Yellowstone Surprises
Everyone has heard of Yellowstone and its regularly erupting geyser, Old Faithful. So, of course, this National Park had to be on our list of things to see as we travel the US this summer. However, I had not anticipated at all what we encountered. I knew part of the area Yellowstone covers was once a super-volcano, A huge eruption about 631,000 years ago made the center collapse, and a 30 by 45 mile caldera or basin was formed. Magma lies below as close as 3-8 miles (5-13 km) from the surface. The heat of the magma fuels the park's geysers, hot springs, fumaroles, travertine terraces, and mudpots. In fact Yellowstone boasts the world's largest group of such hydrothermal features, and incidentally there are hundreds of small earthquakes below ground annually which means these features are in a constant state of flux. I'm not intending to give you a geography lesson, you can visit the park's website to learn more about it, but I will describe to you what I