As the world's largest hydrothermal system, Yellowstone National Park is a volatile landscape. Volcanic activity has occurred here for some 2 million years. Today, earthquakes are evidence of continuing activity that is closely monitored by the park and the U.S. Geological Survey.
The hot spot below Yellowstone has moved northeast during the last 16 million years, from the Oregon-Idaho-Nevada border through southern Idaho to the northwest corner of Wyoming.
Three volcanic cycles created the Yellowstone Plateau volcanic field. The first was 2.1 million years ago; the last was 640,000 years ago.
Yellowstone's geysers, hot springs and mud pots are evidence of heat beneath the surface. The Yellowstone caldera offers some 10,000 thermal features.
Yellowstone's volcano is not dormant. In addition to active thermal features, ground deformation and earthquakes prove it is still active.
Although earthquakes occur quite often in the caldera, experts say Yellowstone is not likely to erupt violently in the near future.
Article Written By Kelly Aspen
Kelly Aspen's writing focuses on natural places, cultural sites and wildlife. She has more than 10 years of experience as an editor and writer for various magazines, books and websites.