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Oral History Transcript — Dr. Adam Dziewonski

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Interview with Dr. Adam Dziewonski
By Frederik Nebeker

January 26, 1994

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Adam Dziewonski; January 26, 1994

ABSTRACT: In this interview, Adam Dziewonski discusses Joe Steim's work in broad band seismology and his company, Quanterra. Topics discussed include: Harvard University; broad band seismic stations; Institut de Physique du Globe de Paris; GEOSCOPE Observatory; Incorporated Research Institutions for Seismology (IRIS).

Transcript

Nebeker:

Let's see, these are pages from the '79 proposal. What Joe said was that the abstract didn't mention the seismograph... but those pages at the back...

Dziewonski:

Okay, let's see. A proposed... Yeah... That's interesting. It seems like things from two different proposals. I don't know whether Joe, by any chance, didn't somehow get...

Nebeker:

Well, what he told me was that this one was where you got the $14,000 matching funds from an alumnus, and you put that into a proposal that I guess you had already planned.

Dziewonski:

Well, the thing is, this is sort of... The title of it is pretty much like my standard proposal, which was, these things had been funded always, because that's what... This is the kind of thing like this, which is a modeling of the earth. It's not theoretical, but basically data interpretation, not involving any construction. It could be... Now, I don't remember... I could probably dig out that this was sort of in addition. But, once we did write a separate proposal...

Nebeker:

Right. Now, here's an '81 proposal, which Joe told me was the one that was not funded.

Dziewonski:

Okay. Maybe(?)... Yes, that's true. My memory now... So, the thing is, I'm quite sure this thing was funded sort of overall, and the only question in my mind would be whether they disallowed, specifically, the money for the... But, yes, I think this is probably our supporting Joe.

Nebeker:

Okay. So that was the '79 proposal, where it was sort of (?)…

Dziewonski:

Then there was the '83 proposal, I guess, which was funded, and then there was one in '85, I think, which was the last one.

Nebeker:

He didn't show me that one...

Dziewonski:

Well, it was essentially a continuation of the one in '83. I probably have a copy of it someplace. That would be the one most likely I would have a copy of, because it was the most recent.

Nebeker:

One thing Joe didn't have, to his regret, were some of the reviews of this one. Any chance you would have those?

Dziewonski:

No, I probably didn't... The first one, it is the one that was rejected, the '81, yes. Because he did seem to remember... This was his proposal. I was sort of nervously sort of like a mother hen, trying to help but at the same time not really expecting I could be critical in sort of technical issues, in terms of... Since electronics is not my specialty, I just sort of felt it was an important and good thing to do, lending my name and... Well, the whole thing was Joe Steim. He was an undergraduate at Harvard, and in his last year, his senior year, he took, actually, two courses from me. One was in applied geophysics, and the other one was in the introduction to seismology. The applied geophysics one, which was the whole semester, he decided the term paper sort of satisfied the requirements and homework, and he essentially built a digital sort of model for measuring the times of arrival, acoustic waves reflected, acoustic waves reflected from some cardboard. Then he decided to apply to graduate school, and it was clear that he had an inclination toward... Well, overall, he was a fairly smart guy, but he was interested in instrumentation, so I asked my old friend, Anton Hales, who retired a long time ago, what would he think that somebody wanting to work on instrumentation should do? Anton Hales felt that that (?)… portable array of (?) instruments would be a very good thing to do, so this is how we got Joe Steim.

Nebeker:

So, you suggested that as...

