Geyser is a hole in earth surface that shoots hot water and steam. Geyser is a rare geological phenomenon. Geyser usually located near active volcano site because it is an effect of magma. There are about 1000 active geysers in earth and half of them located in Yellowstone National Park, Wyoming, USA.
Geyser is an extremely rare feature. It needs to fulfill some condition so the geyser can shoot water. It is a coincidence that the geological structure of the area meets the condition to form geyser. Some conditions required for a geyser is hot rocks below (magma), sufficient groundwater surface, at least a subsurface reservoir, and fissure to deliver water to the surface. A fissure is a long deep crack in the body of the earth that allows water to flow.
Eruption of geyser happen if groundwater is superheated. The eruption is mainly caused by steam explosion. Magma activities inside earth caused water is boiling. After water is boiled, it always tries to change it formation from liquid to gas just like how we learn in science. However, it needs more space to transforming from liquid to gas. As we know, the distance between particles in liquid form is big (the particle is far from each other in gas form) while in form of liquid it is not too far but not close either. The volume expands 1600 times to transform from liquid to gas. When the magma activity is high, it boils lot of water. The water wants to transform but they can’t. So it will increase the pressure and BOOM! The steam explodes causing hot water fountain.
Magma always does activities. That’s why there are some geysers that erupt periodically. Usually the geyser is a small geyser or the geysers located near the magma so it has more heat. Some other – like the bigger one – need high activity of magma to explode. For some other that irregularly explode there is always boiling water in the geyser, can be seen by steam that always come out from the vent. But, to explodes it needs more energy. It is a sign that the magma is active and it may signals us that the volcano is in high activity that in some way could lead to volcanic eruption.
The most popular geyser is Old Faithful Geyser in Yellowstone National Park. It is popular because its periodical eruption, height, and duration. Old Faithful’s eruption is about 1.5-5 minutes with height between 100-200 feet (30-60 meter) and it erupts every 60-90 minutes. The interval between eruptions that take 60-90 minutes classified as quick. Some other geysers erupt every certain hour, day, week, or even irregularly. In every eruption, the geyser shoots about 14-32 kL hot water. Researchers said that the interval between eruption of Old Faithful is increasing. They predicted that it caused by the reducing water supply in underground.
World tallest geyser named Steamboat. It is located in Yellowstone National Park too. Its last eruption is in 3 September 2014. The eruption takes more than 10 minutes. The fountain height reach more than 300 feet (approximately 100 meters).
There is a geyser in Indonesia. It is called as Cisolok Geyser since it is located in Cisolok, near Pelabuhan Ratu, Sukabumi. However, the geyser is small. It shoots water continuously. Even though the geyser is small, people are directed not to stand very close to the geyser because it can harm us.