Reflections on Jack Oliver
Three Lamont scientists who worked with Jack Oliver, who died Jan. 5, 2011, at his home in Ithaca, NY, talk about the deep influence he had on their careers.
From Lamont Research Professor Leonardo “Nano” Seeber:
I first caught the pioneering spirit of Lamont in one of Jack Nafe’s classes in geophysics. He sent me to Jack Oliver to satisfy my curiosity. I remember coming back from that meeting as if I had discovered a new continent. Eventually, Jack was my advisor in a graduate program in seismology.
I had a lot to learn. Perhaps most critical for an aspiring scientist was to become creative. My undergraduate engineering had emphasized performing on tests (which I did not). I expected to be told what to study and how.
Jack told us instead to develop an instrument -- a portable, self-powered seismometer -- that could operate in a remote area and could get there on the back of one person. This for me was a totally new and very exciting challenge. In a year, we had five back-pack seismographs and a truck with a camper that would transport and house them and three seismologists.
Where to and why? I was expecting Jack to come down with a plan. Instead, in one of the classes, Jack announced that it was up to us to come up with a research project for the system. Again, surprise and exhilaration. I made up a plan and presented it to Jack in a few words sitting across his desk -- I can still see his wide smile. "It’s yours," he said. I had to ask him what he meant by that: "The truck and seismographs are yours for the summer experiment."
In one simple elegant gesture, Jack delivered multiple key lessons. His trust transformed my view of my role as a graduate student, member of the research community, and of society. The next time I reported to him was after spending three months recording earthquakes in northern California.
From Lynn Sykes, Higgins Professor Emeritus:
In 1960 I visited Lamont on a Spring Saturday as I was finishing a BS and MS at MIT. My intention had been to work on a PhD either at Cal Tech or Berkeley. After spending several hours with Jack Oliver, however, I decided to attend graduate school at Columbia and Lamont and to work under him on a PhD in seismology, decisions that I have never regretted. If I had not done that, I surely would not have been part of the plate tectonic revolution and the interaction with scientists from marine geology, geophysics and geochemistry. This was surely the most exciting and stimulating time of my scientific life.
Jack started me working on the propagation of short-period seismic waves across oceanic areas and guided me to huge piles of months of seismograms that were arriving from about 15 seismic stations that Lamont had put out around the world in 1958-59 during the International Geophysical Year. That work became my PhD and was published in Bull. Seismol. Soc. Amer. in 1964 with Oliver as co-author. For that work I needed to have better locations of earthquakes in the southern oceans to determine accurate group velocities. I started relocating earthquakes along the mid-oceanic ridge system by computer, found that many events were mis-located by up to several hundred kilometers, and by serendipity that they formed a zig-zag pattern where a major fracture zone intersected the southern East Pacific Rise and offset it by 1000 km. In 1965, Tuzo Wilson interpreted the seismically active and offset part of that fracture zone as a transform fault.
Oliver encouraged me to pursue similar relocations of earthquakes along the mid-oceanic ridge system. A memorable moment for me occurred in early 1966 when James (Jim) Heirtzler and Walter Pitman invited Oliver and me to view a “magic profile” of magnetic anomalies that were symmetrical down to the smallest wiggles for 500 km about the axis of the East Pacific Rise. On seeing their results, sea-floor spreading and continental drift became a reality to us. That led me the next day, with Jack’s encouragement, to start working on mechanisms of earthquakes along the ridge system, which showed that the transform fault hypothesis was correct and by extension that continental drift and sea floor spreading were occurring.
Oliver ran a seminar on deep earthquakes that Bryan Isacks and I attended as graduate students about 1963. Little work had been done on deep earthquakes since the 1930s. That seminar was instrumental in his writing a proposal with Isacks to study deep earthquakes in the Tonga-Fiji region. In 1966, Oliver and Isacks started work on the idea that lithosphere of the Pacific Ocean was being underthrust beneath the Tongan region to depths as great as 700 km using data from that network. The three of us joined forces to summarize those and other evidence from seismology for sea floor spreading, underthrusting of the lithosphere at deep-sea trenches and the newest concept, plate tectonics, in our paper “Seismology and the New Global Tectonics” in 1968.
Jack was very kind in remarks about me in his later book on the plate tectonic revolution.
From Klaus Jacob, special research scientist at Lamont:
I am personally indebted to Jack Oliver, because he invited me in 1968 to come to Lamont for a one-year post-doc term. One year turned into a 42-year stay at Lamont. Even more grateful I am to Jack for how he enticed me to plunge into several new geophysical frontiers.
After my first extended consultation with him at Lamont, he urged me: “If you could come up with a method for how to trace seismic rays through a spherical yet laterally heterogeneous Earth, we really could map out all these subduction zone slabs, and all the other sub-crustal mantel structures associated with volcanic arcs, back-arc basins, and mid-ocean spreading centers; we need a good 3-D seismic ray tracing tool to map out and quantify the Earth's lateral heterogeneities to get a good grip on the dynamic processes that drive the New Global Tectonics.”
He had this fatherly smile when after three months I came up with an algorithm and workable computer program to do 3-D ray tracing in a spherical Earth.
But once the method was born, he urged me to demonstrate its utility in a fascinating test case. He encouraged me to set up a seismic network in Alaska for monitoring the seismic waves emanating from a large nuclear explosion (with the code name “Benham”) that was planned on Amchitka Island, in the central Aleutian Islands. The precise knowledge of location and timing of the explosion would allow high-precision measurement of seismic travel times not only through the regional subduction zone structures in the Aleutian Islands of Alaska, but also would allow the global mapping of anomalously “fast” crustal structures associated with old cratons, and of “slow” crust associated with young volcanic rifts and hot-spot traces. It worked!
Jack's nurturing of young geophysicists, and insistence on high-quality observations in little explored frontiers of tectonically highly active regions of the world, led to a multi-decade presence of the Lamont seismology group in Alaska and its Aleutian arc. He knew how to motivate young scientists eager to explore the world, while holding them to rigorous scientific standards.
He uniquely insisted on and succeeded in combining pure and applied science.