Only a few years ago geologists thought that the water ejected by hot springs was primary water released from molten magmas far below the surface. Now new lines of evidence, including measurements of oxygen and hydrogen isotopes, shows that nearly all of the water is recirculated groundwater.
The accompanying diagram shows this concept and how a geothermal well might be obtained.
Located north of Fairbanks in the Yukon-Tanana Uplands are a number of hot spring localities. These extend from the Salcha River watershed westward to the Seward Peninsula. The better known hot springs in this region are Chena Hot Springs, Circle Hot Springs and Manley Hot Springs, all accessible by road.
Diagram by R. B. Forbes and N. Gibbar, Northern Engineer, 5 Spring, 1973
