The USGS says: “Almost all earthquakes at Yellowstone are brittle-failure events caused when rocks break due to crustal stresses.
“Though we’ve been looking at Yellowstone for years, no one has yet identified ‘long-period (LP) events’ commonly attributed to magma movement.
“If LP events are observed, that will NOT mean Yellowstone is getting ready to erupt. LP earthquakes commonly occur at other volcanoes in the world, including volcanoes in California, that have not erupted for centuries or millennia.”
The Yellowstone supervolcano, located in the US state of Wyoming, last erupted on a major scale 640,000 years ago.
According to the USGS, the chances of a Yellowstone eruption is around one-in-730,000.
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