Yellowstone National Park is among the most studied geological wonders on Earth with over 10,000 geothermal features in it’s boundaries, more than half of the total features on the planet. All of this thermal activity is fueled by the third largest supervolcano on earth, the Yellowstone Caldera, which lies beneath the park’s central region. The volcanic hotspot beneath the surface functions much the same way as the one that formed the Hawaiin Islands, melting the bottom of the tectonic plate as it passes above the stationary hotspot, but instead of the conical volcanoes that deposit molten rock to create the islands as we see in Hawaii, Yellowstone’s caldera consists of a much thicker magma that results in periodic explosions. These explosions occur roughly every 600,000-640,000 years and have created the Snake River Plain over the course of the last 17 million years as the North American tectonic plate traverses over it. The largest super volcano on Earth is the La Garita in Colorado, followed by Toba Caldera in Sumatra, with the third largest being the Yellowstone Caldera in Wyoming.

GEYSERS

Old Faithful is among the world’s most famous geysers and gets over 4 million visitors a year to watch this geothermal wonder erupt. Located in Yellowstone’s upper geyser basin, Old Faithful gets it’s name from it’s regular 90 minute eruption intervals where thousands of gallons of superheated water and steam erupt from an underground reservoir through a 5 inch opening below ground, throwing water up to 150 feet into the air.

HOT SPRINGS

The Grand Prismatic Spring is the largest hot spring of it’s kind in the US, third largest in the world at 370 ft in diameter and 160 feet deep. It’s characteristic vibrant colors are a result of thermophiles, which are extremophile microorganisms that can withstand extreme levels of cold, acidity, and in this case heat. The different colors in the springs are created by different species of thermophile that thrive in different temperature ranges and create the concentric colored rings around the hottest part of the spring.

MUD POTS

These unique features are formed when hot acidic water rises up from the ground, dissolving surface rocks into clay forming a soup, of sorts. With temperatures reaching 200 degrees combined with the escaping carbon dioxide and hydrogen sulfide these pools appear to boil and typically give off the pungent aroma of sulfur.

FUMEROLES

The most unstable of the thermal features, fumaroles can be the result of dried up hot springs or can become hot springs should the water table increase. These are the result of subterranean ground water flash boiling on the hot rock below and what we see is the resulting steam venting through channels in the earth.