Many volcanoes erupt in very consistant patterns, while other volcanoes have no eruption pattern at all. This makes forecasting eruptions difficult.

What makes predicting eruptions even more difficult is the fact that many volcanoes start with one type of eruption pattern and then change eruption patterns as they grow older.

Some of the most powerful eruptions in recorded time have come from volcanoes that have been dormant for hundreds and even thousands of years.

Here we have geologists studying a tilt meter. A tilt meter is used to measure the growth of the lavadome in the foreground. The tiltmeter will show a different angle as the dome grows. With careful study the geologists can tell if magma is on the rise and that an eruption may occur in the near future.

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