Clyde Wahrhaftig

Clyde A. Wahrhaftig (December 1, 1919 – April 6, 1994) was an American geophysicist. His research included the geology of the Sierra Nevada, the California Coast Ranges, and the glaciers of Alaska. He is also noted for his many field guides to geology of San Francisco and the Bay Area.

Wahrhaftig was born and raised in Fresno, California. He earned a bachelor's degree in geology at Caltech in 1941, and a Ph.D. in geology at Harvard in 1953. He worked for the US Geological Survey (USGS) from 1941 until his death in addition to teaching at University of California, Berkeley from 1960 to 1982. Having spent most of his career closeted, Wahrhaftig came out as a gay man upon his acceptance of the Geological Society of America's "Distinguished Career Award" in 1989. He had a close relationship with fellow geophysicist Allan Cox that lasted until Cox's death in 1987. He died of heart failure in San Francisco at the age of 74.

Wahrhaftig was a dedicated user of public transportation. He eschewed automobiles and airplanes and routinely traveled by sea to his field work in Alaska. He continued to use horse-pack trains while working in the field for as long as the USGS permitted it. His support of public transportation also helped him fulfill his commitment to making geology accessible to the public by writing field guides that could be understood by laymen and did not require long trips by car to see the relevant sites. Some of his most popular field guides include Streetcar to Subduction and Other Plate Tectonic Trips by Public Transport in San Francisco, A Walker's Guide to the Geology of San Francisco, and The Hayward Fault in Hayward and Fremont, via BART.

Wahrhaftig has made significant scientific contributions to the field of geology. He was one of the first Bay Area scientists to bring the role of plate tectonics in causing earthquakes to public awareness. He was also one of the pioneers in applying geological science to environmental problems, with a particular focus on forest management practices. He was appointed to the California Board of Forestry in 1975, where he advocated for forest practices legislation that took a long-term perspective on geomorphological effects of forest management. His work is credited with inspiring the research of many others who went on to serious geological study, including the universal applicability, or lack thereof, of dynamic equilibrium and interest in topographic development of Alaska and the California Coast Ranges.

In 1967, Wahrhaftig was awarded the Kirk Bryan Award by the Quaternary Geology and Geomorphology Division of the Geological Society of America, and the GSA's Distinguished Career Award in 1989.