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Introduction

A volcano is a location where magma, or hot melted rock from within a planet, reaches the surface. It may happen violently, in a massive supersonic explosion, or more quietly, as a sticky, slow lava flow.

Volcanoes have been a part of earth's history long before humans. Compare the history of human beings, a few million years in the making, to that of the Earth, over four billion years in the making.

Volumes of Some Well-Known Volcanic Eruptions

  Eruption                      Date           Volume in km^3
  --------                      ----           --------------
  Paricutin, Mexico             1943                 1.3
  Mt. Vesuvius, Italy           79 A.D.               3
  Mount St. Helen, Washington   1980                  4
  Krakatoa, Indonesia           1883                 18
  Long Valley, California     pre-historic       >450 & <700
  Yellowstone, Wyoming        pre-historic           2400

Volcano Web : Introduction

created by Lorrie Lava, lava@pele.bigu.edu
Volcanic Studies, Big University

last modified: April 1, 1995

URL: http://www.bigu.edu/web/intro.html