Geysers What They Are And How They Work Author:T. Scott Bryan With clear, succinct prose, Scott Bryan explains the geological setting that produces the pressure, heat, and abundant water necessary for a geyser to form and introduces us to the variables that shape each geyser s distinct personality. Some geysers spout just inches above a pool of water and others blast hundreds of feet in the air from conica... more »l vents. Some remain quiet for decades only to explode unexpectedly several times in a single month while others erupt regularly in scheduled intervals, year in and year out. While Bryan focuses on Yellowstone National Park, he also draws examples from geyser fields in Iceland, Chile, Russia, New Zealand, Africa, and elsewhere. First published in 1990 with black-and-white photographs, Geysers: What They Are and How They Work is completely updated, including many more photographs, all in color. An appendix with a detailed map describes the status of more than sixty geyser fields around the world. The book includes old photos of many now-extinct geysers and explains the natural and man-made causes of their demiseFor ages 12 and up« less