Volcano - Wikipedia A volcano is commonly defined as 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 | Definition, Types, Facts | Britannica 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 solidified lava and volcanic debris near the vent
About Volcanoes | U. S. Geological Survey - USGS. gov 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
Volcanic Eruptions - Volcanoes, Craters Lava Flows (U. S. National . . . Volcanic activity includes earthquakes caused by magma movement, gas emissions, effusive emissions of lava, and cataclysmic eruptions Most geologists use the term eruption to encompass a whole period of volcanic activity which is bracketed by quiet intervals
Volcano facts and information | National Geographic 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
What Causes Volcanic Eruptions? An In-Depth Guide 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 magma, buoyant and restless, seeks a way to rise When it does, we witness one of nature’s most extraordinary spectacles Magma: The Fire Within
Volcanoes - Education | National Geographic Society 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 long time but may erupt at a future time Extinct volcanoes are not expected to erupt in the future
Volcano facts and types of volcanoes | Live Science Volcanoes are cracks in Earth's crust that allow molten rock and hot gases to escape According to the U S Geological Survey (USGS), there are about 1,350 volcanoes worldwide that have the