Dziewonski:

So, I then talked with Joe, had such a suggestion, and so this was why it was added. And just to get things started, knowing that we would not get anything... It was not really practical to go to NSF and ask for money without having anything to show for it. We essentially used some Harvard resources to buy him his first "broadband" instrument, which turned out not to work very well; it actually could not even be used. So, a little bit of time was lost there. So, this portable "broad band" thing really did not take off, and sometime, I think in '82 or so, Joe decided that he'd rather work on this, and he would devote his attention on observatory type of equipment. Then, well, we have this vault at Harvard... Did he actually take you on a tour there? Because that is only two miles from his office, it would be very easy. In Harvard (?) there is an astronomic observatory, but when it was built, oh, in the late 1920s, I guess in 1930 they also decided they should have a seismographic vault. There were some seismographs here in the museum building, but Cambridge got so noisy, tracks and everything, that basically it wasn't very useful. So, they built a vault there, and having it next to an astronomical observatory was always advantageous, because the "timing" of seismologists isn't as precise as astronomers, but... They like to know what time it is within a fraction of a second. So, for a long time, there were very often seismographic stations near astronomical observatories.

Nebeker:

Anyway, it still exists, and this is where, once Joe decided to work on the observatory type of instrument, that's essentially where he started to do most of his work, and eventually, sometime, it must have been like '84, he decided to even move both his house in Shirley, Mass., which is less than ten miles from Harvard, so as to have a shorter commuting distance. Then, that's essentially where most of the things that sort of created (?) were built and tested, so that that's an important place in the whole history. I'm sorry that... Since there's no illustrations involved with it, I guess, but anyway, that's why. It was relatively easy to get started on it, because we did have this vault, actually a very good vault, some fifty feet under the ground level, and (?) being attached to the bedrock.

Nebeker:

What was the advantage in moving to the observatory type of instrument, rather than the portable one?

Dziewonski:

Well, I think part of it was that it was influenced by... Well, there was this concept of very broad-band recording. It was in '82 (or maybe even before that, he probably remembers the sequence better than I), but there is a fellow named Erhard (?)...

Nebeker:

Yes, he talked a lot about...

Dziewonski:

He became quite friendly with Erhard. Actually, they met first time, I think, in '79, and after things sort of his rough road with this portable stuff (couldn't get funding), it seemed like this would be a safe approach. Also, I guess, by '81 or '82, Joe was already four years into his PhD program, and I was getting a little bit nervous that there wasn't all that much to show. This seemed like a fairly safe project that must work.

Nebeker:

How was it regarded in the department for a graduate student to be doing something that was mainly an instrumental…?

Dziewonski:

Oh, I don't think this ever represented a problem. There was a tradition since then, but there was quite a bit... I mean, this (?) ... is called laboratory experiment in geology, so there was a lot of experimentation going on, not in seismology, although, for me, before me there was Professor (?) and he also was involved, but...

Nebeker:

But, I know, though, in high energy physics, there was a lot of resistance to the idea that a graduate student gets his PhD for purely instrumental development; that they wanted to have data involved. But, now it's accepted, and I wondered...

Dziewonski:

Well, I don't think this was an issue. I think actually everybody was very pleased, because there was sort of a perception that our seismology program was very theoretical, and somebody was doing something that involved experimentation and building things that would be a good thing. So, I don't think this ever was a problem. The other thing was about ‘82; Joe more or less decided that he would work on this station, observatory type of equipment, the summer of '82. About that time people started talking, not yet very loud but sort of thinking and talking, that we would need some sort of initiative (?)... accelerated in early 1983, in terms of coming forth with an initiative... Well, actually, let me go back. I think that, because he must have played a role... In the summer of '82, I had some long discussions with Claude (?)... from the Institute of Physics of the Earth, of the Globe, I guess, in Paris. They decided to go ahead with a project which was called "Geoscope," which involved global deployment of long-period instruments at that stage. It was clear that the scientists in France were able to get the project forward that, actually, seismologists in America were almost totally... You have to rely on whatever Darpa decides to put out, for their own purposes. They're very gracious to let you use their data. So, some of us were a little bit irritated.

Nebeker:

That the French were able to do this?

Dziewonski:

Yes, so it was in part, certainly, in my thinking, that something of this sort should take place in the States. So, that was one reason why I felt that this project could be encouraged. And I think it was at this time that Erhard already had this idea of the very "broadband" seismometer, which really was first constructed in Czechoslovakia by a fellow named Plesinger.

