Walter Heinrich Munk was born October 19, 1917 in Vienna, Austria. At age 14 his family sent him to a preparatory school in New York, envisioning a future for him in banking. Munk, however, had other plans. He enrolled at the California Institute of Technology and earned a bachelor’s degree in physics in 1939 and a master’s in geophysics in 1940. He attended Scripps Institution of Oceanography, and received his Ph.D. in oceanography from the University of California in 1947. Munk has spent his entire professional career at the Scripps Institution, and, in addition to his scientific work, has remained deeply engaged both in educating his students and in the university’s governance. He is presently (2004) professor of geophysics emeritus at Scripps.
During World War II, Munk and Harald U. Sverdrup, then director of Scripps, developed a system for forecasting breakers and surf on beaches, a technique of crucial importance in military amphibious landings. It was widely applied in the Pacific and Atlantic theaters of war, and it correctly predicted high but manageable waves for the Normandy invasion. During the 1946 testing of nuclear weapons at Bikini Atoll in the southern Pacific Ocean, Munk participated in an analysis of currents and diffusion in the lagoon and the water exchange with the open seas. He pioneered research on the relationship between winds and ocean circulation, coining the now widely used term “wind-driven gyres.”
In the 1950s, Munk focused on the wobble of the Earth’s axis during rotation. He observed irregularities in the Earth’s motion caused by geophysical processes, such as the momentum exchange between ocean currents and the solid Earth and the exchange of mass between polar ice sheets and oceans. In 1963, he led a study that showed that waves generated by winter storms in the Southern Hemisphere traveled thousands of miles and spread throughout the world’s oceans. To trace the path and the decay of wave packets as they propagated northward, he established stations in a great circle from New Zealand to Alaska and measured fluctuations with pressure-sensing devices lowered to the ocean floor.
Beginning in 1975, Munk and Carl Wunsch of the Massachusetts Institute of Technology pioneered the development of acoustic tomography of the ocean. The technique uses sound waves to generate images of water in much the same way that radioactive particles are used to create images of the brain in CAT scans. Munk developed the theory that by studying the sound propagation patterns and the time it takes for sound to travel through the oceans, it would be possible to detect important information about the ocean’s large-scale structure. He thus conceived the Heard Island Experiment, in which acoustic signals were transmitted by instruments lowered 150 meters underwater near the remote island in the southern Indian Ocean. During four days in January 1991, in an experiment that has been called “the sound heard around the world,” signals sent from Heard Island were received on the east and west coasts of the United States, as well as at many other stations around the world.
Walter Munk was elected to the National Academy of Sciences in 1956 and to the Royal Society of London in 1976. He has been a both a Guggenheim Fellow (three times) and a Fulbright Fellow. He was also named California Scientist of the Year by the California Museum of Science and Industry in 1969. Among the many other awards and honors Munk has received are the Arthur L. Day Medal from the Geological Society of America in 1956, the Sverdrup Gold Medal of the American Meteorological Society in 1966, the Alumni Distinguished Service Award from the California Institute of Technology in 1966, the Gold Medal of the Royal Astronomical Society of London in 1968, the first Maurice Ewing Medal sponsored by the American Geophysical Union and the U.S. Navy in 1976, the Alexander Agassiz Gold Medal of the National Academy of Sciences in 1977, the Captain Robert Dexter Conrad Award from the U.S. Navy in 1978, the National Medal of Science in 1985, and the William Bowie Medal of the American Geophysical Union in 1989.
Overall, Walter Munk is a member or fellow of more than a dozen professional societies and has served on many university, national, and international committees as well. He has also, over the course of his long career, written more than 200 scientific papers.