Within Yellowstone National Park, in the states of Wyoming, Montana, and Idaho, in the United States, lie one-half of the earth’s geothermal features. Yellowstone holds the world’s most diverse collection of geysers, hot springs, mud pots, thermal pools, and fumaroles. The more than 300 geysers make up two-thirds of those found on earth. Combined, there are more than 10,000 thermal features within Yellowstone’s boundaries. This natural wonderland contains more geothermal features than any place on earth.
What causes all of this bubbling and spewing? The answer is, of course, hot water. Today’s geothermal activity in Yellowstone is linked to past volcanic activity. The park sits atop a giant caldera. This is a volcano that collapsed due to a cataclysmic explosion over 600,000 years ago. This caldera is what supplies the heat needed for the geothermal features to put on their shows.
Geysers
Easily the most dramatic geothermal features of Yellowstone are the geysers. Geysers are hot springs that erupt periodically, sending plumes of hot water and steam into the air. The ingredients to make a geyser are heat, water, and extremely hard underground rock. Yellowstone has a plethora of these ingredients. They combine to create the dramatic eruptions of these natural fountains.
Hot Springs
Another interesting feature of the park are the hot springs terraces. Hot water combines with limestone to create new land right before your very eyes. The landscape of the travertine terraces changes daily, along with the colors of these stone waterfalls. The beautiful colors of pink, green, brown, yellow, and orange are caused by the bacteria and other organisms living on the rock.
Mudpots
Wearing nose plugs when visiting the mud pots might be a good idea. If vistors can get past the smell of rotten eggs, they can appreciate watching the mud boiling like a pot of stew. The presence of sulfur is what makes mud pots different from hot springs. The sulfuric acid breaks the rock down into clay. The "boiling" is caused by gasses that escape through the layers of mud.
Although they are not as picturesque as thermal pools or as dramatic as geysers, mud pots are another feature that makes Yellowstone unique. Mud pots are points close to major vents, called resurging domes, where the lava flowed through the collapsing caldera. These points are carefully monitored for information about possible volcanic activity.
Thermal Pools
Thermal pools, or hot springs are some of the most beautiful sights in Yellowstone. The water color ranges from a deep sapphire blue to a bright teal in these pools. Many are surrounded by rainbow-colored bacteria. Some erupt gently, sending small waves out from the center. The underground channels are larger than that of geysers, allowing the cooled water to return. This causes them to remain in equilibrium.
Fumaroles
Steam rushes into the air, sometimes creating a hissing sound, via fumaroles. These vents are similar to hot springs, but they have no liquid water. The water that does seep into the ground around the fumaroles is turned to steam by the heat of the underground rock.
These geothermal features, first documented by members of the Lewis and Clark expedition, continue to awe the visitors who witness them. These geological features help to make Yellowstone National Park nature’s magic kingdom.
Patti Hutchison - After teaching special education for 25 years, Patti Hutchison and her husband, Bruce, moved to South Carolina from upstate New York. ...
