Locating the depth of magma supply for volcanic eruptions, insights from Mt. Cameroon
نویسندگان
چکیده
Mt. Cameroon is one of the most active volcanoes in Africa and poses a possible threat to about half a million people in the area, yet knowledge of the volcano's underlying magma supply system is sparse. To characterize Mt. Cameroon's magma plumbing system, we employed mineral-melt equilibrium thermobarometry on the products of the volcano's two most recent eruptions of 1999 and 2000. Our results suggest pre-eruptive magma storage between 20 and 39 km beneath Mt. Cameroon, which corresponds to the Moho level and below. Additionally, the 1999 eruption products reveal several shallow magma pockets between 3 and 12 km depth, which are not detected in the 2000 lavas. This implies that small-volume magma batches actively migrate through the plumbing system during repose intervals. Evolving and migrating magma parcels potentially cause temporary unrest and short-lived explosive outbursts, and may be remobilized during major eruptions that are fed from sub-Moho magma reservoirs.
منابع مشابه
New geochemical insights into volcanic degassing.
Magma degassing plays a fundamental role in controlling the style of volcanic eruptions. Whether a volcanic eruption is explosive, or effusive, is of crucial importance to approximately 500 million people living in the shadow of hazardous volcanoes worldwide. Studies of how gases exsolve and separate from magma prior to and during eruptions have been given new impetus by the emergence of more a...
متن کاملDegassing during quiescence as a trigger of magma ascent and volcanic eruptions
Understanding the mechanisms that control the start-up of volcanic unrest is crucial to improve the forecasting of eruptions at active volcanoes. Among the most active volcanoes in the world are the so-called persistently degassing ones (e.g., Etna, Italy; Merapi, Indonesia), which emit massive amounts of gas during quiescence (several kilotonnes per day) and erupt every few months or years. Th...
متن کاملForecasting volcanic eruptions
Forecasting is a central goal of volcanology. Intensive monitoring of recent eruptions has generated integrated timeseries of data, which have resulted in several successful examples of warnings being issued on impending eruptions. Ability to forecast is being advanced by new technology, such as broad-band seismology, satellite observations of ground deformation and improved field spectrometers...
متن کاملThe Magma Reservoirs
The rocky innards of the Earth locally melt to produce magma, which sometimes erupts as cataclysmic explosions. The energy released by these eruptions is matched only by that of large meteorite impacts. Whether large pools of magma generate huge volcanic eruptions, whose volume and duration can have global consequences for humanity, or solidify slowly within the Earth’s crust to form plutons (b...
متن کاملThermomechanical controls on magma supply and volcanic deformation: application to Aira caldera, Japan
Ground deformation often precedes volcanic eruptions, and results from complex interactions between source processes and the thermomechanical behaviour of surrounding rocks. Previous models aiming to constrain source processes were unable to include realistic mechanical and thermal rock properties, and the role of thermomechanical heterogeneity in magma accumulation was unclear. Here we show ho...
متن کامل