John M. Crawford (1911-2000) was a member of the team, with William E. N. Doty and Milford R. Lee of geophysicists at Conoco who created Vibroseis. In 1967 Crawford, Doty, and Lee received the SEG Medal Award (now called the Reginald Fessenden Award for their innovation in creating Vibroseis.
John Crawford, known to many as the “father of vibroseis,” passed away 24 February 2000 at the age of 89.
John was born and raised in Madison, Kansas. He received a bachelor’s degree from Phillips University in 1932 and a master’s degree in physics from the University of Oklahoma in 1934. Following graduation, he joined Continental Oil Company (Conoco) as an assistant operator on a seismic crew working the Gulf Coast. Regarding his field experience, John often said that it was invaluable because, “What field work teaches you is never to ask a man to do something that you couldn’t or wouldn’t do yourself.” He carried this lesson with him in future endeavors.
In 1935 he left the “verminous swamps” of Louisiana for Conoco’s Geophysical Laboratory in Ponca City, Oklahoma, with a promotion to development engineer. For the next 15 years, he worked on gravity, magnetic, and seismic problems and their related equipment, data processing, and interpretation. He joined SEG in 1936. In 1951 John was asked to organize and direct a Geophysical Research Group with a total staff of five professionals. John selected W. E. N. “Bill” Doty, Adrian Becker, Hugh Evans, and James Gaebe—all of whom later left their mark on petroleum exploration geophysics. Shortly afterward, these and others became the nucleus of vibroseis, whose conception occurred in August 1952. John said, “I marvel at the caliber of people I was associated with” without acknowledging his significant ability to select these people. The selection of Bill Doty, of course, led to the revolutionary development that became universally used and known as vibroseis. Crawford, as manager of exploration research, selected the researchers, secured the financial support, and provided the direction that allowed vibroseis to develop. He did this while directing other geologic and geophysical research. John’s patents from this period are too numerous to mention.
Crawford’s awards include: Honorary Doctor of Science Degree, Phillips University, 1957; SEG Best Paper in GEOPHYSICS, 1961; President, Geophysical Society of Tulsa, 1963; SEG Distinguished Lecturer, 1963; SEG Medal Award (now known as the Reginald Fessenden Award); SEG Honorary Membership (one of John’s most cherished honors because of the people with whom he shared the award), 1978; Oklahoma Inventor of the Year, 1979; and DuPont Corporation’s Lavoisier Medal for Technical Achievement, 1991.
In addition, John chaired the Geophysical Research Committee of the American Petroleum Institute and was seismic advisor to the U.S. Department of Defense Ad Hoc Advisory Group on the Detection of Nuclear Detonations. John’s relaxation was painting, which he took up at age 53. He became an accomplished landscape artist in oils and watercolors. Numerous juried show awards, exhibits, and sales of some 200 originals (plus uncounted prints) testify to the quality of his work. Three of his paintings adorn the walls of my home.
John is survived by his wife Tonnie, a sister, two sons and their spouses, six grandchildren, and 12 great-grandchildren. Regarding the “father of vibroseis,” Bill Doty said: “Without the combination of talents that Crawford assembled, there might not be a vibroseis as we know it today. Crawford’s leadership, his rapport with management, his knack of encouraging creativity and thinking were just as necessary as all the ideas he contributed. Yet another intangible was the family atmosphere he encouraged, in which we’d pour our first cup of coffee in the morning and ask each other, ‘Well, what can we invent today?’ In this sense, I don’t think that the title of ‘father of vibroseis’ is misplaced at all.”
I first worked closely with John in 1969 when I was given the added responsibility of business manager of exploration licensing (vibroseis and Condepth). From April 1970 until his retirement in 1971, John and I gave presentations on vibroseis—he on theory and application and I on interpretation and exploration significance and results of the recorded data. During one such presentation in Hanover, Germany, Theodor Krey of Prakla Seismos in his introduction said, “If Dr. Crawford is the ‘father of vibroseis,’ then Mr. Laing must be the grandson.” I could not describe my working relationship with John any better than that.
