Barry Voight (born 1937) is an American geologist, volcanologist, author, and engineer. He was a professor of geology at Pennsylvania State University from 1964 until his retirement in 2005. He still conducts research on rock mechanics, plate tectonics, disaster prevention, and geotechnical engineering. In April 1980, Voight's publications on landslides, avalanches and other mass movements convinced Rocky Crandell of the U.S. Geological Survey (USGS) to ask him to look at a growing bulge on the Mount St. Helens volcano in the state of Washington. Voight predicted the collapse of the mountain's north flank as well as a powerful eruption. After his predictions were realized in May 1980, he was hired by the USGS to investigate the debris avalanche that initiated the eruption. His work at St. Helens brought him international recognition, and he continued researching and guiding monitoring efforts at several active volcanoes, including Nevado del Ruiz in Colombia, Mount Merapi in Indonesia, and Soufrière Hills, a volcano on the Caribbean island of Montserrat.
