A volcano is a mountain that opens downward to a reservoir of molten rock below the surface of the earth. Unlike most mountains, which are pushed up from below, volcanoes are vents through which molten rock escapes to the earth's surface. When pressure from gases within the molten rock becomes too great, an eruption occurs. Eruptions can be quiet or explosive. There may be lava flows, flattened landscapes, poisonous gases, and flying rock and ash that can sometimes travel hundreds of miles downwind.

Because of their intense heat, lava flows are great fire hazards. Lava flows destroy everything in their path, but most move slowly enough that people can move out of the way.

Fresh volcanic ash, made of pulverized rock, can be abrasive, acidic, gritty, gassy and odorous. While not immediately dangerous to most adults, the acidic gas and ash can cause lung damage to small infants, to older adults and to those suffering from severe respiratory illnesses. Volcanic ash also can damage machinery, including engines and electrical equipment. Ash accumulations mixed with water become heavy and can collapse roofs. Volcanic ash can affect people hundreds of miles away from the cone of a volcano.

Sideways directed volcanic explosions, known as "lateral blasts," can shoot large pieces of rock at very high speeds for several miles. These explosions can kill by impact, burial or heat. They have been known to knock down entire forests.

Volcanic eruptions can be accompanied by other natural hazards, including earthquakes, mudflows and flash floods, rock falls and landslides, acid rain, fire, and (under special conditions) tsunamis.



Volcanoes sleep for many years, but when one of them awakens, there are big explosions of gases, rocks, and lava into the atmosphere. This type of explosion is called a volcanic eruption.

Volcanoes are found all over the Caribbean region. Although your area may have no active volcanoes, you can still be affected by the volcanic ash and dust from volcanoes in other parts of the region. Ash and dust move with the wind and can be blown onto your country from many miles away.

    • If you happen to be on an island with an active volcano, do not visit the volcano when it is in a state of activity. You could be killed by a sudden explosion!


    • If volcanic ash is falling from the sky, stay inside the house and close all doors and windows.


    • Look out for flying rocks.


  • The most recent volcanic eruption in the Caribbean has been on the island of Montserrat, where a volcano located in the Soufriere Hills awoke on July 18, 1995. People had to leave their homes and go to live on other islands where it was safe.

Did you know?

There are more than 600 volcanoes in the world. About 80 of them are under the sea. The volcano Krakatoa in the East Indies exploded in 1883. The sound was heard 5000km away in Australia.