Available Weekly Reports
|Oku Volcanic Field|
There are no activity reports for Oku Volcanic Field.
Summary of eruption dates and Volcanic Explosivity Indices (VEI).
|Start Date||Stop Date||Eruption Certainty||VEI||Evidence||Activity Area or Unit|
|[ 1986 Aug 21 ]||[ 1986 Dec 30 (?) ]||Uncertain||Lake Nyos|
|[ 1550 ± 100 years ]||[ Unknown ]||Uncertain||3||Lake Nyos|
Numerous maars and basaltic cinder cones lie on or near the deeply dissected rhyolitic and trachytic Mount Oku massif along the Cameroon volcanic line. The Mount Oku stratovolcano is cut by a large caldera. The Oku volcanic field is noted for two crater lakes, Lake Nyos to the north and Lake Monoun to the south, that recently produced catastrophic carbon-dioxide gas release events. The August 15, 1984, gas release at Lake Monoun was attributed to overturn of stratified lake water, triggered by an earthquake and landslide. The Lake Nyos event on August 21, 1986, caused at least 1700 fatalities. The emission of around 1 cu km of magmatic carbon dioxide has been attributed either to overturn of stratified lake waters as a result of a non-volcanic process, or to phreatic explosions or injection of hot gas into the lake.