4 days ago · 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 …

Jan 2, 2026 · A volcanic eruption is an eruption of molten rock, hot rock fragments, and hot gases through a volcano, which is a vent in a planet’s or satellite’s crust. Volcanic eruptions can cause …

Volcanology deals with the formation, distribution, and classification of volcanoes as well as with their structure and the kinds of materials ejected during an eruption (such as pyroclastic flows, lava, dust, …

Dec 31, 2025 · Volcanism, any of various processes and phenomena associated with the surficial discharge of molten rock, pyroclastic fragments, or hot water and steam, including volcanoes, …

There are more than 700 known volcanoes classified as stratovolcanoes, many more than any other volcanic formation. Several are among the best-known volcanoes because of their striking …

3 days ago · Volcanoes are frequently classified by their size and shape (as is described in the section Volcanic landforms), but they can also be classified by their eruptive habits.

Nov 26, 2025 · Many active volcanoes are located in the so-called “ Ring of Fire ” made up of island arcs and mountain ranges bordering the Pacific Ocean (see the map). The concept of seafloor spreading …

Nov 26, 2025 · Volcano - Calderas, Magma, Eruptions: Most calderas—large circular or oval depressions more than 1 km (0.6 mile) in diameter—have been formed by inward collapse of …

4 days ago · Volcano - Lava, Gas, Hazards: The list of hazards associated with volcanic eruptions is long and varied: lava flows, explosions, toxic gas clouds, ash falls, pyroclastic flows, avalanches, …

Volcanoes are closely associated with plate tectonic activity. Most volcanoes, such as those of Japan and Iceland, occur on the margins of the enormous solid rocky plates that make up Earth’s surface.