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How hot are volcanoes?

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In general, the magma (molten rock) in volcanoes ranges from...




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Welcome to CoreFacts, where we're always short on time and big on science. I'm Jessica Robertson. Today's question is...

How hot are volcanoes?

In general, the magma (molten rock) in volcanoes ranges from 800 to 1200 degrees Celsius, depending mostly upon composition. Steam and gas vents on active volcanoes range from boiling temperature up to the temperature of magma. Often there are also springs low on the flanks of volcanoes that discharge water from slightly warm to boiling.

As you can imagine, lava sampling can be risky, but it is important to do it as hot lava samples provide important information about what's going on in magma chambers.

And now you know. Join us again every week for a new CoreFact. For other CoreFacts or for CoreCast, our in depth science podcast, go to If you'd like to have questions featured on our show, give us an email at or a phone call at 703-648-5600. Remember, long distance fees do apply.

The USGS CoreFacts is a product of the U.S. Geological Survey, Department of the Interior.

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