Yellowstone National Park sits atop one of Earth’s largest volcanic systems, and right now that system is slowly reshaping the ground. Instruments show that the Yellowstone caldera is inflating into a ...

There appears to be a massive bulge forming along Yellowstone's caldera, indicating activity within the supervolcano's magma chamber.

The bulge first appeared in 1996 and has now returned, but Yellowstone Volcano Observatory says there's no cause for alarm.