Nebeker:

You told me about him, yes.

Dziewonski:

Unfortunately, it was an analog recording and not very well set up to exhibit the power of the method. So, sometime, I think, in the fall of '82 there was a meeting, first in France (?) ... and then there was a meeting in Italy where I spoke with Wielandt and Joe there and we decided to actually move into it. Since there was no money for it, I asked people at USGS whether they could lend us some instruments. They were very good, they lent us (or actually by now must have given us, becfause it had been twelve years and they didn't ask for it!) a set of, well, sort of intermediate period Geotech instruments. Joe started experimenting with those, and it sort of went in stages. First he tried to develop a very stable, "sensitive" zero frequency, or "DC" amplifier, and I think he did actually better on this than a commercial firm like Geotech. Then, the next step was to develop this feedback instrument with a very "broadband" response, and actually, he succeeded by summer of '83. That was demonstrated to work with relatively low-quality Geotech instruments. At the same time, this IRIS initiative was already picking up, because (?)... at about the same time that the first records came out of this very "broadband" instrument, there was, oh, some twenty seismologists from quite a few institutions meeting here at Harvard, trying to get together and put together a plan for a global network. So, the timing was excellent, and it was clear by the fall, when we submitted the proposal, the '83 proposal, that something was going to happen. The proposal, at that time, was well received, and even though we asked for money to build three sets of instruments, they gave us money only for one, I think, and for two years instead of three. But that got the job officially started. This is how we acquired the instruments, (?) instruments (?)… Harvard vote, and essentially Joe... Well, he already developed a recording system. It was this preliminary set of seismographs, but he kept improving them. We went through at least three sort of totally different versions, and eventually, by '85, it was clear, or even relatively early '85, that the thing worked and he gave a talk, together with Wieland, or two back to back talks with AGU in Baltimore, in the spring, May I guess, of '85, and this concept of very broad-band seismology was immediately accepted. It was sort of interesting. It was quite a revolutionary thing, but it was so obvious that it worked that it was accepted immediately.

Nebeker:

When you say it was obvious that it worked — Because of Joe's system, or were there other...?

Dziewonski:

Because of Joe's system, and two things. One is that it's a very nice concept to include in a single data channel all the information, or nearly all the information, to people... Well, anyway, it's "still do-able"... for very nearby earthquakes you still need strong (?) ... dynamic range of the instrument is limited. So, that concept was very well received. It was essentially an extension of the "broadband"... because people already talked about "broadband" instruments, and it was demonstrated that it works through several years of recordings in Germany. But, the (?) there was twenty seconds, and people essentially planned to use a separate channel to record a very long (?)... separate amplifiers, filters and essentially have a separate recording channel. This was demonstrated that you can do it, and in parallel, and at first, it was I think "Gould," or a division of "Gould," which later became Martin-Marietta, they developed the twenty-four byte digitizer, which also was sort of an important part of the "broadband" system, because you didn't need to have a fairly large dynamic range to later extract the signals from these different frequency bands. Of course, I don't know, it was in '85 or '86, but about the same time Joe then figured out how to do himself better digitizers (I think it must have been '85).

Nebeker:

I think he told me that you encouraged him, in the spring of '85, when he gave this talk, you encouraged him to complete the thesis at that point, and that he wanted to do this better job on the digitizer and include that in the thesis, which...

Dziewonski:

Yes, well, you know, at this time it was clear that sort of the revolutionary concept was that the very "broadband" instrument was a novel thing. He had to update it to demonstrate that it worked. At the same time, he actually had access to just single channel, twenty-four byte digitizer from... So... and Joe already was completing his seventh year as a graduate student, and sort of being an advisor who was paying for his support and everything else, I felt it was time to finish. I felt he could have written a very respectable thesis, without building his own digitizer and then developing it. I don't know. We had a little bit of disagreement on these things, because at the same time... It wasn't ever said very clearly, and of course it wasn't clear it was going to happen, but sort of Joe was developing the basis for Quanterra as he was finishing his thesis, and then he was a post-doc for another year, but it was really in preparation, which in some sense... I mean, that's not the objective of the PhD program, which people set up their "companies."

