It was not until I visited the Yellowstone National Park – a nearly 3,500-square-mile wilderness recreation atop a volcanic hot spot – that I was able to see up close geysers.
Yellowstone National Park is the world’s first national park. Mostly in Wyoming, the park spreads into parts of Montana and Idaho, too. Aside from geysers, it also features dramatic canyons, alpine rivers, breathtaking lakes and waterfalls, lush forests, and hot springs.
But let’s talk about geysers here. “A geyser is a rare kind of hot spring that is under pressure and erupts, sending jets of water and steam into the air,” the National Geographic defines. “Geysers are made from a tube-like hole in the Earth’s surface that runs deep into the crust. The tube is filled with hot water.”
Like most thermal features, geysers are fragile rarities of nature. The Yellowstone National Park – which you need three full days to see its top sights – preserves the largest hydrothermal area on the planet.
Molten rock, or magma, may be as close as 5 to 13 kilometers underground. The magma provides the first ingredient for thermal features: heat. Ample rain and snowfall supply the second ingredient: water. The water seeps down several thousand feet (more than a kilometer) below the surface where it is heated. Underground cracks and fissures form the third ingredient: plumbing. Hot water rises through the plumbing to produce geysers and hot springs.
In geysers, constrictions in the plumbing prevent the water from circulating freely to the surface where the heat would escape. The deepest water can exceed the surface boiling point of 93 degrees Centigrade. The surrounding pressure also increases with depth.
Increased pressure exerted by the enormous weight of the overlying water and rock prevents the water from vaporizing. Small bubbles of steam form as a result. As they rise, they expand until they are too large and numerous to pass freely through the tight spots.
At a critical point, the confined bubbles actually lift the water above, causing the geyser to overflow. This decreases pressure on the system, and violent boiling ensues. A tremendous volume of steam is instantly produced and forces water out of the vent in a super-heated mass, and the eruption starts.
In an eruption, water is expelled faster than it can enter the geyser’s plumbing system. The heat and pressure gradually decrease. The eruption stops when the water reservoir is exhausted or when the gas bubbles diminish enough to be able to rise without ejecting the water.
The Yellowstone National Park is best known for its Old Faithful geyser, which shoots water every few hours. About 3,700 to 8,400 gallons of water are reportedly expelled per eruption, depending on the length of eruption.
It is thought by many scientists that geysers are predictors of earthquakes. For instance, only sixty hours before the October 1989, 7.1 – magnitude quake in the San Francisco Bay Area, Old Faithful’s usually dependable period suddenly lengthened to more than 100 minutes.
Scientists believe that small earth movements preceding the quake could have altered the size of the reservoir beneath the geyser, affecting its pressure and water flow rate. Could geysers save the lives of people by predicting earthquakes?
Geysers also affect us in our use of power. Steam from geysers is purified, transported in pipes, pressurized, and turned into electrical power. This electrical power is produced in various geothermal power plants in some parts of the world, including the Philippines. Geyser fields are ideal for this type of energy.
Unfortunately, geothermal energy production by humans steals the geyser’s water, and further destroys the geyser activity.
There are only about a total of seven hundred geysers on earth. The majority of the world’s active geysers are located in the Yellowstone National Park. Only three other locations – Iceland, New Zealand, and Kamchatka (in Siberia) – have large concentrations of thermal features.
In the Yellowstone National Park, five geysers – Old Faithful, Castle, Grand, Daisy, and Riverside – are predicted by the interpretive staff. Old Faithful’s average interval between eruptions is about 88 minutes, varying from 45-120 minutes. An eruption lasts 1-1/2 to five minutes and reaches a height of 106 to 184 feet.
When we arrived at the scene, thousands of people – who were waiting for several minutes already – were getting ready with their cameras to shoot the famous eruption.
Old Faithful is located in the Upper Geyser Basin, where most of the geysers in the world are concentrated. Another favorite performer is the Beehive geyser, which erupts twice daily and its display lasts 4-5 minutes.
The Lion Group consists of four geysers: Little Cub, Lioness, Big Cub, and Lion. Lion has the largest cone and erupts up to 50 feet for 1-7 minutes. If you witness its eruption, you might hear how this geyser got its name: the eruption is often preceded by sudden gushes of steam and a deep roaring sound.
I loved Doublet Pool for its series of ledges, elaborate border ornamentation, and deep blue waters. Doublet produces vibrations, surface wave motion, and audible thumps – most likely caused by collapsing gas and steam bubbles.
I want to thank my sister, Elena, and her husband, Engineer Daniel Chase, for bringing me to Yellowstone National Park. The trip was worth it, although it took us five hours from Livingston, Montana, to get there. –
