Volcanic Eruptions

A volcanic eruption occurs when molten rock, ash and steam pour through a vent in the earth's crust.

Volcanoes are described as active (in eruption), dormant (not erupting at the present time), or extinct (having ceased eruption; no longer active). Some volcanoes explode. Others are slow-flowing fountains of lava, which is hot fluid rock.

The following are examples of famous volcanic eruptions.

• Where: Italy
• When: A.D. 79
• The eruption of Mount Vesuvius buried the towns of Pompeii and Herculaneum under 20 feet of ash and lava, killing an estimated 20,000 people. The ash that buried the town and the people also preserved them. The work of uncovering the ancient cities began in 1748 and continues to this day.

• Where: Indonesia
• When: 1883
• The greatest explosion in modern times occurred when Krakatoa erupted. The power of the explosion was thought to be 26 times the power of the greatest H bomb, and the roar was heard over one-thirteenth of the surface of the earth. The eruption wiped out 163 villages, killing 36,380 people.

For a list of other volcanic eruptions, see Recent Volcanic Activity and Earthquakes and Volcanic Eruptions at Infoplease.com.

For other information on volcanoes, see also Volcanoes of the World, The Nature of Volcanoes, Principal Types of Volcanoes, Types of Volcanic Eruptions, and Earth's Greatest Volcanic Field.