Nebeker:

But it's no black mark.

Dziewonski:

No, it's not, and the "staff" should be happy, because one of their missions is to sort of... No, I think everybody... The way it turned out everybody was very happy. But, along the way, although there are some people here... Well, not here anymore, but were here, who took even longer than eight years to complete their PhD (this is considered long, so people get nervous around six years). Five is sort of standard, six is acceptable, and eight is long. But, as I say, as it turned out, it was all very good, all for a very good purpose, and Joe needed the time... Essentially he did much more than just write the thesis and then go and get himself a job. So, it's okay. One year, I might say that as advisor, I was also quite disgusted, and at some point he essentially felt he needed... And this was true of the "broadband" instrument at this stage, that to do the proper data acquisition system, he needed multi-"tasking" operating system for one of these early microprocessors. And he essentially spent a year writing "multi-tasking" operating system, and I was rather unhappy about it because, again, as you brought out, people... One thing is sort of doing experimental thesis and building some instrument, but the other thing is to become so engrossed in some things that you essentially spend large part of your... essentially writing computer programs, which... Well, again, this is something that turned out quite well, though by the time he finished writing his system, actually, OS-9, which is still used to this day, came out and became commercially available and was much better than what Joe wrote. So, in a way, it sort of was a wasted year except that Joe, by having to do this, became so familiar with how things worked at that level that it was very easy for him to... So, this was sort of a process of education which, again, its applications, even to what at that time would be the subject of his thesis, were not entirely obvious. It's one of these things where everything eventually fell into place, but it wasn't necessarily the easiest road.

Nebeker:

Was it clear from Joe's undergraduate years, I guess his senior year when he was, the last semester, taking two classes from you, that he was going to continue in...?

Dziewonski:

Well, sort of in the middle of this year he had applied to graduate school. He told me about it, I might have actually written him a letter of recommendation, so at that stage... But it was clear that he was capable enough to write sort of standard, I would say, thesis, which did involve finding something (?)... using some digital data which at that time was becoming available. At one stage, actually, two of us wrote a paper which is reasonably frequently quoted, the work was done somewhere around 1980...It took a while to write it up and then get it published, the paper came out in '82, and it would have been quite all right, other than it was clear from the beginning that Joe just wanted to build instruments.

Nebeker:

What paper was this?

Dziewonski:

Oh, it was a paper on measurements of "dispersion of surface waves and measurements of attenuation in the earth."

Nebeker:

You and Joe wrote that?

Dziewonski:

Yes. It was published in the Geophysical Journal in '82.

Nebeker:

I wanted to ask about what records... I'm particularly interested in the Quanterra story. If there are any records that you have kept... Joe had various things. He had a notebook, a lab notebook, which he had kept. He had a few letters, and I've mentioned his NSF proposals, but beyond that...

Dziewonski:

Beyond NSF proposals, I guess I probably would not have had much. There would be some letters, perhaps, which were related, because one of the things that helped us along the way, and helped Joe, was that my very good friend in Italy, (?)... he was also visiting here and we talked to him. He's president of the Italian National Institute of Geophysics, which actually invested as much money as NSF, at least at first, and this allowed us to do another system, which actually was the first system "abroad" of this kind that was operating, and still is operating in Rome. So, but, that gave us a little bit more money. Some of these versions of "data loggers" were actually developed using the Italian money. I may have some correspondence related to this.

Nebeker:

Joe did show me one very nice three-page letter you wrote to that fellow. That was one of the letters he had.

Dziewonski:

I guess Joe probably kept all the records there were, and I probably have copies of some of the proposals. I have a very extensive set of data relating to the beginnings of IRIS, and some of it would pertain to instrumentation. But specifically to Quanterra, probably not, especially since Quanterra was not established until about '87, which already time that Joe's formal link with Harvard was completed.

