A common question particularly asked by those students looking for science fair ideas. Geyser experiments are described on my science fair project page in the student section of this site. All of the experiments listed need adult supervision. PLEASE BE SAFE.
The word geyser is an eponym. Find out the origin of the word and what an eponym is on my page, How Geysers Got Their Names.
Geysers are temporary features geologically. The do not last for millions of years but probably for a few thousand. Geysers require a specific set of geological conditions. First, heat from a magma (molten rock) very near the earth's surface. Second, a supply of water that can circulate deep enough to be heated by the magma. Third, cavities or pore space in the rocks just below ground level that can act as a pressure chamber. Fourth, silica rich rocks that will provide abundant silica to seal the pressure chamber and keep the pressure contained until a eruption results. Geologically, having all four of these conditions at once is a relatively rare occurrence.
This is not as easy as a question as it first might seem. Yellowstone contains around 500 geysers, over half of the known geysers in the world. However, geysers are unstable as a rule and counting them is difficult. Some destroy themselves or are destroyed by man. Some go extinct. Some may be inactive for long period and then erupt. Some erupt frequently. Some hot springs which have not shown any geyser activity will suddenly erupt. Do you count all that have ever erupted? How do you know if a geyser is dormant or extinct? How many hot springs have plumbing systems that could act as a geyser if conditions are right but have nor erupted when it could be observed by man? These factors make an exact count impossible.
Back to Top
Another difficult question. It depends on what your definition of large is. Is it the geyser with the greatest eruptive height? Is it the geyser with the largest discharged volume of water during an eruption? Is it the geyser with the widest column of water? Does the geyser need to be capable of eruptions or do you want to consider extinct geysers which have been naturally destroyed? The answer will depend on what you want to consider. For a discussion of what is the largest geyser and a list of the world's tall geysers go to my Tall Geysers Page.
The short answer is NO. They are too hot and even if you survived, it is against the law. Since thermal areas bring to mind spas and bath houses this is a popular question. Because this question is so common I have created a page on swimming in Yellowstone.[
For the answer, follow this link HOW DO GEYSERS WORK?
For answer, follow this Link
The heat needed for geyser formation comes from liquid rock or magma when it is near the surface of the earth. That is why geysers and volcanoes are found in the same area. When the magma reaches the surface, a volcano is formed. On the surface the liquid rock is called lava.
Geysers, though rare, are found in the same geologic settings where volcanic heat sources are available. All volcanic areas do not have geysers, however. Geysers require a specific set of conditions in order to form. Other thermal features such as fumaroles and hot springs are common in volcanic areas and can also be heated by near surface magma bodies.
The heat comes from a buried magma ( molten rock) chamber less than 2km below the surface. The magma is the source of much of the volcanic rocks in Yellowstone. The major eruption which formed the Yellowstone caldera was about 600,000 years ago and spread wind born ash as far away as Louisiana. The area is considered by some geologists to have potential for additional eruptions, though, there have been none during recorded time.
The smell is from trace amounts of hydrogen sulfide gas, sometimes called "rotten egg gas". In larger concentration it is a poisonous gas but
concentration in the Yellowstone steam are small and stinky. Hydrogen
sulfide is one of several gases emitted in Yellowstone that rise through
cracks from the buried magma (molten rock) in the Yellowstone caldera (a collapsed volcano).
A geyser eruption starts as the cooler water at the surface reaches the boiling point. The boiling point of a liquid is dependent upon the pressure. The boiling point of pure water 212 degrees Fahrenheit (100 degrees Celsius) at sea level. In Yellowstone the elevation is about 7,500 feet, the pressure is lower, and the boiling point of water is only about 199 degrees Fahrenheit (93 degrees Celsius). The rising water coming from the volcanic source at depth is superheated to temperatures well above 200 degrees. At the surface most geysers are 199 to 215 degrees Fahrenheit which is at or just above the boiling point just before and during an eruption. For geysers to erupt the water must be at or above the boiling point.
It is not known exactly when the first geyser in the world was found. The first known reference to geysers is a short phrase in Homer's Iliad that refers to a spout of water from a spring. This is thought to be a reference to a geyser in Turkey. One such spring, Gayser Suyu, is known to have existed near the site of Troy. The first references to Geysir, a geyser in Iceland, was made in 1294. The Geysers in Yellowstone were certainly known to the Native Americans of the area although when they were discovered is not known. European explorers heard legends of thermal features as they encountered the Native Americans in the late 1700's and early 1800's. The geysers were not viewed by European explorers until the early 1800's. (See the next Question)
Return to Wyo's Geyser Page