GEOLOGY

Detailed explanation-1: -Volcanoes are classified as active, dormant, or extinct. Active volcanoes have a recent history of eruptions; they are likely to erupt again. Dormant volcanoes have not erupted for a very long time but may erupt at a future time. Extinct volcanoes are not expected to erupt in the future.

Detailed explanation-2: -Extinct → Extinct volcanoes are those which have not erupted in human history.

Detailed explanation-3: -Volcanoes are classified by the eruption type and by the volcanic cone shape. There are three basic cone shapes and six eruption types. The three cone shapes are cinder cones, shield cones, and composite cones or stratovolcanoes.

Detailed explanation-4: -Volcanoes go dormant because magma from the Earth’s mantle can no longer reach the volcano. For example, in Hawaii, the line of islands are slowly moving to the northwest. Meanwhile, the supply of magma stays in the same place within the Earth, which currently happens to lie beneath the Big Island.

Detailed explanation-5: -Volcanologists use that term as shorthand for “potentially active, ” so a “dormant” volcano is one that is not erupting now, but that is considered “active” because it could erupt in the future. Mount Hood is an active volcano that is currently dormant. Kīlauea is an active volcano that is currently erupting.