Figure 8.30: Devil’s Tower in Wyoming is a huge rock formation that was once magma that
cooled within a volcano. It rises to nearly 400 meters from its base. ( 29 )
Hot Springs and Geysers
Beneath the surface of the Earth, water works its way through porous rocks or soil. Most
caves, for example, are results of water’s erosion of the ground. At times, that water crosses
pathswithvolcanicactivity. Thesameheatthatmeltsrockintolavaheatsthewaterbeneath
the surface. If the water makes its way to the surface, it may emerge as either a hot spring
or a geyser.
Hot Springs
When that water comes to the surface under regular pressure, it creates a hot spring
(Figure8.31). A hot spring is a crack in the Earth through which water reaches the surface,
after being heated below the ground. Many people disagree on the exact definition of a hot
spring. However, everyone agrees that the water’s temperature is higher than normal. The
water in hot springs can even reach temperatures in the hundreds of degrees Celsius beneath
the surface. Most hot springs do not reach those great temperatures. In fact, many hot
springs are used by people as natural hot tubs. Many people believe that hot springs hold
curative properties. Hot springs are found all over the world, even in Antarctica!
Geysers
Like hot springs, geysers are created by water that is heated beneath the Earth’s surface.
When water is both superheated by magma and flows through a narrow passageway un-