(1911-1974) American Geophysicist, Rock Mechanics
David Griggs had a true dual career, one in geophysics and one in national defense. He is truly the “father of modern rock mechanics.” He greatly modified existing high-pressure experimental equipment that had been neglected for many years, or invented new equipment. One such apparatus, the “simple squeezer,” achieved pressures up to 50 kilobars and temperatures up to the melting point. This equipment was unique in the world at the time. He then conducted exhaustive experiments on natural rock samples to determine their mechanical properties. He performed “creep” experiments in which he placed materials under high pressure and temperature conditions for periods up to nine months, allowing them to deform slowly. These conditions simulated the deep crust and mantle. The results and the processes that he defined are still the state of the art for the science. This research placed the first real constraints on deformational microtextures observed in naturally deformed rocks and the processes of developing alignment of minerals in metamorphic rocks. He defined the material science of many rocks and minerals in terms of strength and response, whether fracturing in a brittle response or stretching in a plastic response. In 1965, Griggs discovered a phenomenon he called “hydrolytic weakening” in minerals. The addition of very small amounts of water actually bonded into the quartz atomic structure caused significant weakening. The mechanism is not fully understood but it may be one of the most significant controls on deformation in the shallow to mid-crustal range.
This interest in rock deformation stemmed from Griggs’s interest in mountain building processes. He wanted to better understand the deformational processes responsible. Before he started his groundbreaking experimental studies, he wrote a paper entitled “A Theory of Mountain Building” in which he proposed that thermal convection currents in the mantle were largely responsible for the distribution, structure, and periodicity of mountain building events. Even though the ideas were later proven sound during the plate tectonic revolution of the 1960s, at the time of publication they were roundly denounced and dismissed. It was Griggs’s drive to vindicate his ideas that led him to undertake his later advanced experimental work.
David Griggs was born on October 6, 1911, in Columbus, Ohio. He spent his early childhood in Ohio, but his high school days in Washington, D.C. His father was a professor of botany at George Washington University and took expeditions to Puerto Rico, Guatemala, Texas, and Alaska where he discovered the famous Valley of Ten Thousand Smokes, near Mount Katmai. The highest mountain in the area was named Mount Griggs in his honor. David Griggs began his college career at George Washington University in 1928 but quickly transferred to Ohio State University and graduated with a bachelor of science degree in geology, Phi Beta Kappa, in 1932. He spent one year as a graduate student at Ohio State University before transferring to Harvard University, Massachusetts, and became a junior fellow the following year. During World War II, he served at the Massachusetts Institute of Technology Radiation Laboratory to develop microwave radar, and as an expert consultant to Secretary of War Henry Stimson. However, to introduce radar-guided bombing, he flew both training and combat missions in Europe, but after almost falling out the bomb bay doors on one mission and getting wounded on another (he received the Purple Heart), he was grounded. He then served with the Tactical Air Command. After VE day, he moved to the Pacific theater, where he was the liaison between General Douglas MacArthur and his staff, as well as prepared for the atomic bombing of Hiroshima. He received the Medal for Merit, the highest civilian honor, from President Truman for his efforts. Griggs married Helen Avery on May 4, 1946. They would have two children.
Griggs continued his activity in national defense even after the war. He worked with the Atomic Energy Commission and helped set up the RAND Corporation, serving as its first head of physics in 1947. He accepted a faculty position at the University of California at Los Angeles in 1948, but also served as chief scientist for the U.S. Air Force from 1951-1952. He became infamous in this role for supporting the government’s desire to build a hydrogen bomb, in direct opposition to the position of J. Robert Oppenheimer, the head of the Manhattan Project, who was opposed to it. Many scientists regarded him as a Judas for this stand. Griggs got involved in an active combat situation when in 1967 he went to Vietnam to help General William Westmoreland design a scientific support structure. He improved the performance of new sensor technology to cut off enemy supply lines during the Tet Offensive.
David Griggs died of a heart attack during vigorous skiing in Colorado with former Secretary of Defense Robert McNamara. He had had a precedent heart attack but in typical Griggs style, he ignored it.
