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]

Jan 8, 2026 · Strictly speaking, the term volcano means the vent from which magma and other substances erupt to the surface, but it can also refer to the landform created by the accumulation of …

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...

May 21, 2025 · 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 …

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.

Jul 10, 2025 · Volcanic eruptions can be divided into two main groups: effusive and explosive. Lava flows and sticky lava that forms bulging domes belong to the effusive type of eruption.

4 days ago · USGS Volcano Observatories release regular updates and notifications to communicate increases or decreases in volcanic activity and explain unusual or hazardous circumstances.