Nebeker:

Joe mentioned that at one point he was talked to — interviewed — to maybe be chief engineer for IRIS, to do some kind of... the same kind of work... as an employee of IRIS. What I'm getting at is what was the importance of Quanterra as a company? What if Joe had done that, instead of setting up a company...?

Dziewonski:

Well, another option for him was to go and work for Albuquerque Seismological Laboratory, which is where most of his... Well, not most of his, but essentially, his early development was... Well, these were the people who lent us the instruments. Sort of sight unseen, they didn't know what it was all about, and throughout, actually, Joe's career, it would be difficult for me to support him, because they gave us an enormous number of things. They became... Probably some of Joe's best friends, now, live and work in Albuquerque. So, one of the possibilities was... and Joe officially considered... they were very encouraging, that Joe essentially, perhaps, having his salary paid by IRIS... I don't know how it could be done, but they would develop this instrument (that he eventually developed himself) as in collaboration, actually, at Albuquerque. The thing with IRIS, it really wasn't quite clear. Stuart Smith was then president of IRIS, and he did have one long talk with Joe, at which I was not present. I must say, at that time... Well, this was already, I guess, starting the eighth year of Joe's thesis. People were a little bit worried that Joe... I mean, nobody had any doubts that Joe was a very smart guy, it just wasn't clear whether he could finish things, and I must say, I was a bit disturbed by it myself. So, I'm not really sure how seriously Joe was being taken at that stage. That shouldn't be in the history, but...

Nebeker:

Well, what I'm trying to get at...

Dziewonski:

You can talk to me (?)... Professor, which may not...

Nebeker:

Well, what I'm trying to get at is this hypothetical: What if Quanterra hadn't been established? What difference did it make that Joe set up a company, to develop and sell this product?

Dziewonski:

Well, there was another way to do it, with IRIS, and, actually, IRIS pursued this way, because they actually developed the prototype of the IRIS instrument through Martin-Marietta. Joe was a consultant for them, so Joe's instrument was more or less put together by these people at Martin-Marietta. It was a very difficult process, and by the time it was completed somewhere in '88, maybe '89, Quanterra already existed. It wasn't a clear situation, because essentially Joe, after having advised them for a long time, then would be competing with them. So, he was a little bit nervous about some of the legalities, or if what he was doing was legal. Martin-Marietta is a big company, (?)... pick on somebody and destroy them, they could have done it. But, I think that what... So, it was clear that this commercial development, even though it did work — and eventually, I think IRIS bought eight or ten copies of this instrument from Martin-Marietta — that this would be really limited to IRIS. What I think Quanterra did was that they were there when... and Joe had enough know-how to see that these things, with some modifications, and he developed a number of variations of his basic recorder, which were more adjusted to operation at regional network. I think Caltech was one of the first ones, then Berkeley. So, he provided instrumentation to other universities, other countries, as well. So, I think if IRIS could have developed their own instruments, by themselves, built things in-house, for example, through USGS... But I think that would be the end of it. There wouldn't be a commercial enterprise where people could walk in and say, "That seems like a very good instrument, I would like to have ten of those."

Nebeker:

So, the spread of that type of seismograph would have been slower?

Dziewonski:

Yes, so I think the prototype, in a very complex way... the way it developed... because I think also this corporation, Martin-Marietta, sort of really completed Joe's education. He sort of became more aware of what it takes to actually finish something and make it a commercial product, not in the sense of money but in the sense of something you can sell to somebody, and then this is not your worry. If you sort of work on your prototype, which you're using writing your thesis, you can have a lot of loose wires because you know what can be done, but you cannot... So, then he realized that it takes nearly as much to make something that is essentially an industrial product, rather than laboratory (?).

Nebeker:

What have you experienced yourself or heard from others as to how the Quanterra equipment is received today?

