Exploring the roots of volcanic eruptions: Insights from deep magmatic processes

Feb 25, 2013
Exploring the roots of volcanic eruptions: Insights from deep magmatic processes
A small eruption of the Soufriere Hills Volcano, Montserrat. Credit: Professor Steve Sparks

An exploration of deep magmatic processes occurring in the Earth's crust beneath volcanoes, which could contribute to linking these physical processes at depth with volcanic eruptions at the surface, has been carried out by researchers from the University of Bristol and the Swiss Federal Institute in Zurich. The experimental study is published in Chemical Geology.

Volcanic eruptions represent a substantial threat for almost 500 million people living close to violently erupting volcanoes.  To distinguish whether an eruption will be explosive or not, it is fundamental to explore what occurs several kilometres below the ground.

Since there is no possibility of accessing the Earth's interior directly, experiments simulating magmatic processes at depth are of vital interest.  Rheology – the study of flowing material undergoing deformation – is used to constrain the physics and dynamics of magmas.  The main parameter to determine in rheological investigations is , which is the internal resistance of a material to flow.

Dr Mattia Pistone of Bristol's School of and colleagues show that the contemporaneous presence of crystals and bubbles induce a significant difference in the rheology of magmas with respect to two-phase (bubble or + melt) systems.

Crystallization and efficient gas removal from magmatic bodies lead to a substantial increase in magma viscosity and, eventually, to their 'viscous death' in the Earth's crust.  On the contrary, the significant decrease of viscosity associated with the presence of limited volumes of gas could promote mobilization of the magma bodies and the generation of large explosive eruptions.

Dr Pistone said: "A possible implication of these new experimental findings is that gas-bearing magmas are rheologically mobile and may have a high tendency to feed .

"For a truly multidisciplinary application to volcanic risk and mitigation, combining the experimental experience with the direct real-time monitoring of active volcanoes would greatly help volcanologists to decipher the precursor events – volcanic tremor, degassing, ground deformation – and extract from them the right information on the magmatic processes occurring at depth.  This might be the first small step for multidisciplinary volcanology, but a giant leap towards volcanic forecast."  

Explore further: Strong quake hits east Indonesia; no tsunami threat

More information: Pistone, M et al. Rheology of volatile-bearing crystal mushes: mobilization vs. viscous death, Chemical Geologywww.sciencedirect.com/science/… ii/S0009254113000570

add to favorites email to friend print save as pdf

Related Stories

Taking the 'pulse' of volcanoes using satellite images

Nov 05, 2012

A new study by scientists at the University of Miami (UM) Rosenstiel School of Marine & Atmospheric Science uses Interferometric Synthetic Aperture Radar (InSAR) data to investigate deformation prior to the eruption of active ...

Recommended for you

Strong quake hits east Indonesia; no tsunami threat

10 hours ago

A strong earthquake struck off the coast of eastern Indonesia on Sunday evening, but there were no immediate reports of injuries or damage, and authorities said there was no threat of a tsunami.

Scientists make strides in tsunami warning since 2004

Dec 19, 2014

The 2004 tsunami led to greater global cooperation and improved techniques for detecting waves that could reach faraway shores, even though scientists still cannot predict when an earthquake will strike.

Trade winds ventilate the tropical oceans

Dec 19, 2014

Long-term observations indicate that the oxygen minimum zones in the tropical oceans have expanded in recent decades. The reason is still unknown. Now scientists at the GEOMAR Helmholtz Centre for Ocean Research ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.