Yellowstone Volcano Grows

Forces brewing deep beneath Yellowstone National Park could be making one of the largest volcanoes on Earth even bigger, a new study reveals.

In the past decade, part of the volcano has risen nearly five inches, most likely due to a backup of flowing molten rock miles below the planet's crust.

While the rise may not be noticeable to the casual hiker, the activity may have cracked the crust in the park's famous Norris Geyser Basin (NGB), leading to the formation of new fumaroles—holes that vent smoke and gas—and the reawakening of some of the area's geysers, including Steamboat, the largest geyser in the world.

Yellowstone last erupted about 640,000 years ago, spewing 240 cubic miles of material. Despite the newly discovered activity, researchers don't expect it to erupt any time soon. Eventually, however, it could explode again as a super-volcano that would destroy life for hundreds of miles around and coat the entire country in ash. →