Those who wish to know more about Crawford should read TLE’s December 1983 issue and Appendix B in Vibroseis (SEG Reprint Series No. 11).
Oftentimes - doing something simply because it's right - not expecting it to instantly pay off, turns out to be the economical thing to do. - John Crawford
"He is in his studio" is Tonnie's likely answer if someone is looking for her husband. John Marion Crawford's sanctum in their garage is cluttered and kaleidoscopic. A visitor, dodging easels, light stands and buckets, and focusing through the polychromic confusion, finds the beauty of his paintings astounding. It is even more improbable as the artist, almost by way of apology, admits he first brandished a brush at age 53.
The medium is watercolor - not his first choice but as a result of an allergy to oil bases and no interest in acrylics. And the style? Well, the measure of realism - the jaded blade of grass - has been surpassed. The minute, circular ripple left in the wake of a trout's dive is not forgotten in one of Crawford's immortalized fishing ponds. Perhaps this is a clue to the scientist/artist's meticulous mind.
Crawford's belated embrace of the arts was not at first passionate. He reluctantly attended some classes because of a childhood memory - his father, a happy, active Irishman, suffered a stroke which impaired his mobility. The father, having no sedentary interests, turned inward - and John never forgot it. Thus, later, anticipating his own old age, he determined he would have something to foil the fate of inactivity.
As it is, at 73 the search for inspiration may take the Crawfords as far away as the Swiss Alps. Numerous juried show awards, exhibits, and some 200 originals plus uncounted prints sold, bespeak his work - and his drive. "My idea of hell," Crawford says, "is a place with nothing to do."
Early Years and Education
Even as a boy, in Madison, Kansas, he'd rush to his father's hardware store after school to lend a hand. Merchandising was only a part of the business. "We overhauled tractors, repaired farm implements, built windmills, fixed faulty plumbing, and much more. Years later, as a doodlebugger, those skills came in handy. As far as field work, what I learned from dad was probably more valuable than my college education."
However, in 1932 he obtained his Bachelor's at Phillips University in Enid, Oklahoma, and in 1934 a Master's in physics from the University of Oklahoma. He worked his way through both. While at Phillips he waited tables until the restaurateur realized that John's curtness with patrons made a transfer to fry cook in the kitchen advisable.
Because of his undergraduate performance and the recommendation of his physics professor, Dean Knowles, he got the only assistantship available at OU that year - with a $700 a year stipend. (In a depressed economy, Crawford was the rich man on campus. With money to spare, he even contributed toward one of his sisters' college expenses.)
Upon graduation he joined Continental Oil as assistant operator on a seismograph crew. But his introduction to the work had occurred, ironically - almost mystically - via a seismic event itself a few days before. Crawford says: "My brother and I were walking into his house. Suddenly, we both felt as though someone, or something, had struck us in the small of the back. And sure enough, later that day we got word of a tragic dynamite accident on a Petty geophysical party which had been working miles away [TLE, December 1982]. "The impression that made on me was revived my first day on the job at Conoco. I rode out to the magazine with the shooter. He got into it, lifted a 50-pound case of dynamite, and threw it to me. If I could have fainted without dropping the dynamite, I would have."
That first assignment was in the verminous Gulf Coast - US doodlebuggers' boot camp. Crawford's wife of only one month, Alice, his former laboratory partner at Phillips, had traded a promising career of her own in physics for life in the marshes. But with his promotion in 1935 to development engineer, they moved back to headquarters in Ponca City. Those 18 months in the field, he thinks, added an important dimension to his forthcoming years of office and lab work. "What field work teaches you is never to ask a man to do something that you couldn't or wouldn't do."
