Q:

What is an active volcano?

A:

Quick Answer

An active volcano is one that has had at least one eruption in the past 10,000 years. An active volcano can be dormant or erupting.

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What is an active volcano?
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Scientists use different terms to classify volcanoes. An erupting volcano is one that is having an eruption. A dormant volcano is an active volcano that is supposed to erupt again. An extinct volcano is one that has not erupted in the last 10,000 years and is not expected to erupt again.

There are around 500 active volcanoes throughout the world. Between 50 and 70 of these erupt each year and 160 have erupted in the last 10 years. Approximately 550 volcanoes have erupted since the beginning of recorded history and some of these are now extinct.

Generally, when speaking of volcanoes, geologists don't include those that are underwater. Scientists believe more than 75 percent of the lava that reaches the Earth's surface happens underwater.

Active volcanoes show signs of unrest or are currently erupting. A volcano is classified as extinct when the lava supply in the magma chamber of the volcano dries up. However, on occasion, extinct volcanoes will erupt.

Single active volcanoes may be part of long volcanic fields that can be hundreds of miles long.

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Related Questions

  • Q:

    What is an extinct volcano?

    A:

    An extinct volcano is one that has not erupted in at least 10,000 years and is not expected to erupt in the future, according to Oregon State University. There can be confusion between dormant and extinct volcanoes, but the difference between the two is that a dormant volcano may erupt even if it is in the distant future.

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  • Q:

    How does a volcano form?

    A:

    A volcano forms when a vent in the Earth's crust allows magma to well up from below. The magma fills a void underneath the surface, and when it builds up enough pressure, it bursts through to the surface. As the magma cools, it hardens into rock, and multiple eruptions may build up the mountainous form of a volcano.

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  • Q:

    What is an inactive volcano?

    A:

    An inactive volcano is one that could erupt but has not erupted for more than 10,000 years. Inactive volcanoes are also called dormant or sleeping volcanoes.

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  • Q:

    How is a volcano made?

    A:

    A volcano is any place where magma from the Earth's interior breaks through its surface, as explained by How Stuff Works. Magma is molten rock that is partially liquid, partially solid and partially gaseous. Interaction between the plates that form the Earth's crust is one of the primary catalysts for creating magma.

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