Volcanic eruptions

Science

Definition

Events in which magma, gases, and ash are expelled from a volcano onto Earth's surface or into the atmosphere. Eruptions occur when pressure from dissolved gases in magma exceeds the strength of the overlying rock, and they range from gentle lava flows to explosive blasts.

Examples

  • The 1980 eruption of Mount St. Helens that blew off the mountain's north face in a lateral blast
  • Hawaii's Kilauea producing slow-moving basaltic lava flows that reach the ocean
  • The 1991 Mount Pinatubo eruption cooling global temperatures by about 0.5°C for two years due to sulfur aerosols

Related Terms

Plate boundaries Tectonic plates Lava types Hot spots

Study This Concept

Practice volcanic eruptions with free review games in these units:

Earth Science Unit 3: Volcanoes and Mountains