Dziewonski:

Well, I guess it was two years ago, but the president of IRIS sort of congratulated me on... well... having been the advisor of Joe, who is clearly the best instrumentalist in seismology in the United States, or in the world. So, I guess that's a compliment. And the fact that basically, with very few exceptions, his instrumentation is bought by people who build these "broadbands" and very "broadband" networks. That is also an expression of the fact that he is very successful.

Nebeker:

Have you been a champion (I think you have) of digitized seismic data?

Dziewonski:

Oh, very much so. That sort of goes...

Nebeker:

That goes way back, I guess.

Dziewonski:

... before Joe's time, but sometime in the late 1960s, actually, one of the sort of... Oh, I don't know great... but, a paper that was actually of some importance in seismology was an analysis of data recorded by analogue instruments from the Alaskan earthquake, one of the largest earthquakes ever, in 1964. They were recorded by this analogue network of worldwide, standard seismograph network, and I made a decision at that time that it's a unique data set, and if we digitized it, we would actually be able to see things that nobody had ever seen. Not exactly by myself, but also working with... Well, I essentially had a technician full-time... These were hand-digitized. Then it turned out we were able to identify many overtones of "free vibrations" of the earth, which actually did put some important constraints on the "radio" structure of the earth. So, it was clear that this could only be done with digital data, and only with a large network. There was some digital data. There was no way, really, to look at free oscillations of the earth without having digital data. Maybe the first observation, which turned out to be wrong, was made by somebody looking at the record and seeing something that was a period, say, of over an hour, then you did that (?) ... then it turned out... I mean there's actually no period of vibration of this short... Actually, this is an aside... but this stimulated Pekaris to essentially redevelop, in some very general sense, the theory of free earth oscillations, and then actually assemble the program to the computers, around 1960, so there weren't too many of those. So, then, in 1960 actually... but then it turned out you couldn't predict this particular observed period, with what were felt were more or less earth "models," and it turned out that a mode like this does not exist. But, when the Chilean earthquake came in 1960 and there were actually instruments that could record it, and there were ways to digitize the records and then analyze in computers, then the theory, which took a fairly long time to develop, was in place. So, these things were interpreted, and it turned out that by and large, although there were some discrepancies, the existing earth models... but they were on the order of 1%... so that the whole thing just needed some adjustment of major change. So, because of this experience... and then we did it once more, again, a very unique, deep earthquake that occurred in 1970, and again it took a year of technicians' time to digitize these things. That turned out to be a sort of important development, even though the initial reason was different. But, we were able to analyze the mechanism of this earthquake in an entirely novel way, and that was again an important development in seismology. So... then... well, the first instruments... sort of the first global network was being built, two separate ones, in mid-’70s and it was very strongly supporting this.

Nebeker:

And you were supporting... digitized data...?

Dziewonski:

To argue for the value of this... because... just to digitize the two earthquakes was two years of work, then the thing was not terribly accurate. I have some records... so, that was relatively easy to argue.

Nebeker:

Were you also pushing for the very "broadband" instruments, when that became possible?

Dziewonski:

Well, in effect, I guess, it turned out this way, but the history of instrumentation, these two networks they mentioned, they were quite separate. There was one which was built by an academic group, from San Diego... It was called "IDA" network, and it was really designed to record free oscillations of the earth. It was only vertical component. The other network was built by, installed and operated by, USGS, the Albuquerque Seismological Laboratory branch, but the way the things were designed, these were narrow-band instruments, and they were short-period and long-period instruments, and each of them were peaked at... Well, one of them was at one second and one was at twenty-five seconds, and it was really related to the detection of nuclear explosives. So, they were not really designed for seismological research involving studies of earthquakes, where you want to reconstruct the (?) function, or, for that matter, the study of structure. So, these were bad. Also, because they were designed for detection of nuclear explosions, they saturated very easily with large earthquakes, which the people who designed them said, "Well, we don't care about that." But, they were criticized anyway, and they were sort of... They used (?) ... but they realized their network was not doing what people wanted. And the IDA group, again, some of the best seismologists work on the "free" oscillations of the Earth, because it's a theoretically rather complex subject, it's an elite, really, kind of research. But, most of the seismologists say "Most of the stuff is useless to us," because these instruments sample the data once every twenty seconds, and then eventually move to one sample every ten seconds, and most of the people are interested in signals on the order of one second, maybe a few seconds, but it was completely outside the range in which they would look at things. Then there was the already recognized, important success of the German "array," the "broadband" array. It was clear that our instruments had to be "broadband," but we also wanted to cover this normal mode part, so when IRIS was forming, I guess, '83-'84, how we were going to do it wasn't very clear. Geoscope, for example, was recoding two channels, a very long period channel and a "broadband" channel separately. So, when it became clear that you could have just one channel, everybody was very happy and as I say, it was one of these things that... This was a very novel idea that did not encounter any resistance. It was one of those things where everybody said, "Well, that's ideal for our purposes, when we do it."

