Mt. Pinatubo Overview
The goal of this exercise is to get you to think about the very real links between geology and society. Mount Pinatubo in the Philippines erupted spectacularly in 1991 - it was the second largest eruption of the 20th century. The video that we will watch on Friday details the monitoring and prediction efforts of US Geological Survey (USGS) volcanologists and their colleagues at the Philippine Institute for Volcanology and Seismology (PHIVOLCS). Thousands of lives were saved because geologists were able to accurately predict the timing and magnitude of the eruption - the Mt. Pinatubo eruption is considered one of the greatest success stories of modern volcanology. As further evidence of its impact on our culture, consider that the movie Dante's Peak draws much of its scientific inspiration from the story portrayed in this video.

For further surfing...

• PHIVOLCS Mt Pinatubo Page
• USGS Factsheets:
  • Cataclysmic 1991 Eruption of Mount Pinatubo
  • The Devestating Lahars that followed the eruption.
  • The Value of USGS Volcano Hazards Research and Monitoring.
  • Types of Volcanic Hazards.
  • Other USGS Volcano Fact Sheets
• USGS Photo Glossary of Volcanic Terms
• NOVA Online at PBS Online

The Assignment
You will be answering the following questions on Friday (3/15) while watching the video in class. It will help if you've done the background surfing above and read over the questions below before coming to class on Friday.

1. What type of volcano is Mt. Pinatubo? What composition would you expect its magma to be? What types of igneous rocks would you expect it to produce?
2. What precursory geologic phenomena suggested that an eruption was possible?
3. What scientific instruments were used to monitor the volcano and what did each measure?
4. How did USGS volcanologists balance the demands of keeping the civilian and military authorities informed with the inherent scientific uncertainties of predicting volcanic behavior? How did the civilian and military authorities react to the scientific assessments of the situation?
5. What happens when volcanic eruptions occur without warning or when warnings are ignored? What happens when a warning is issued but no volcanic eruption occurs?
6. At what point would you have ordered the evacuation of Clark Air Base?
7. What aspects of a Mt. Pinatubo-style eruption caused the most serious threat to life and property? How might these risks have been avoided or mitigated?

This Exercise is "Homework #8" and will be collected on Friday (3/27) at the end of class.