Randy Armstrong, age 12, of Galesburg, Illinois, for his question:
Why is water from a geyser hot?
The frothy fountain from a geyser is mostly gaseous steam. It reached the boiling point of water deep in the earth's crust. Down there, the geyser has a special plumbing system with a durable furnace to supply the heat energy for the spectacular operation. The true geysers of the world occur in only three major regions and their locations reveal how the earth creates them.
Most of the world's geysers are located in Iceland, New Zealand and in North America's Yellowstone National Park. These are regions of recent volcanic activity associated with the formation of new crustal layers. Under normal conditions, pressure and heat increase with depth and crustal layers three miles below the surface are hot enough to boil water. Under volcanic conditions, friction from crustal unrest creates enough heat to melt buried minerals into pools of molten magma.
This enormous heat energy is capped below massive layers of cool solid rocks ¬until cracks occur in the solid surface. Then the pressure is released and the buried superheated magma erupts. It spews fumes and various gases into the air and boiling minerals in flows of lava. Sometimes rivers of lava reach the surface where they soon cool in the air and form solid lava rocks. Sometimes the magma fails to reach the surface. It may intrude through underground crustal layers, or get buried below landslides.
When this hot volcanic material is buried, it tends to retain its heat energy for centuries. However, this gradually escapes to the surface, creating hot mineral springs and bubbling mud pots, smokey fumaroles and gushing geysers. These geological wonders that occur in fields of fairly recent volcanic activity are powered by deeply buried volcanic heat energy, carried up by rising gases.
A geyser requires an underground plumbing system with crooked pipes and perhaps a buried cauldron. These cavities fill with water. Some is seeping ground water and some may be created from oxygen and hydrogen gases by the trapped volcanic energy. The captured water is heated by pressure from above and by volcanic energy trapped in deep crustal layers.
Normally, boiling water rises in convection currents and converts to steam. A geyser's crooked plumbsng prevents normal convection ar keeps the superheated water under pressure until the surface boils over. This releases pressure on the superheated water below. In a flash, some of it converts into steam and the geyser erupts. Meantime the crooked plumbing system refills with water and the trapped volcanic heat energy prepares it for the next frothy eruption.
Fiery volcanoes also have beneficial features. Their porous lava rocks enrich the soil and plants use their erupted carbon dioxide to make oxygen. Fields of recent volcanic activity hold enormous supplies of geothermal energy. In the future, we may see fewer geysers and fumaroles because their energy can be used to generate non polluting electric power. We expect the reduction of pollution to require sacrifice but not Old Faithful! This super geyser is safely protected forever in Yellowstone National Park.