Geysers and Hot Springs

Geysers and hot springs are created by water heated deep underground. Hot springs are pools of naturally warm water. Geysers are more dramatic, shooting hot water and steam high into the air. Both are found in areas with volcanic activity.

How Geysers Work

Underground, water seeps down to hot rocks heated by magma. The water gets superheated under pressure. When the pressure builds up enough, the water shoots up through a crack in the ground. This creates a dramatic eruption of steam and boiling water. Then the cycle starts over.

Famous Geysers

Old Faithful in Yellowstone National Park is the most famous geyser. It erupts about every 90 minutes, shooting water up to 180 feet high. Yellowstone has more geysers than anywhere else on Earth. Iceland also has many geysers, and the word geyser actually comes from an Icelandic word meaning 'to gush.'

Fun Facts

• Old Faithful erupts about every 90 minutes and has done so for thousands of years.
• Yellowstone has about 500 geysers, more than half of all the geysers on Earth.
• The water in some hot springs can be over 200 degrees Fahrenheit.

Did You Know?

Some hot springs are home to special bacteria that love extreme heat. These colorful bacteria create the rainbow rings you see around hot springs in Yellowstone!