Something is causing the Yellowstone Supervolcano Caldera to stir in its sleep.
A swarm of some 200 earthquakes has been detected beneath the slumbering giant since Feb. 8. The number of accompanying tremors is countless.
**Learn More**
Seismologists Warn Catastrophic Yellowstone Eruption Imminent:

Catastrophic Earthquake fears mount as earthquake cluster strikes Pacific Ring of Fire: