The city of Mammoth Lakes sits on the edge of the Long Valley Caldera formed around 700,000 years ago. This caldera is 15 miles in diameter and is North America's second largest. 1. The Long ...

The Long Valley Caldera, one of the largest volcanic systems in the U.S., has been shaking and rising, with over 2,000 earthquakes detected in just six months. But here’s the twist—it’s not ...

Three supervolcanoes that are more dangerous than Yellowstone and could wipe out the entire planet. Earth is hiding the ...

The Long Valley Caldera in northern California is waking up, and scientists are monitoring it. This supervolcano, whose last blast was some 100,000 years ago, isn’t leading up to another monstrous ...

Beneath the Earth’s surface are ticking time bombs ... The second supervolcano is the Long Valley Caldera in eastern California, which last erupted approximately 100,000 years ago.