A volcano is formed when hot molten rock, ash and gases escape from an opening in the Earth's surface. The molten rock and ash solidify as they cool, forming the distinctive volcano shape shown here. As a volcano erupts, it spills lava that flows downslope. Hot ash and gases are thrown into the air.
Most volcanoes are found along a belt, called the “Ring of Fire” that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called “hot spots."
The volcanoes of the Philippines are produced at the junction of the Philippines tectonic plate and the Eurasian plate. ... Lahars (mud flows) are very common in the Philippines, because the archipelago has often heavy rains. Tsunamis accompany eruptions in the Philippines more often than in any other volcanic region.
Volcanoes are classified as active, dormant, or extinct.
A volcano is currently active if it is erupting lava, releasing gas or generating seismic activity. An active volcano is labelled dormant if it has not erupted for a long time but could erupt again in the future. When a volcano has been dormant for more than 10 000 years, it is considered extinct.
Dormant volcanoes are volcanoes that have not erupted in a long time but are expected to erupt again in the future.
An extinct volcano has not had an eruption for at least 10,000 years and is not expected to erupt again in a comparable time scale of the future.
