VII. Watching Waves in Land and Sea:
The Institute of Geophysics
and Planetary Physics
The redwood laboratory that houses the Institute of Geophysics and Planetary Physics on the Scripps campus — and the variety of projects there carried on by researchers — are the result of the persistence of one enthusiastic man, Walter H. Munk. He was described by Chancellor Herbert F. York in 1963 as having been “unceasing in his drive and efforts to bring about the realization of his dream.”[1]
As noted in chapter 2, Munk had been a prewar and postwar student of Harald U. Sverdrup. After receiving his Ph.D. in 1947, Munk became an assistant professor at Scripps. When he became professor of geophysics in 1954, Munk also became associated with the intercampus Institute of Geophysics.
That institute, which had been established in 1946, was headquartered at UCLA. From 1947 to 1961 it was directed “with vision and energy” by Louis B. Slichter, who always had a keen interest in Scripps projects, and in fact had provided support for the Scripps Institution's first major expedition, Midpac, in 1950. Upon Slichter's retirement, Nobel Laureate Willard F. Libby became state-wide director. The institute has carried out a vigorous
On the Scripps campus during the latter 1950s, the institute's sole representative, Walter Munk, was anticipating an expansion in geophysics. He was also considering an offer from Harvard. Roger Revelle asked, “What is it that you really want to do? Why is it that you could not do this better here than at Harvard?” So Munk consulted with Slichter, with Revelle and others, and in June 1959 he presented a proposal for the university's consideration:
The tremendous publicity of the [International Geophysical Year] and the increasing activity in rocketry as a means of investigating physical conditions between the planets for eventual space travel have made geophysics and planetary physics fashionable sciences. … Because of the small number of outstanding workers, the competition for good talent will be fierce until more investigators and teachers are produced. In this difficult transitional period it is essential that the University of California maintain its favorable position in geophysics by keeping and attracting first rate men and by providing them with facilities and especially with the environment in which they would be most productive.
Our university's position is favorable because it already has a nucleus of capable geophysicists and an
― 151 ―administrational framework which has served them effectively. But we need to provide room for new blood. … We propose that as part of the expansion of geophysics at the University of California a branch of the Institute of Geophysics on the UCLJ [= UCSD[*][*] For a short time UCSD was known as the University of California at La Jolla.
] campus be established.The Institute of Geophysics at UCLA (IGUCLA) has demonstrated how an intimate group of first-rate scientists can raise the standard of an entire campus community and be successful in attracting leading young people. The principal cause of its success is of course the quality of its senior members. However, the effectiveness of most of them is increased several fold by daily association with one another, which is difficult to bring about in too large and too diverse a group. To accommodate the diversity of interests in geophysics we propose to take advantage of the state-wide aspect of the Institute of Geophysics. By creating a branch of the Institute on the La Jolla campus, the Institute of Geophysics can grow without suffering from elephantiasis.
. . . The establishment [of a branch on the La Jolla campus] will benefit the expanded campus at La Jolla in the same way as it has benefited UCLA, by providing opportunities for graduate and postdoctoral research for outstanding young people.
. . . Emphasis is to be placed on appointments of young men. Large project-type research activities are to be avoided. The field of research is, of course, the concern of each senior investigator. Initially the appointments might reflect the activities of the senior investigators available for the formation of its nucleus.
― 152 ―We suggest that it be planetary physics with initial emphasis on the Earth-Moon system.. . . We thus envision an institute located near the Scripps Institution … which by 1964 might consist of a dozen senior investigators and be about 10 per cent the size of Scripps. The combined Los Angeles and La Jolla branches of the state-wide institute would possess a faculty in Earth (and planetary) science second to none in the country.[3]
Munk's proposal, favorably received by university officials, led to the establishment of the La Jolla branch of the Institute of Geophysics in 1960. As a modest beginning, Slichter provided $2,500 for a student fellowship and $1,000 for “unrestricted use in meeting minor needs” at the new facility in its first year. Munk was appointed director of the La Jolla branch and associate director of the statewide institute, which, also in 1960, added “and Planetary Physics” to its original name. Since then the Institute of Geophysics and Planetary Physics has been referred to usually as IGPP.
