Revision Exercises

1. What is a pyroclastic flow, and how can these flows be generated?
2. What is a lahar, and how are lahars generated?
3. Why are pyroclastic flows and lahars considered, historically, to be the greatest 'killers' of all volcanic events?
4. What can be done to mitigate these volcanic hazards?
5. What is tephra, and what can be done to mitigate the effects of tephra-fall?
6. What methods are being used at many of the world's active volcanoes in an attempt to predict volcanic eruptions?
7. What information is required to construct volcanic hazards-zonation maps and what are the purposes of such maps?
8. Give examples of relatively recent volcanic eruptions where volcanic hazard-zonation maps have been used in mitigation and preparedness planning, and comment, specifically, on how they were used.
9. Devise a single diagram to describe the relationships that exist between (a) global tectonic setting, (b) type of volcano, (c) volcanic eruption style, and (d) types of volcanic events. Use real-life examples to illustrate your diagram.
10. There are several documented examples of recent volcanic eruptions having affected global climate. Specifically, how can volcanic eruptions influence global climate?
11. What evidence exists to demonstrate that eruptions in pre-historic times (prior to documented records) have also affected global climate?