Plate Tectonics

Introduction to Volcanology

In this course, Dr Tom Pering (University of Sheffield) provides an introduction to the field of volcanology. In the first module, we think about plate tectonics, outlining the areas in which volcanic activity takes place, key types of volcanoes, and the relationship between magma viscosity and eruption style. The second module looks at how volcanic events are classified, focused on the Volcanic Explosivity Index (VEI), and the third examines some of the major hazards associated with eruptions. In the fourth module, we consider the key things volcanologists monitor to determine the likelihood of an eruption, such as increases in gases released by a volcano. We conclude with a fifth module discussing case studies which illustrate some important aspects of volcanology.

Plate Tectonics

In this module, we think about how plate tectonics determine the distribution and characteristics of volcanic activity. We focus on: (i) the three main areas in which volcanism is generated – constructive and destructive plate boundaries, and volcanic hotspots; (ii) two key types of volcano – stratovolcanoes and shield volcanoes – and the role of magma viscosity in shaping style of volcanism; (iii) the factors which control magma viscosity, notably silica content; (iv) why high viscosity magma is associated with destructive boundaries, and low viscosity magma with hotspots; (v) the three components of magma - melt, crystals, and gas.