Only 14 states require them. Hidden magma cap discovered at Yellowstone National Park Ranking All-You-Can-Eat Chain Buffets From Worst To First The world's biggest companies have caused $28 ...

Geoscientists discovered a magma cap acting as a "lid" 2.4 miles beneath Yellowstone. This magma cap traps heat and pressure, but also allows gas to vent, reducing eruption risk. Seismic imaging ...