Volcanoes are openings, or vents where lava, tephra (small rocks), and steam erupt onto the Earth's surface. Volcanic eruptions can last days, months, or even years. What is a volcano? Redoubt volcano with minor ash eruption. Photograph taken during observation and gas data collection flight by AVO staff March 30, 2009.

Volcanoes, based on their frequency of eruption or volcanism, can be defined as either active, dormant or extinct. Active volcanoes have a recent history of volcanism and are likely to erupt again, dormant ones have not erupted in a long time but may erupt later, while extinct ones are not capable of eruption at all.

2025年1月22日 · volcano, vent in the crust of Earth or another planet or satellite, from which issue eruptions of molten rock, hot rock fragments, and hot gases. A volcanic eruption is an awesome display of Earth’s power.

There are more than 1,500 potentially active volcanoes or volcanic areas around the world at any given time. They may be the world’s most dynamic landforms, given their ability to grow by accretion or shatter and collapse during an eruption.

2018年1月15日 · Volcanoes are Earth's geologic architects. They've created more than 80 percent of our planet's surface, laying the foundation that has allowed life to thrive. Their explosive force crafts...

2025年1月14日 · Volcanoes occur when material significantly warmer than its surroundings is erupted onto the surface of a planet or moon from its interior. On Earth, the erupted material can be liquid rock ("lava" when it's on the surface, "magma" …

2022年3月3日 · A volcano is an opening in Earth's crust where magma breaks through, and when erupting can rain down molten rock, ash and gases. There are several types of volcanoes.

List of volcanoes in Djibouti; List of volcanoes in Equatorial Guinea; List of volcanoes in Eritrea; List of volcanoes in Ethiopia; List of volcanoes in Kenya; List of volcanoes in Libya; List of volcanoes in Madagascar; List of volcanoes of Mauritius; In Nigeria all the volcanoes are in the Biu Plateau; List of volcanoes in Réunion; List of ...

A volcano is a vent in Earth's surface where magma, gas, and ash escape. The name is also used for cones of erupted material at the vent. Volcanoes are found on many planets and moons in our solar system.

2025年1月16日 · volcanism, any of various processes and phenomena associated with the surficial discharge of molten rock, pyroclastic fragments, or hot water and steam, including volcanoes, geysers, and fumaroles.