Further promotions arrived at regular intervals. Then, in 1951, his boss, Dr. L. F. Athy, asked Crawford if he would be interested in organizing and directing a geophysical research group. "I was elated," says Crawford. "They probably chose me because the gravity work I was supervising was winding down and they didn't know what else to do with me. Be that as it may, they told me I could have four men. Some names were suggested by management and I was pleased with their qualifications. But I had a special request. I wanted William Doty to join my group. Understandably, the operations group where he was working wouldn't give him up. But I fought until they changed their minds - the smartest thing I ever did."
And so, the geophysical development and research department came to life with Conocoans Crawford, Doty, Adrian Becker, Hugh Evans, and James Gaebe. Others would soon join. At the outset, however, the cabalistic question was - what to research? While awaiting the muse, they made themselves available to any explorationist in a quandary. Crawford recalls his team's first contribution: "A division geophysicist told us of an area where he believed there was a structure - but it wasn't showing. The problem, he thought, was that the velocities were changing fast as they went across the structure. That was before the days of velocity control.
"Becker was put in charge of making a statistical study of the area records we had, in order to see how the velocity changed in going from east to west. We came up with a pretty good notion. We made a velocity correction on the map - a wiggle in the contour turned up to be a closed contour. Well, wiggles don't mean much, but closures do. So Conoco drilled a well, and found an oil field."
For a year things continued to be interesting in the research department but not exciting. At least not until August of 1952, after Doty returned from a symposium in Boston. Soon, in Doty's words, "It became electric." What followed - Vibroseis - made history.
Origins of Vibroseis
In February 1960, Crawford, Doty and another researcher, Milford Lee, published Continuous Signal Seismograph in Geophysics. The scientific and pragmatic caliber of their findings deserved that year's SEG Best Technical Paper award. The first license agreement had just been signed and others were looming.
But the beginning and culmination of Vibroseis had both been paralleled by tragedy in the Crawford family. At the early stages of the project's success in 1955, his wife, Alice, died of cancer. Then, as the first license was being issued, his daughter Ann lost a long battle with heart disease.
In both cases, Crawford's grief was eventually assuaged - but not without providential help; his two sons were great sources of comfort and pride. John, the elder son, is now a director of Sandia Research Laboratories, and Jim is a physics professor and department head at Southwest Texas University.
On the passing of his daughter, the senior John also found himself with his 18-month-old granddaughter, Debbie, to care for, but again, providentially with the help of Latane Tracy Crawford whom he had married in 1956. Tonnie, a science teacher in Ponca City for 15 years, was well acquainted with children, including Crawford's. And she switched roles from step-grandmother to mother with ease and grace. The Crawfords' long parenting was recently crowned with Alisha Ann - their first great-granddaughter.
In 1960, Crawford was promoted to assistant manager of research and development. But the added prestige was not all-important to him. "While I was director of geophysical research I wouldn't have traded jobs with anyone in the country, including the President. But the new title involved complex labor relations and red tape. In other words - gone were the days of doing my job while enjoying good one-to-one relationships with colleagues.
"Furthermore, the upcoming wave of management seemed too concerned with the short-term balance sheet. If ideas were not going to pay off immediately there was no use fooling with them. I, and so many colleagues, used to operate differently, because we knew that oftentimes doing something simply because it's right - not expecting it to instantly pay off - turns out to be the economical thing to do. So, after the excitement and the teamwork of early Vibroseis development, my new responsibilities were a big drab and cold."
Pondering what to do next did not reduce Crawford to a meditative slumber. It seems to have had the opposite effect - triggering a whirlwind of professional activity without detriment to family, civic, and church activities. In 1963, while keeping up with his Conoco assignments, he toured the US and Canada as SEG's Distinguished Lecturer on the development of Vibroseis. Simultaneously he presided over the Geophysical Society of Tulsa. If this were not enough, he also attended his first painting lessons. In view of other people's amazement at his gift for making time, Crawford simply jokes: "I didn't waste any getting rich."
