A mudline left behind on trees shows depths reached by the mud. Scale indicated by scientist- center far right. Click here to see a chart of volcanic hazards. Keep in mind that hazards such as volcanic eruptions become natural disasters only when humans get in the way. A primary focus of volcanology is to provide scientific and educational information that can lead to hazard mitigation.
Scientists assess volcanic hazards based on a volcano's past behavior.
They carefully monitor volcanoes for signs of restlessness and inform the public about possible dangers. Scientists have helped to save thousands of lives and millions of dollars worth of property throughout the world. For instance, mapping studies of Mount Rainier indicate a history of large-scale debris flows. The last giant debris flow swept down Mount Rainier's western slopes about 500 years ago. Since future eruptions would probably follow a similar pattern, monitoring of the volcano is crucial because of the large number of people who would now be at risk.