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Geysers by Phoebe and Shannon

We love exploring Yellowstone National Park. There are so many cool things to see: the canyon, waterfalls, wildlife, lakes, hot springs, and geysers! We went to Canyon Visitor Center to learn more about these features-especially the thermal basins, places where there are lots of geysers or hot springs. We were curious: Why doesn't every thermal basin have a geyser?

What did we do?
At the Canyon Visitors Center, we saw an exhibit that explained Yellowstone's unique geology. The park sits on a really big hot spot, made up of magma that rises from deep in the earth. All this magma heats up the ground water in the area and creates thermal features including geysers, hot springs, fumaroles, and mud pots. Geysers are thermal features that have narrow space in their plumbing. Steam forces water through this opening and boom, the geyser erupts! We looked at other exhibits that explained why we only saw geysers in some areas of the park-it has to do with rock. With all the different kinds of rock in the park, we thought it was time for good old fashioned DFTV field work! We headed to Mammoth Hot Springs, which doesn't have geysers, and Upper Geyser Basin, which is home to a lot of geysers. We decided to take water temperatures and check out the kinds of rock found in each area.

What did we find out?
Temperatures at hot spots in the Mammoth Hot Springs area were between 80° and 130° Fahrenheit. The rock in the area is really porous. Near the Upper Geyser Basin the water features are much hotter, between 137° and 183° Fahrenheit. Rocks were not as porous here. You could say they were, well, hard as a rock! Using our infrared thermometer, we even took the temperature of a geyser when it was shooting. It was between 99° and 114° Fahrenheit. We calculated the average water temp in two locations-96° in Mammoth Hot Springs and 171° in Upper Geyser Basin. Because the rock is porous in Hot Springs area, it bursts when under pressure, rather than forming a geyser. Rock makes all the difference!

What can you do?
  • Creat some mineral features like those in Yellowstone. Wearing goggles and gloves, and working where there is good ventilation, carefully mix one-quarter cup household ammonia, one-quarter cup salt, one-quarter cup water, and a spoonful of laundry bluing liquid. Stir, then pour over some charcoal briquettes, or chunks of sponge, set in an aluminum pie plate. Put the pie plate where it won't be disturbed for several days. After five days, look at how a mineral formation has formed on the charcoal.
  • Make a mini-geyser. Find a plastic film canister with lid. Carefully poke a hole in the center of the lid with a nail. Fill the canister about three-quarters full with warm water. Break up a seltzer tablet into chunks, and put a few chunks into the water, then quickly put on the lid. Cover the hole with your thumb, shake, then release your thumb. You should see a small eruption of water emerge from the canister lid.
more resources
Go to the DFTV Boards, and tell us about your science investigation.
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