Munk stated his objectives:
We plan to study the planet Earth, its atmosphere, oceans and interior, using the methods of experimental and mathematical physics. … We propose to form a group that is at the same time small and non-specialized, and it is this unusual combination that will make our institute distinctive. … By our insistence to remain small we shall form a closely knit (though heterogeneous) group, requiring a minimum of administration and permitting all of us, including myself, to devote our time to teaching and research. … Dr. Revelle has suggested twelve senior investigators as the ideal ultimate size.[4]
Within its first year the new branch of IGPP had results to show. George E. Backus joined the staff and began mathematical approaches to the problem of rotational line splitting. Richard A. Haubrich arrived, and set up a precise seismic station on Miramar Ranch, once the home of E. W. Scripps. Munk and Gordon MacDonald (of the UCLA branch) undertook a study of atmospheric tides. The direction of arrival of ocean waves was also under study, and from the records Munk was able to identify long swell that had been generated halfway around the world in the Indian Ocean. Records from earthquake-generated sea waves, tsunamis, were scrutinized; the resonant oscillations along the California coast were recorded. Visitors came, some for a few days and some for many weeks. The first of these was the already frequent visitor to Scripps, Sir Edward Bullard, who began developing a generalized program for the analysis of geophysical time series. That computer program was named BOMM for its several devisers: Bullard, Florence Oglebay, Munk, and Gaylord Miller.
The earliest members of the IGPP staff at La Jolla did not easily have “daily association with one another,” as they were scattered throughout the Scripps Institution buildings. In 1960 the institution was serving as the staging area for the School of Science and Engineering and for the incipient UCSD, and everyone had office space problems. At the end of the first year of the new organization, Munk's complaint was that “we have no home.” He set out to find one.
Estimates indicated that a fully equipped laboratory of appropriate size would cost about one million dollars. Because the institute appointments were to be joint ones with teaching departments, the regents of the university agreed to match funds acquired from outside sources. Munk's efforts brought in contributions of $200,000 from the National Science Foundation, $20,000 from the
Meanwhile, a scenic site was found for the new building overlooking the sea, near the wooden cottages on the upper slopes of the Scripps campus. University architects commented that a building on that site could someday slide into the sea (an admittedly awkward disaster for geophysicists, who should know better), and advised against redwood, as such material would last only a century. Munk and his wife Judith, an architectural designer and sculptor, insisted on the site and the material — and won, chiefly on the leverage of the funds Munk had obtained from outside sources. Judith Munk advised on the building's design throughout the planning sessions. When the split-level building, stepping up the slope, was completed in 1963, the Munks were gratified that it had been built at the lowest cost per square foot of assignable space ($20.90) for a university laboratory in many years. The redwood building contains laboratories, offices, a machine shop, a library and reading room, and a conference or lecture room within its four levels.
The redwood laboratory of La Jolla's Institute of Geophysics and Planetary Physics, in 1969.
To enhance the grounds of the new building, philanthropists Cecil H. and Ida Green offered to buy a sculpture that Judith Munk had long admired: “Spring Stirring,” by San Diegan Donal Hord, under whom Judith Munk had studied sculpture. The massive work, carved from black diorite from Escondido, and mounted on a matching base, was installed in the patio of the building in the fall of 1963. It represents a huddled figure, partly shrouded and stirring from sleep; at its feet, as though pushing from the earth, are small sprouts. Cecil Green, equipment manufacturer and founder of Texas Instruments, noted that “this gift arises out of our very high regard for the unique ability and valuable contributions being made by Professor Munk to
Within its first few years the new laboratory reached the size advocated by Revelle and Munk, about twelve faculty appointments. As stipulated by the university regents for an institute, faculty appointments in IGPP are joint ones with a teaching department of the university. Because of the proximity and similarity of interests, many of the appointments at the La Jolla branch of IGPP are jointly with Scripps Institution. The remainder are with the upper-campus teaching departments of applied mechanics and engineering sciences (AMES) and physics. In addition, several Scripps researchers not officially part of IGPP, but whose studies are related, have offices in the IGPP building. Carl Eckart was one of these for several years prior to his death in 1973. A number of graduate students, working under the faculty members in their respective departments, have office and laboratory space there also.
To all intents and purposes, the La Jolla branch of IGPP operates as a laboratory within the Scripps Institution. The geophysical studies carried out in the redwood laboratory are selected by the senior scientists. Under the theme that “land geophysics and ocean geophysics are part of the same subject,” these studies have been aimed at both the restless ocean and the quivering earth. With ships and equipment, ashore and afloat, for fifteen years this group of geophysicists has been seeking answers to puzzles from the surface of the sea to the core of the earth.
