What is the significance of large volcanic eruptions and how should they be defined?
Introduction: Explain why this is an important question and why the answer is not clear-cut and how you are going to approach the answer. You could break the answer down into effusive and explosive eruptions, but make sure you explain (and understand) how they differ. Things to consider in their significance: • Effects on local, regional and global scales. • Does significance depend on the location of the volcano, e.g. latitude, distance to human habitation etc. • Compare to frequency of smaller events, which has more profound consequences? • Global climate effects. • Tsunami. • Tephra. • What could the knock-on effects of these phenomena be? Impacts on people, land, global economy, air travel. • Look at examples. • What is the evidence for prehistoric large eruptions? • Relationship to other catastrophic natural phenomena e.g. impactors, earthquakes. Things to consider in defining them: • What are the different existing index (VEI, VSI, DVI, destructiveness index etc) rankings based o