Vibrator Seismic Surveys
These signals were manually positioned with respect to each other at about three millisecond intervals. The correlation value was read out on a meter. Each of these values was plotted by hand and the final record was a hand tracing of the plotted points. Thus, a 10-channel, one-second record required over 3,000 individual signal positionings, meter readings, and point plots. All this may seem as arduous as the stacking of the Egyptian pyramids to 3D- and home-computer setters - not so to the Conoco research team.
The excitement mounted. At last, their data points began to systematically match the dynamite profiles right down to the Viola sandstone. "It was one of those Eureka moments," says Doty. "We were shooting for the moon. We didn't know if the earth would cooperate. The big question was the ultimate penetration depth of our acoustic signal that we could recover back from the noise. Yet there it was - 5,000 feet, point by point. We knew from then on that our contribution to seismology was a sure thing."
But the success was embryonic. Each component of the system had to perform vastly better. Vibrators needed greater coupling to the ground and they had to be mobile. The signal they put out had to be controllable. The recording system had to be tailored to the new seismic source. And the correlation process had to be streamlined - pre-compositing of sweeps before correlation, a pressing need. All of which boiled down to making the method cost-effective.
A flatbed truck soon replaced the borrowed water vehicle. It also provided hold-down with its weight via two wedge-shaped attachments at either side of the vibrator assembly. After the vibrating period, the truck would drive forward, enough to release the wedges. The vibrator was then hoisted for transport to the next spot - a slow, awkward procedure.
The following development was mounting the swinging weight vibrator on a trailer. Off-center weights inside the centrally located box provided a thrust proportional to the square of the instantaneous frequency and confined to the vertical direction. In vibrate position, the unit advanced on steel rollers, which also transferred amplitude and phase of the vibrator to the earth. Rubber-tired wheels were used to tow it short distances. For highway travel, the trailer was loaded on the flatbed.
Vibrational output was obtained by causing the direct-coupled vibrator shaft to sweep through the desired frequency band. And in this model the gasoline engine was replaced by a shock-mounted DC motor. The generator was on the tow truck. Although the apparatus was meant to advance on its rollers while the sweep was in progress, this didn't produce the desired results. (The earth isn't sufficiently compacted for signal transmission until a few cycles of vibration occur.) So the unit did not vibrate while moving.
In the summer of 1957 this prototype starred in Conoco's first serious attempt at exploration with Vibroseis. Steel rollers, however, left deep ruts - farmers equated the vibrators with locusts. And all prototypes had one thing in common - they were gargoylian. One Texas rancher described a later model as "a strange monster who raises his posterior in the air and then has a chill."
Outside Conoco, seasoned geophysicists were similarly aghast. In the early '50s, Craig Ferris, then with E. V. McCollum & Co., of Tulsa (TLE, October 1982), was on his way to visit one of their gravity crews in the hinterlands of New Mexico. Something by the road made him stop. "I came upon a strange contraption. I took a good look at it, wondering what that thing could be doing near a geophone spread. Then I saw Bill Doty. I don't know who was more surprised, he or I. Later I learned he thought the secret was out, that I was scouting their Vibroseis crew. He had the crew pick up the gear and move out - to still another remote location. I have to admit, I had no idea what I was looking at."
In April 1958, Conoco ended the hush. At a meeting of the Geophysical Society of Tulsa held in Ponca City, Crawford and Doty spoke about their work of the past five years. Despite their confidence that someday the method would replace totally, or partially, dynamite in exploration, they admitted it was "difficult and expensive and still in the experimental stages."
One of the problems was the apparatus's non-synchronicity, Crawford comments: "Swinging weights rotated in opposite directions. They were off-balance and made a hell of a vibration. We could run them fast or slow, but we didn't know exactly when they'd vibrate. The sweep signal was generated by opening the throttle on the engine to increase the vibrator mechanism to the highest desired frequency. Then, we'd shut off the power to allow the speed - and the frequency - to decrease.
"While this was being done we never stopped recording. And since no two sweeps were ever alike, every time one was generated we had to transmit a separate correlation signal to the recording truck. The amount of record processing was tremendous."
