Lamont-Doherty Earth Observatory, Pallisades, New York
The 1996 Maurice Ewing Medal was presented to Walter C. Pitman, III, at the Fall Meeting Honor Ceremony December 17, 1996, in San Francisco. The medal recognizes significant contributions to understanding physical, geophysical, and geological processes in the ocean and outstanding service to the marine sciences.
“Walter Pitman received his bachelor of science degree in engineering from Lehigh University in 1956. He turned to industry and worked for Hazeltine Corporation from 1956 to 1960; becoming bored with the corporate lifestyle, he decided that he wanted a change. Trained as an engineer and having had no experience in either geophysics or geology, Walter nevertheless decided that he wanted to study oceanography, having become interested in the subject through his experience in industry. He visited Lamont Observatory, where he was told he might be able to have a future in marine science but first he would have to go to sea for a year as a technician. Then, perhaps, he could be sponsored as a student to Columbia University. This he did in 1960, becoming a seagoing electronic technician in charge of keeping the magnetometer and other instruments operational. During 1960, Walter spent considerable time in the South Atlantic and in the eastern Pacific. He had many adventures, some of them believable. He then returned to Lamont Doherty Geological Observatory in 1961 and officially became a graduate student in geophysics. “I first met Walter in 1963, after my return to the United States from Africa. At the time, Walter was pursuing his Ph.D. thesis on micropulsation under the direction of Jim Heintzler. In 1964, he changed his thesis and decided to study marine magnetic anomalies. He went to sea in 1965 as chief scientist on the Eltanin 20 leg, returning to Lamont Doherty with an excellent set of data. As luck would have it, he processed both the Eltanin 19 and 20 data and produced the Eltanin 19 profile that would revolutionize the Earth sciences, probably the most famous single magnetic profile in the history of the subject. This data set clearly supported the Vine, Mathews, Morley hypothesis and persuaded many that seafloor spreading was a reality. This study was published by Pitman and Heirtzler in 1966 and was the basis of the first magnetic polarity timescale based on marine magnetic anomalies.
“Lamont Doherty Geological Observatory had the best library of marine magnetic anomaly data for the world ocean, and Walter and others rapidly expanded the investigation and correlation of magnetic anomalies back in time to the quiet zone and geographically into all the oceans of the world, laying the basis for the epocal Heirstler et. al. paper in 1968 that is one of the most highly cited papers in all of geophysics. These papers were followed by a study of the kinematics of the North Atlantic based on magnetic anomalies, published in 1971 and 1972 by Pitman and Talwani. Walter, along with R. Larson, succeeded in extending the reversed sequence into the Jurassic in 1972. A direct result of his study of the kinematics of the Atlantic Ocean was the study with J. Dewey and others of the evolution of the Alpine system, a topic with which he has remained engaged. In this period, Walter led the effort to produce a complete map of magnetic anomalies in the world ocean, which was published in 1974 by Pitman, Larson, and Herron as a world map giving the ages of the ocean basins. This study enabled workers to reconstruct in detail the paleogeography of Earth since the middle Jurassic. With L Hays, in 1973, Walter also pointed out the paleogeographic consequences of rapid seafloor spreading in the Cretaceous caused a large rise in sea level and the consequent flooding of the continents. This 1973 paper led to a gradual shift in Walter’s emphasis to problems concerning plate tectonics and sea level change. In 1978, Walter produced his classic paper linking eustasy and stratigraphic sequences on passive margins and relating to plate tectonics. This paper remains one of the most important contributions to the subject in the literature, and Walter’s interest in sea level change remains. Walter’s most recent important contribution was the study with Golovchenko of the effect of sea level change on the morphology of mountain systems, published in 1991. Walter is at present nominally retired; however, he is in the process of publishing a book with W. Ryan entitled, Noah’s Journey. This magnum opus has been under gestation for at least 20 years and will surely be one of Walter’s most important contributions. For these outstanding contributions to marine science, Walter Pitman clearly deserves the Ewing medal.”
—NEIL D. OPDYKE, University of Florida, Gainesville
“I am very honored and deeply grateful to be this years’ recipient of the Ewing Medal. I owe much to many people throughout my career, particularly to Jack Nafe and Chuck Drake, who sponsored me as a graduate student and who occasionally propped me up when I faltered, to Jim Heirtzler, who was so patient and who nurtured me through the graduate years, to Ellen Herron, Geof Dickson, and Xavier LePichon, coauthors and collaborators on those early papers; and to Neil Opdyke, who pushed us all. I owe much to the many wonderful colleagues with whom I have been able to work, such as John Dewey, Bill Ryan, Manik Talwani, Dennis Hayes, Jeff Fox, Jim Hays, Roger Larson, John La Brecque, Steve Cande, and many others.
“I owe much to serendipity, having been in the right place at the right time. Lamont-Doherty was the right place to be at the time, with its large collection of data, organized, archived, and open to all. The data were processed on a regular and routine basis and harnessed to our computer system, which then consisted of several 1620s. The data were from all oceans, due to the insistence of Maurice Ewing that all oceans be explored and that all the data that could be gathered were gathered at all times.
“The magnetic lineation patterns were but a part of what seemed to be a continuous chain of discovery by many people, of the piecing together of geologic events in new causal linkages, at first called `the new global tectonics’ and later `plate tectonics.’” In a sense, the plate tectonics organized much of the geology, like looking at a pointillist painting; up close it is just a field of spots, but from a distance the organization appears. Dots and patches which had seemed only distantly related at best now appeared as an integral part of an overall pattern. But if the paradigm solved problems at one level, it created problems at another. Did the ridges push? Did the trenches pull? Both or neither? Deep or shallow mantle convection? Or both? All of the above or none of the above? In addition, as NASA sent vehicles to outer space, the question was always asked as to whether this or that planet or moon exhibited any behavior that could be likened to plate tectonics.
“One thing that became clear immediately from the pattern of magnetic stripes in the oceans, is that the tectonic history of the oceans is much simpler than that on land. There has also been an important difference in how the exploration of each of these geographic entities was carried out. The land surface had been explored for hundreds of years at its very surface, with occasional probes to depth. It was only after mapping each of the many trees that the forest could be seen. At that, synthesis at the continental or intercontinental scale was fraught with difficulty, and the conclusions were always controversial. In the oceans, the entire process of exploration was different. The first and most of the explorations have been accomplished from the deck of a ship, usually some kilometers over an invisible ocean bottom, and later with airborne instruments and now even from satellites. This is particularly true with the magnetic data, which so dramatically illustrated the geometric regularity of the ocean basins, taken from ships 3 to 6 km above the ocean bedrock and the aeromag even a few kilometers higher. Where would we be if the oceans had been dry, and we were forced to explore amongst the canyons, rifts and hills of the bedrock surface, making our measurements of these intensely magnetized rocks, little suspecting the orderly pattern that lay hidden amongst the apparent chaos?
“I feel very fortunate that I wandered into Lamont and into this way of life, free to more or less rummage around, trying to find out how things work just for the sake of finding out, and having the privilege and pleasure of watching others do the same. In addition, I was actually paid a salary! There are probably very few universities like Columbia in which an institution like Lamont-Doherty would have been allowed to grow and flourish in such a benign fashion, so unencumbered, but none of this would have happened if it had not been for Maurice Ewing, who founded the Observatory and whose dedication, energy, and vision made it what it is today.”
—WALTER C. PITMAN, III, Lamont-Doherty Earth Observatory, Pallisades, New York