Most tourists who visit Yellowstone National Park snap photos of Old Faithful and stroll past bubbling mud pots, never realizing they're walking on top of one of Earth's most powerful geological ...

A caldera—like the one at Yellowstone Park spanning parts of Wyoming, Idaho and Montana—is a large depression or hollow formed when a volcano erupts and the magma chamber beneath it empties, leading ...

My friend Melanie loves to watch the Discovery Channel and share what she has watched with others. The problem is she can never get the story straight. Her latest tale is about Yellowstone Park ...

A gigantic bulge in the north rim of the Yellowstone caldera is the latest sign of volcanic activity in the national park. Geologists call this type of bulge “volcanic uplift.” It’s often caused by ...