Walter Munk's own studies have been chiefly concerned with the ocean in motion: its waves and its tides. As noted in chapter 2, during World War II he had devised the means of forecasting sea and swell for amphibious landings. After the war he continued with studies of ocean waves. Using records from wave meters installed outward from the pier, he worked out the relationships for computing the travel time and distance of a storm. He also developed equations for estimating the forces and motions exerted by waves on vertical beams. Munk's colleague, Frank E. Snodgrass, an ingenious engineer, designed sensitive pressure meters to track wave trains across the ocean. In 1963 a series of six tide stations was set up from Alaska to New Zealand, five of them on islands and the sixth on Flip, on station north-east of Hawaii. Munk and his family lived for three months in a native village in American Samoa, tending one of the stations. From the array of stations Munk could trace waves generated by storms in southern waters as they moved northward, to reach the northernmost station two weeks after their origin.
For studies of tides in the deep ocean, Snodgrass in the early 1960s designed an instrument capsule in the form of a pair of aluminum spheres that could be dropped free-fall to the sea floor, where it could be left for as long as several weeks and could be recalled by an acoustic command that causes the release of a link to the weighting storage batteries. On magnetic tape in the capsules could be recorded pressure fluctuations as small as the equivalent of one one-hundredth of an inch in sea level at a depth of three miles, temperatures to a resolution of a few millionths of a degree, and tidal currents as slow as ten feet per hour. The first tide capsule, launched in 1965, was christened Judith, at the suggestion of her husband; each succeeding one was christened by one of the project's participants for his wife. Despite many early problems with the capsules
In 1969 Snodgrass boarded the National Science Foundation research ship Eltanin to set out three tide capsules at depths of 12,000 to 18,000 feet in the Antarctic Ocean, an area in which the tidal configuration was unknown. Munk joined Snodgrass during the Antarctic summer to participate in the successful recovery of the instrument packages. Analysis of the Antarctic data indicated that the tides generated in that ocean did not create as high tides in mid-ocean as had been previously guessed.
An international survey of deep-sea tides was proposed by Munk in 1967, but it was indefinitely postponed because the complex instrument capability was not that nearly ready. Munk's comment to science writer Daniel Behrman was: “You know, there are times I think we may have started too soon and gone too quickly on the deep-sea tide survey. But we have time. At the rate that tidal friction is changing the configuration of the solar system, we have a billion years to finish our measurements before something happens.”[6]
The deep-sea tide measurements by Munk and Snodgrass ended in 1971, and the capsules were modified for studies of internal waves in the ocean. One more capsule was built then and placed on the sea floor for a year for a longterm record of low-frequency fluctuations of pressure, temperature, and water velocity.
Four of the free-fall capsules used during the latter 1960s by the Institute of Geophysics and Planetary Physics for deep-sea tide measurements.
Also concerned with the characteristics of moving water was John W. Miles, who joined the La Jolla IGPP in 1963 from UCLA, and turned to making waves. By means of hot-wire anemometers, he measured the disturbances in the airstream above waves generated in the wind-water tunnel in the Hydraulics Laboratory, in order to determine the transfer of energy from wind to waves. These measurements were compared satisfactorily with theoretical predictions. Miles also undertook calculations on rotating flows of liquids in which Coriolis forces are dominant, and on the resonant response of harbors and bays to earthquake-generated tsunamis.
Microseisms — the minute, continuous quiverings of the earth — have been recorded on seismographs and pondered by geophysicists for years. At the Scripps IGPP Hugh Bradner in the mid-1960s developed a free-fall seismometer to measure microseisms directly on the sea floor. Also interested in these tiny tremors has been Richard A. Haubrich, who in 1970 determined that some microseisms are caused by traveling storms at sea.
Much larger earth motion — that is, earthquakes — became a major study at the La Jolla branch of IGPP during the late 1960s. In 1969 and 1970, following the installation of the seismic station by Haubrich and others at Miramar Ranch, a station was set up on Navy land at Camp Elliott, twelve miles inland from the institute, by Ralph Lovberg and Jonathan Berger. At this recording station a laser-interferometer strain meter capable of measuring the compression in rocks down to one part in a billion was installed, to record strain, tilt, and vertical movement caused by earthquakes, earth tides, ocean and atmospheric loading, or nuclear explosions. In the early 1970s another complete geophysical station was installed, under Berger's direction, at Piñon Flat in San Bernardino National Forest, near the San Jacinto and San Andreas
Seismologist James N. Brune, who joined the Scripps staff from Caltech in 1969, was provided with an office in the IGPP building, and he became a participant in the earth-motion studies. Brune also became an associate director of IGPP in 1973. His interest has been in the total system of earth strain in the general southern California region, from the San Andreas fault southward through the Gulf of California to the East Pacific Rise.
