NOVA ScienceNOW - Midwest Earthquakes!

Scientists have a good idea of what causes earthquakes in places like California. It's all about sudden movement along the edges of the giant crustal plates that make up the Earth's crust. But another kind of quake exists, one that occurs far from plate boundaries. It's big, it's dangerous, and as I found out, it could strike anytime in the very middle of America.

[@iipixel8607]

Meh probably aliens under the ground..