On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater.

Nov 26, 2025 · 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 …

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.

Apr 17, 2023 · Eruptions of lava, ash, volcanic bombs, blocks, and cinders form new land on oceanic islands, and build towering and inspiring snow-covered peaks. Volcanic eruptions are …

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

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...

Dec 13, 2025 · Explore the geological processes behind volcano formation and activity, why volcanoes matter, their hazards, resources, and major global examples.

Dec 16, 2025 · The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards …

Feb 25, 2025 · 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.

Jun 13, 2025 · It is within the mantle, especially in its upper regions, that most volcanic activity is born. Here, temperature and pressure conspire to partially melt rock, forming magma. This …