Oct 21st 2014

Volcanic Eruptions: a material science (Coursera)

Volcanic eruptions are a powerful demonstration of the energy of the Earth´s interior. A materials-based understanding of the evolution of erupting systems provides a quantitative physico-chemical description of the nature of lava and magma and the role of experiments in quantifying the eruptive process.

Geoscientists define a “living planet” as one with active volcanism. By this definition our Earth is very much alive, with many eruptions each year and with a far greater number of “active volcanoes” that can potentially erupt in any given year.

In detail, each eruption is different. Every volcano is its own physical and chemical system, occurs in its own geological location, is subjected to its local stress field, and is at its own stage in evolution in geological time. External triggers of volcanic eruptions are also believed to play an important role.

Yet powerful generalisations and models of volcanic eruptions are indeed possible and in fact very useful in dealing with the consequences of volcanic eruptions.

How are such models constructed? They must rest on a basis of a mechanistic understanding of what volcanoes are, and what they are doing – not just during eruptions but also in the events leading up to eruptions, and not just at the Earth´s surface but also at depth, where the magma is being prepared for the next eruption.

In addition to field observations of past eruptions, monitoring of signals from magmatic systems, and computer-based simulation of volcanic eruptions, increasingly, high pressure and high temperature experiments are employed in order to answer the question of how volcanic systems work.

These controlled laboratory conditions for experimental volcanology are transforming the study of volcanoes from a chiefly observational discipline where eruptive mechanisms were developed via theoretical analysis of such observations, into a fully modern scientific discipline where such theoretical approaches are either verified or rejected, by the experimental picture of what is possible and what is not.

This course shows you how such experimental insight is obtained and what it tells us about erupting volcanoes.