2008 Q & A
June 20, 2008
Tell me more about the geysers. Where does the water comes from and what makes the geyser blow? Geoff and Cady, 3rd grade, Holly Ridge Elementary, Wake County and the 1st grade, Wiley Elementary, Wake County
Yellowstone is one of the most geologically dynamic areas on Earth due to shallow source of magma. The source of water in the thermal features is groundwater, rain and snow melt that seeps underground over time. Snow and rain slowly percolate through layers of porous rock riddled with cracks and fissures. Due to the shallow magma chamber beneath Yellowstone, the water’s temperature rises well above the boiling point but the water remains in a liquid state due to the great pressure and weight of the overlying rock and water. The result is superheated water with temperatures exceeding 400°F. The superheated water is less dense than the colder, heavier water sinking around it. This creates convection currents that allow the lighter, more buoyant, superheated water to begin its journey back to the surface following the cracks, fissures and weak areas. As hot water travels through this rock, the high water temperatures dissolve some silica in the rhyolite. Some of this silica is deposited as a coating on the walls of the cracks and fissures, making a sealed “plumbing system”. The last thing needed for a geyser is a constriction in this plumbing system. A constriction allows great pressure to build up (like putting your finger over the end of a water hose). At a critical point, tremendous amounts of steam force water out of the vent, and an eruption begins.
Does global warming affect the park? What kind of weather and precipitation changes has Yellowstone experienced over the last few years? Erin, 10th grade, Southeast Raleigh Magnet High, Wake County; Dylan, Newport Middle School, Carteret County; and Abi, 5th grade, Union Elementary, Lincoln County
Rangers told us that this year was the first normal precipitation year in the park in a decade. From the park's literature we learned that global warming is and may in the future affect the park's ecosystem in a variety of ways: growing season has already increased by about two weeks; alpine habitat will decrease, affecting almost all alpine flora and fauna; Grizzly Bear alpine food sources (Whitebark Pine, Army Cutworm Moths) will decrease; Sagebrush-Steppe conditions, such as on the northern range, will increase; insect pest and exotic invasive plant problems may increase, etc. How all this will impact the wildlife and plants is yet to be determined, but park managers are already beginning to monitor and record changes. Meanwhile, the park is taking steps to reduce carbon emissions through recycling, using biodiesel and ethanol in vehicles, as well as other methods.
What is the potential for geothermal and other non-environmentally disruptive energy resources in the Yellowstone area? Morty, Beaufort Middle School, Carteret County
The park's thermal features lie in the only essentially undisturbed geyser basins left in the world. In Iceland and New Zealand, geothermal development has reduced geyser activity and hot spring discharge. The park's mission is to protect and preserve the unique natural resources for the future, so development of geothermal resources within the park is unlikely. Development outside the park may occur but no one knows what impact this might have on the geothermal activity within the park as the full story of how it is all interconnected is unknown.
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