Volcanoes Fast Facts

Facts:More than 80% of the Earth’s surface, both above and below sea level, was formed by volcanoes.

Lava is molten rock from a volcano that has reached the Earth’s surface.

Molten rock below the Earth’s surface is referred to as magma.

Volcanoes are generally classified into four main types:
Cinder cones – the most common volcanoes, steep conical hills with a vent and a crater at the summit, usually no more than 1,000 feet high.
Examples: Sunset Crater Arizona, Lassen Peak in California, and San Quintin Volcanic Field in Baja, Mexico.

– Composite volcanoes or stratovolcanoes – symmetrical, cone-shaped, and have a conduit system through which magma flows to the surface through one or more vents, can reach 8,000 feet in height.
Examples: Mount St. Helens, Mount Fuji, Redoubt, Pinatubo, Soufriere Hills and Mount Pelée in Martinique.

August 8, 1991 – Cerro Hudson in Chile erupts. (VEI 5)

March 20, 2010 – The volcano Eyjafjallajokull erupts in Iceland for the first time since an eruption in the early 1820s. (VEI 4)

April 14-21, 2010 A stronger eruption of Eyjafjallajokull expels an ash cloud 30,000 feet into the air, shutting down airports in northern and western Europe for a week. The International Air Transport Association (IATA) estimates that the work disruption due to volcanic ash cost the airline industry $1.7 billion in revenue. (VEI 4)

February 1, 2014 – Mount Sinabung in Indonesia, which has been spewing gas since September, erupts, killing at least 14 people.

September 27, 2014 – Mount Ontake in Japan erupts suddenly, engulfing hikers in an ash cloud. At least 57 people are killed.

CNN