A volcano is a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. [1]

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. The term volcano can also refer to the landform created by …

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.

A volcanic eruption is the expulsion of gases, rock fragments, and/or molten lava from within the Earth through a vent onto the Earth’s surface or into the atmosphere.

Articles, facts, information and photos for volcanoes and volcanic activity. | Geology.com

Jul 10, 2025 · 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...

Jun 17, 2025 · Most volcanoes form at the boundaries of Earth’s tectonic plates. These plates are huge slabs of Earth’s crust and upper mantle, which fit together like pieces of a puzzle. These plates are …

Volcanic "bombs" are chunks of semimolten lava that fly out of a volcano and solidify as they land. They're often flung miles from the volcanic crater.

6 days ago · Volcano Observatory staff monitor, research, and issue formal notices of activity for volcanoes in assigned geographic areas. Scientists also assess volcano hazards and work with …

Our definition includes "single or multiple vents or fissures" which relate to geographic extent. Such features range from individual vents (measured in meters) through volcanic edifices (measured in …