Obviously, the variables were equally awesome. Relatively small weights and practical speeds of the engine could produce seismic signals in the 20-80 cycle frequency range. But since the mechanical displacement of the swinging weights was constant, the generated force was nonlinear. Thus, output at 20 cycles per second would be only one fourth of that at 40 cycles. And so the impossibility of producing two identical sweeps brought home the need to develop vibrators which could be driven synchronously from a pre-recorded sweep signal.
By the mid-'50s a concerted research effort began in that direction. Says Crawford: "We experimented with an electromagnetic transducer, but we didn't get the necessary output. Then, once more, we resorted to something originally designed for other purposes - missile guidance, of all things. It was a hydraulic valve which could take an electrical signal and move high-pressure hydraulic fluid into a cylinder, thus moving it very fast but in a controlled way. Therefore, the cylinder could be positioned in perfect harmony with the electrical signal. Adapting this valve to our requirements, we were eventually able to devise a system by which several vibrators would generate precisely the same signal in unison, and do so in successive sweeps."
The first operational servo-hydraulic vibrator was tested in 1957. And - like the latter swinging weight models - it was truck-mounted. (Why pull a 15,000-lb steel trailer when the tow truck itself is heavy enough to hold down the vibrator?) It had not been done before for good reasons. Frank Clynch explains: "The big problem was isolating the energy source from the vehicle carrying it. Without proper isolation the force of the vibrator would literally shake the truck apart."
In 1958 four servo-hydraulic units were tested synchronously. The following year, the system of multiple vibrators working in unison became part of routine operations. Most of the consecutive servo-hydraulic, rear-mounted models built had an output of about five tons and a usable frequency range of 8-50 cycles per second.
By the 1960s, Vibroseis was out of its infancy - much of the pioneering improvisation behind and licensing underway. Nonetheless, there were major alterations to come before it looked modern (a fleeting attribute) by today's standards.
Improving baseplate-to-ground coupling had been a continued concern. In 1961 a feedback system was developed which minimized the effect of variations in ground contact, reducing distortion in phase of the signal delivered downwards. But for years coupling would remain a problem on hard surfaces - highways and limestone outcrops - which cannot be sufficiently displaced by conventional baseplates, and also in areas requiring a very low frequency energy source.
Then, by the mid-'60s, the vibrator assembly was moved to the center of the vehicle. As a larger percentage of gross weight was placed on the baseplate, a lighter vibrator could be used without diminishing hold-down weight. Center-mounted models were known as "stilt" vibrators because the reaction mass - located above the truck frame - was connected to the baseplate, carried below the drive shaft by long vertical columns. This improved bottom clearance since the baseplate could be further elevated for travel.
In 1967 Conoco's equipment division began construction of Model 8 - the first of a new generation of vibrators. This center-mounted servo-hydraulic unit incorporated extended low frequencies and a nominal output rating of 6.5 tons - 9.5 at peak force. The 4,500-lb actuator was a three-section unit. Model 8 was mounted on an International Harvester M623 6x4 diesel truck with a gross weight of 36,000 lbs. And by 1971 it was in routine use on Conoco and licensee crews requiring high output. Vast scale manufacture of Vibroseis was underway - a lucrative business outside of Conoco, too.
Since the very first prototype, the company's shop had been unable to produce each of the components - often entire units - needed. To list their many contractors would be tedious. Suffice to say that at least two Oklahoma firms of early association became, with Crawford and Doty, and Conoco, namesakes of the vibrator - i.e., George E. Failing Co., of Enid, and Mertz Inc., of Ponca City. Both remain major manufacturers for Vibroseis licensees worldwide. The Pelton Company, also of Ponca City, became a steady supplier of electronic components.
