroon 1959 compound lava flow field: morphology, petrography and geochemistry

et al. 2008

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“…Mount Cameroon has given rise to several catastrophic events over the past few years: eruptions in 1999 and 2000 that led to villages being evacuated (Déruelle et al 2000;Suh et al 2003), many earthquakes (Ambeh and Fairhead 1991;Ateba and Ntepe 1997;Ubangoh et al 1997) including the destructive 1999 earthquake at Buea, landslides and mudflows that killed 24 people at Limbe in 2001 (Ayonghe et al 2004) and four people at Buea in 2006. These types of phenomena threaten, to various degrees, around 450,000 people and some of Cameroon's main infrastructure, including the Sonara oil refinery, the Limbe power station, and industrial and semi-industrial plantations (banana, hevea-rubber, tea or palm oil, cacao).…”

Section: Mount Cameroonmentioning

confidence: 99%

Multi-hazard risk mapping and assessment on an active volcano: the GRINP project at Mount Cameroon

et al. 2007

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International audienceTo help improve the safety of its population faced with natural disasters, the Cameroon Government, with the support of the French Government, initiated a programme of geological risk analysis and mapping on Mount Cameroon. This active volcano is subject to a variety of hazards: volcanic eruptions, slope instability and earthquakes. Approximately 450,000 people live or work around this volcano, in an area which includes one of Cameroon's main economic resources. An original methodology was used for obtaining the information to reply to questions raised by the authorities. It involves several stages: identifying the different geological hazard components, defining each phenomenon's threat matrix by crossing intensity and frequency indices, mapping the hazards, listing and mapping the exposed elements, analysing their respective values in economic, functional and strategic terms, establishing typologies for the different element-at-risk groups and assessing their vulnerability to the various physical pressures produced by the hazard phenomena, and establishing risk maps for each of the major element-at-risk groups (population, infrastructures, vegetation, atmosphere). At the end of the study we were able (a) to identify the main critical points within the area, and (b) provide quantified orders of magnitude concerning the dimensions of the risk by producing a plausible eruption scenario. The results allowed us to put forward a number of recommendations to the Cameroon Government concerning risk prevention and management. The adopted approach corresponds to a first level of response to the authorities. Later developments should make it possible to refine the quality of the methodology

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“…2). In 1999, two lava flows formed on the southern flank, the first producing a 3-kmlong lava field from a vent located about 2,650 ma.s.l., the second giving rise to a 14-km-long lava field from a vent (Déruelle et al 2000;Suh et al 2003). The last eruption occurred in 2000, when the lava poured out from a fissure in the summit area above 4,000 ma.s.l.…”

Section: Introductionmentioning

confidence: 99%

Lava flow hazard and risk at Mt. Cameroon volcano

et al. 2011

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Mt. Cameroon is one of the most active effusive volcanoes in Africa. About 500,000 people living or working around its fertile flanks are subject to significant threat from lava flow inundation. Lava flow hazard and risk were assessed by simulating probable lava flow paths using the DOWNFLOW code. The vent opening probability density function and lava flow length distribution were determined on the basis of available data from past eruptions at Mt. Cameroon volcano. Code calibration was performed through comparison with real lava flow paths. The topographic basis for simulations was the 90-m resolution SRTM DEM. Simulated lava flows from about 80,000 possible vents were used to produce a detailed lava flow hazard map. The lava flow risk in the area was mapped by combining the hazard map with digitized infrastructures (i.e., human settlements and roads). Results show that the risk of lava flow inundation is greatest in the most inhabited coastal areas comprising the town of Limbe, which constitutes the center of Cameroon's oil industry and an important commercial port. Buea, the second most important town in the area, has a much lower risk although it is significantly closer to the summit of the volcano. Nonnegligible risk characterizes many villages and most roads in the area surrounding the volcano. In addition to the conventional risk mapping described above, we also present (1) two reversed risk maps (one for buildings and one for roads), where each point on the volcano is classified according to the total damage expected as a consequence of vent opening at that point; (2) maps of the lava catchments for the two main towns of Limbe and Buea, illustrating the expected damage upon venting at any point in the catchment basin. The hazard and risk maps provided here represent valuable tools for both medium/long-term land-use planning and real-time volcanic risk management and decision making.

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Éruptions simultanées de basalte alcalin et de hawaiite au mont Cameroun (28 mars–17 avril 1999)

Cited by 25 publications

References 4 publications

The Mount Cameroon 1959 compound lava flow field: morphology, petrography and geochemistry

The Mount Cameroon 1959 compound lava flow field: morphology, petrography and geochemistry

Multi-hazard risk mapping and assessment on an active volcano: the GRINP project at Mount Cameroon

Lava flow hazard and risk at Mt. Cameroon volcano

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