PREDICTING VOLCANIC ERUPTIONS
1. Study of past eruptions from records and observations.
2. Seismographic monitoring. Rising magma sets off earth tremors. When the frequency
and intensity of these begins to increase, the magma is approaching the surface.
3. Tiltmeters measure changing ground shape.
4. Measuring gas and steam emissions using correlation spectrometers. Increasing
emissions of hydrogen sulphide and hydrogen chloride may indicate an eruption is
likely.
5. Increased temperature in a crater lake may suggest magma is nearer the surface.
6. Magnetic anomalies
7. Gravity anomalies
8. Electrical anomalies
Why is volcanic hazard prediction more likely to occur in countries like the United States
and Japan than in Central Africa or Latin America?
What signs do you think local people might recognise as suggesting the mountain is about
to erupt?
PATH OF A KILLER VOLCANO
This video is about Mount Pinatubo in the Philippines. Although the Philippines is an
LEDC, the volcano was well-monitored because the Americans had a large air force base
close by.
1. List the ways in which the volcano was being monitored.
2. Record the events of the following dates
28th May
31st May
2nd June
3rd June
5th June
6th June
7th June
LEVEL 4 DECLARED
8th and 9th June
10th June
12th June
14th June
15th June
Following days
3. How many casualties were there?
4. What other effects did the people suffer?
5. What effect did the eruption have on global climates?