Details of Award
NERC Reference : NE/C509958/1
Dynamics of magma chambers and conduit flows during volcanic eruptions using the Soufriere Hills Volcano, Montserrat as a natural laboratory.
Grant Award
- Principal Investigator:
- Prof. RS Sparks, University of Bristol, Earth Sciences
- Grant held at:
- University of Bristol, Earth Sciences
- Science Area:
- Earth
- Overall Classification:
- Earth
- ENRIs:
- Environmental Risks and Hazards
- Science Topics:
- Volcanic Processes
- Geohazards
- Abstract:
- Volcanoes in some ways are simple. At around 100 kilometres depth in the Earth rocks are so hot that quite small changes in conditions can make them melt. The melt (known as magma) is lighter than the rock so rises to the Earth's surface along channels and cracks; the same force (known as buoyancy when one material is lighter than another) cause balloons to rise in air. The ascent of magma is not, however, straightforward because, it is typically very viscous and so flows slowly. The magma has to break rocks and push them out the way and this requires large pressures; this is why volcanic eruptions are associated with lots of small earthquakes. Also magmas can solidify as they ascend by cooling against the surrounding cold rocks or by losing volcanic gases dissolved in the magma at high pressures deep in the Earth. Sometimes magma gathers in large chambers under volcanoes where it is stored between eruptions. Understanding how a volcano works is therefore largely a matter of knowing how fast magma will flow from the magma chamber through narrow conduits to the surface: if it moves too slowly then it never erupts, if it moves quite slowly the volcanic gas escapes and a lava erupts, and if it flows too fast the gases build up enormous pressures and the magma explodes. The research aims to understand these flows which turn out to be complicated. There are a large number of parameters that influence the flows, such as the magma temperature, the amount of gas, the size of the magma chamber, the width of the conduit and many more. What makes these flows complex and quite difficult to understand is that very small changes of some property (such as the temperature of the magma) can result in enormous changes in behaviour. Volcanoes thus are a bit like the climate where many factors, such as variations in distance from the sun, the exchange of heat between the oceans and atmosphere, cloud cover and the spin of the Earth, affect how the atmosphere behaves and the weather we get. The approach to getting better forecasts of volcanic eruptions or the weather is to develop mathematical models of these complex systems and compare the results with observations. With modern computers it is possible to take account of many of the flow processes in volcanoes in mathematical models. Despite a lot of research models of volcanoes are still quite simple and do not yet take account of all the complexities of nature. There is a great deal to do and the central aim of the project is to produce much better and more realistic models. Part of the problem is that some of the properties of magmas and volcanic systems are not known very well; for example the size of a magma chamber is very difficult to measure. In addition properties of magma that govern how fast it flows are not well-known and are very hard to measure in the laboratory. Models are of no real interest unless they can help explain observations of how volcanoes behave and can be compared with observations to see if they are any good. Thus this project is going to use observations from the Soufriere Hills Volcano in Montserrat which has been erupting almost continuously since 1995. It is arguably the best scientifically documented volcano in the world and has large amounts of data on earthquakes, the deformation of the ground, the emissions of volcanic gas and magma, and the properties of the magma. In February 2003 UK and US scientists installed an instrument called a strainmeter in four deep boreholes. This instrument measures how rocks are squeezed as magma flows. By great luck on 12th July 2003 a huge mass of lava fell off the volcano into the sea and the expansion of the magma chamber caused by removal of the weight of lava was recorded on the strainmeters. This volcano will be our laboratory: nature is carrying out a wonderful experiment and we can test our models, use them to interpret the behaviour of the volcano and eventually help to make forecasts.
- NERC Reference:
- NE/C509958/1
- Grant Stage:
- Completed
- Scheme:
- Standard Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Standard Grant
This grant award has a total value of £186,714
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £118,253 | £7,347 | £6,718 | £54,396 |
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