Volcanoes have different stages of activity. An active volcano is one that is erupting or showing signs of erupting soon. A dormant volcano has not erupted for a while, but is expected to erupt in the future. An extinct volcano will probably never erupt again.
2. Monitoring Volcanoes
Geologists use a variety of technical instruments to study volcanoes and predict eruptions. Earthquakes, increases in ground temperature and escaped gases provide warning signals of potential eruption.
3. Destruction Caused by Volcanoes
Volcanoes can cause widespread damage. Huge clouds of ash may bury towns, and volcanic gases can be deadly. A lava flow covers everything in its path and can start fires and landslides.