"Readers learn about the past, present, and future of geothermal power through this . . . book. Topics covered include how geothermal heat is created and brought up to Earth's surface, the surface features, such as lava flows, hot springs, geysers, and fumaroles, that are signs of it, and how geothermal heat pumps and geothermal power plants work. The need for renewable energy sources such as geothermal energy is addressed, as is the need to manage geothermal resources sustainably"--Amazon.