Yellowstone geyser water Old Faithfull Norris Lower Basin

Location: Yellowstone National Park. Wyoming. US

This picture was taken in an area of Yellowstone called Upper Geyser Basin. This area of approximately two square miles contains the largest concentration and nearly one quarter of all of the geysers in the world. Over 200 geysers in just a couple of square miles!

The place looks out of this world, containing spouting geysers, colorful hot springs and steaming fumaroles.

The Upper Geyser Basin is the home of Old Faithful, the most famous and celebrated geyser in the world. Old Faithful was named in 1870 during the Washburn-Langford-Doane Expedition and was the first geyser in the park to receive a name. It has frequent and regular eruptions (once approximately every 90 minutes) over 30 meters (100 feet).
That big geyser far away on the background of the picture, expelling a big column of smoke, is Old Faithful. 

How Geysers work?

Geysers are hot springs with constrictions in their plumbing, usually near the surface, that prevent water from circulating freely to the surface where heat would escape. The deepest circulating water can exceed the surface boiling point (199°F / 93°C). Surrounding pressure also increases with depth, much as it does with depth in the ocean. Increased pressure exerted by the enormous weight of the overlying water prevents the water from boiling. As the water rises, steam forms. Bubbling upward, the steam expands as it nears the top of the water column. At a critical point, the confined bubbles actually lift the water above, causing the geyser to splash or overflow. This decreases pressure on the system, and violent boiling results. Tremendous amounts of steam force water out of the vent, and an eruption begins. Water is expelled faster than it can enter the geyser's plumbing system, and the heat and pressure gradually decrease. The eruption stops when the water reservoir is depleted or when the system cools.

The first geyser in the photograph has just erupted and ejected all its water (the water can still be seen on the surroundings), and now it is just expelling steam. The other one behind is heating up and the surface is already bubbling. It will erupt shortly!

Here you can see other cool photographs of Yellowstone