Service to the Geophysical Community
He also was chairman of the geophysical research committee of the American Petroleum Institute, and seismic advisor for the US Defense Department's ad hoc advisory group on the detection of nuclear detonations. In this latter capacity he was with scientists such as Drs. W. Panofsky, Frank Press, Jack Oliver, Hugo Benioff, and F. G. Blake, with Richard Latter - the big-hole advocate - chairing the illustrious panel. Their recommendations are undoubtedly classified material.
Then, early in 1964, Crawford became research fellow. As such, he administered all Vibroseis licenses and handled new negotiations worldwide. "It was pleasant work," comments Crawford, "but it became rather redundant." And again, hyperactivity was his answer to any shortcoming.
In between licensing engagements in England, France, Germany or wherever his method was in demand, Crawford continued inventing. He already held several US patents, including the co-signed Method of and Apparatus For Determining the Travel Time of a Vibratory Signal Between Spaced Points (Vibroseis for short). But in the mid- to late '60s a flurry of new Crawford ideas were filed and patented - Automatic Positioning Device; Floating Support for Seismic Transducers; Chromatography Apparatus; and Process for Transporting Solids in Pipelines, are but a few.
Naturally, a list of kudos had preceded this. In 1947 his old alma mater, Phillips University, elected him to the board of trustees, and in 1957 he was awarded an Honorary Doctor of Science Degree. In 1967, Crawford and the co-inventors of Vibroseis, Doty and Lee, became the third recipients of the SEG Medal Award (later the Reginald Fessenden) for their technical contribution to exploration.
His most cherished award, however, was SEG's Honorary Membership. It came in 1978 - a stellar year with eight recipients, thus the largest group to date. Crawford was on stage in San Francisco's Civic Auditorium with Howard Breck, Milton Dobrin, Franklyn Levin, Harry Mayne, Vincent McKelvey, Turhan Taner, and Sam Worden. Offstage, at someone's suggestion, was a small display of some of Crawford's best work - paintings. "I had brought only four to show my friends what I had been doing in retirement. I had no intention of selling any of them because obviously they were my favorites. But since some were so insistent, I finally relented. And it paid my expenses to the convention."
Crawford had chosen early retirement in 1971. After 37 years with the same employer - Conoco - it was a total divorce from industry except for reading the journals. Since then, he devotes his time to Tonnie, painting, some fishing with friends, Sunday School teaching, traveling and whatever time is left, to rest.
While he indeed divorced himself from the industry, perhaps more conclusively than others, his name remains wedded to his work. Generally, he is considered the inventor - the father of Vibroseis, or Mr. Vibroseis (as some in Conoco called him). Ah - the human tendency to personify an invention, a major battle, a work of art.
But as Crawford knows, only the latter can be a one-man show. Yet, talking about those early and exciting days of research, he drowns the facts in the credit he gives others. "I marvel at the caliber of the people I was associated with" - citing a long roster led by Bill Doty, the man he absolutely had to have in his department.
The admiration is mutual. Per Doty: "Without the combination of talents that Crawford assembled, there might not be a Vibroseis as we know it today. Just as important as the science and the technology that go into a project, are the intangibles - and these are hard to assess. Crawford's leadership, his rapport with management, his knack for encouraging creativity and thinking, were just as necessary as all the ideas he contributed. And yet another intangible that made working with him very special, was the family atmosphere he encouraged - one in which we'd pour our first cup of coffee in the morning and ask each other: 'Well - what can we invent today?' In this sense, I don't think that the title of father of Vibroseis is misplaced at all."
- Laing, W., Ait-Laoussine, N., and Townsend, D. (2000). "Memorials.” The Leading Edge, 19(10), 1140–1141. http://dx.doi.org/10.1190/tle19101140.1
- Proubasta, D. (1983). "John Crawford.” The Leading Edge, 2(12), 16–26.
- Crawford, J., Doty, W., and Lee, M. (1960). ”CONTINUOUS SIGNAL SEISMOGRAPH.” GEOPHYSICS, 25(1), 95–105. http://dx.doi.org/10.1190/1.1438707