Sizzling Sites We’ll head to a hot spring. Don’t dive into this pool. Its water is too hot to touch. It doesn’t start out that way. T e water in a hot spring starts


as cool rain or melted snow. It runs into cracks in the ground. It slowly drips down, down, down. Eventually, the water gets close to the magma chamber. T is trip can take hundreds, or even thousands, of years. Down there, Earth’s heat makes the


water boiling hot. T is hot water rises back to the surface. On the surface, it forms a pool, or hot spring. T is cycle repeats itself. Rain that


falls today will bubble up again in thousands of years!


Gushing Geysers A geyser is a hot spring, too. Like a pool, it starts with a slow drip. Yet its water doesn’t always move so slowly. Sometimes, it bursts from the ground. It looks like a fountain. Here’s why. Narrow cracks near the


surface trap water. T e water can’t escape Earth’s heat. It grows hotter. Suddenly, the water gets so hot,


some turns into steam. T e steam pushes the water sky high. T e geyser gushes until all the water is gone.


20 NATIONAL GEOGRAPHIC EXPLORER


Right on Time T e geyser isn’t done. Soon, more hot water rises from deep under the ground. It gets trapped. T e cycle starts again. It follows a pattern. T is is how we can predict when many geysers will erupt. Each geyser has its own schedule.


Plume Geyser shoots a spray of water about every 30 minutes. Riverside Geyser erupts every 6 or 7 hours. T e largest geyser here, Steamboat Geyser, may not erupt for years.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24