Volcanoes both harass and help mankind. As dramatically demonstrated by
the catastrophic eruption of Mount St. Helens on May 1980 and of
Pinatubo in June 1991, volcanoes can wreak havoc and devastation in the
short term. The types of volcanic and associated hazards are not
described in this booklet but treated in several of the publications
listed in _Suggested Reading_. However, it should be emphasized that the
short-term hazards posed by volcanoes are balanced by benefits of
volcanism and related processes over geologic time. Volcanic materials
ultimately break down to form some of the most fertile soils on Earth,
cultivation of which fostered and sustained civilizations. People use
volcanic products as construction materials, as abrasive and cleaning
agents, and as raw materials for many chemical and industrial uses. The
internal heat associated with some young volcanic systems has been
harnessed to produce geothermal energy. For example, the electrical
energy generated from The Geysers geothermal field in northern
California can meet the present power consumption of the city of San
Francisco.
The challenge to scientists involved with volcano research is to
mitigate the short-term adverse impacts of eruptions, so that society
may continue to enjoy the long-term benefits of volcanism. They must
continue to improve the capability for predicting eruptions and to
provide decision makers and the general public with the best possible
information on high-risk volcanoes for sound decisions on land-use
planning and public safety. Geo-scientists still do not fully understand
how volcanoes really work, but considerable advances have been made in
recent decades. An improved understanding of volcanic phenomena provides
important clues to the Earth’s past, present, and possibly its future.