Duffield, Wendell

geology from Stanford University in 1967.

During the following four decades, he

studied volcanoes around the world as

an employee of the U.S. Geological

Survey. Now retired, Duff leads field

trips, consults about geothermal energy,

and writes books and articles for the

general audience. Duff and his wife,

Anne, spend summers in the lake country

of northwestern Wisconsin and winters in

Flagstaff, Arizona.