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.

When it does reach the surface, however, a volcano is formed. Thus subduction zones are bordered by chains of volcanoes called volcanic arcs. Typical examples are the volcanoes in …

Oct 15, 2025 · Our mission is to provide uninterrupted, real-time updates whenever an earthquake strikes or a volcano erupts — and your donations make this possible. Every contribution, big or …

Sep 29, 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. A volcanic eruption is an …

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...

The most well-known types of volcanoes are cinder cones, composite volcanoes (stratovolcanoes), and shield volcanoes. The illustration below provides an example of the …

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 …

Feb 25, 2025 · Discover interesting facts about volcanoes, including why and where they form and history's deadliest eruption.

5 days ago · Volcanoes are nature's most dramatic rocks, and while their eruptions can be awe-inspiring, they also pose serious threats to nearby communities and global climates. Mount …

Jul 31, 2025 · There are about 170 potentially active volcanoes in the U.S. The mission of the USGS Volcano Hazards Program is to enhance public safety and minimize social and …