ASU Research E-Magazine: Frozen Legacy

Geologists enjoy research with a solid foundation. But Troy Péwé’s scientific career was always anchored in ice—frozen ground in its many forms, to be precise.

An ASU professor emeritus of geology, Péwé passed away on October 21, 1999. He was one of the world’s leading experts on permafrost. The University of Alaska recognized Péwé’s years of work in September 1999. The Troy L. Péwé Climatic Change Permafrost Reserve is the frozen legacy of his scientific effort and contributions.

Located near Fairbanks at a site called Gold Hill, the reserve includes 25 acres of permafrost, perennially frozen soil that holds a geologic record dating back 3 million years locked in its icy grip.

Mining companies removed more than $4.4 million worth of gold from gravel at the site in the mid 1950s. Their operations chewed through the frozen layers of windblown “loess” dust and the ash layers deposited by prehistoric volcanic eruptions. The miners created 200-foot high silt cliffs.

The ASU scientist studied the permafrost in the area named for him for more than 50 years. Splayed open with boreholes, layers of ground revealed in the silt cliffs show evidence of past global warming trends and times of cooler climates. The ground also preserved ancient tree trunks and the remains of long-extinct creatures such as woolly mammoths, giant beavers, and saber-toothed cats.

Twenty percent of the planet’s land surface is perennially frozen, including 82 percent of Alaska. In addition to preserving the remains of various forms of prehistoric life, permafrost poses intriguing questions for geologists and immense problems for engineers.

“The ground at this site reads like a geologic calendar,” Péwé said during an interview just a few months before his death. “After 50 years of work, it is nice to have my name on this ground. The object is to preserve this area and its geologic record for years to come. In the future, scientists will study this ground using techniques and technology not even known today.”—Conrad J. Storad