The chain of undersea mountains known as the East Pacific Rise, extending from Antarctica to the edge of the North American continent, is one of the active spreading centers of the world. From its motion, the peninsula of Baja California is being pushed away and northward from the mainland of Mexico. As Brune said, “What happens in the Gulf of California determines what happens in Southern California.” Brune enlisted the cooperation of the University of Mexico in setting up a network of seismograph stations around the Gulf of California, to try to determine the total input of energy into the fault system by the relative movements of the North American and Pacific tectonic plates.
Brune and his associates also prepared an array of portable seismic recorders to transport to the site of earthquakes to record the aftershocks. Brune, Hugh Bradner, and William A. Prothero set up a system of recording earthquakes on the floor of the ocean by means of ocean-bottom seismometers and sonobuoys. These have been deployed both in the Gulf of California and on the crest of the East Pacific Rise about 150 miles south of the tip of Baja California.
Other researchers at the Scripps IGPP have turned their attention to the nature of the solid earth itself, its internal constitution and its oscillations. George Backus, the first appointee to the branch institute, has pondered the geophysical inverse problem: Given the frequencies of the earth's normal modes, what can be inferred about the interior distribution of density and the elastic contents? Freeman Gilbert, who joined the IGPP group in 1961, applied the inverse theory to a study of the earth's normal modes, the mechanical structure of the earth, and the source mechanism of deep earthquakes. Barry Block and Robert D. Moore developed a low-frequency accelerometer to record the normal modes of the earth and to determine the threshold at which surface waves can be detected.
Richard A. Haubrich measured the tilt of the earth by ocean loading and investigated possible causes of the wobble of the earth. He could find no correlation of the wobble with major earthquakes, as had been proposed at times.
Robert L. Parker, who arrived in 1967, set out to determine the electrical conductivity deep within the earth from measurements of the slow variations of the geomagnetic field. Also, working in cooperation with the Deep Tow group of the Marine Physical Laboratory, he investigated the direction of magnetization of seamounts to determine their drag by tectonic movement along the sea floor. To speed up the time required for calculating great quantities of data on magnetism from intensive surveys, Parker developed a method of using Fourier transforms for handling the data. His general computer program, called Supermap, for plotting worldwide geophysical data using any conceivable projection, has proved useful for establishing the relative motion between two crustal plates.
Parker got drawn into an extracurricular project in 1967 while sharing bachelor quarters with a vigorous coffee-stirrer. Continued observations and experiments resulted
A regular visitor to the La Jolla IGPP since its establishment has been Sir Edward (“Teddy”) Bullard, whose name, said Willard F. Libby, is one “to conjure with throughout the world of geophysics.”[8] Bullard entered that world in its infancy when the few participants built, hauled, and repaired their own sometimes hazardous recording devices. “I migrated from physics to geophysics in 1931,” he wrote, “and spent some years learning the techniques of applying physics to the earth and trying to understand the modes of thought of geology. My initial idea was that geophysics should be used to solve specific geological problems, the paradigm being the applications to prospecting for oil. Gradually I realized that, important as such applications were, I was more interested in major problems of earth structure and history.”[9]
In 1949, on a visit to Scripps, Bullard developed the heat-flow probe with Arthur E. Maxwell (see chapter 15). A graduate of Cambridge University, Bullard was assistant director of Naval Operational Research for his native England in the latter years of World War II. He was professor of physics at the University of Toronto in 1948-49, and then director of the National Physical Laboratory in England until 1956, when he became assistant director of
NOTES
1. Letter to Cecil H. Green, 27 November 1963.
2. Director's Report of IGPP, 1965–70, 3.
3. Original proposal, 2 June 1959.
4. Proposal to Max C. Fleischmann Foundation of Nevada, January 1960, 1.
5. Letter to University Vice President Thomas J. Cunningham, 14 November 1963.
6. Daniel Behrman, The New World of the Oceans (Boston and Toronto: Little, Brown, & Co., 1969), 138.
7. Proceedings of the Cambridge Philosophical Society, Vol. 65 (1969), 365–67.
8. Letter to University President Clark Kerr, 30 September 1964.
9. “The Emergence of Plate Tectonics: A Personal View,” Annual Review of Earth and Planetary Sciences, Vol. 3 (1975), 8.