Nebeker:

Yes, it's getting almost universal (?)…

Dziewonski:

Almost instantaneously, even people who gave us hard time on some other occasions jumped at it very gladly.

Nebeker:

Well, maybe that covers the story of Quanterra, from your point of view, unless there's something...

Dziewonski:

No, I can't think of anything right now. Let's see, these are pages from the '79 proposal. What Joe said was that the abstract didn't mention the seismograph... but those pages at the back...

Dziewonski:

Okay, let's see. A proposed... Yeah... That's interesting. It seems like things from two different proposals. I don't know whether Joe, by any chance, didn't somehow get...

Nebeker:

Well, what he told me was that this one was where you got the $14,000 matching funds from an alumnus, and you put that into a proposal that I guess you had already planned.

Dziewonski:

Well, the thing is, this is sort of... The title of it is pretty much like my standard proposal, which was, these things had been funded always, because that's what... This is the kind of thing like this, which is a modeling of the earth. It's not theoretical, but basically data interpretation, not involving any construction. It could be... Now, I don't remember... I could probably dig out that this was sort of in addition. But, once we did write a separate proposal...

Nebeker:

Right. Now, here's an '81 proposal, which Joe told me was the one that was not funded.

Dziewonski:

Okay. Maybe (?)... Yes, that's true. My memory now... So, the thing is, I'm quite sure this thing was funded sort of overall, and the only question in my mind would be whether they disallowed, specifically, the money for the... But, yes, I think this is probably our supporting Joe.

Nebeker:

Okay. So that was the '79 proposal, where it was sort of (?)…

Dziewonski:

Then there was the '83 proposal, I guess, which was funded, and then there was one in '85, I think, which was the last one.

Nebeker:

He didn't show me that one...

Dziewonski:

Well, it was essentially a continuation of the one in '83. I probably have a copy of it someplace. That would be the one most likely I would have a copy of, because it was the most recent.

Nebeker:

One thing Joe didn't have, to his regret, were some of the reviews of this one. Any chance you would have those?

Dziewonski:

No, I probably didn't... The first one, it is the one that was rejected, the '81, yes. Because he did seem to remember... This was his proposal. I was sort of nervously sort of like a mother hen, trying to help but at the same time not really expecting I could be critical in sort of technical issues, in terms of... Since electronics is not my specialty, I just sort of felt it was an important and good thing to do, lending my name and... Well, the whole thing was Joe Steim. He was an undergraduate at Harvard, and in his last year, his senior year, he took, actually, two courses from me. One was in applied geophysics, and the other one was in the introduction to seismology. The applied geophysics one, which was the whole semester, he decided the term paper sort of satisfied the requirements and homework, and he essentially built a digital sort of model for measuring the times of arrival, acoustic waves reflected, acoustic waves reflected from some cardboard. Then he decided to apply to graduate school, and it was clear that he had an inclination toward... Well, overall, he was a fairly smart guy, but he was interested in instrumentation, so I asked my old friend, Anton Hales, who retired a long time ago, what would he think that somebody wanting to work on instrumentation should do? Anton Hales felt that that (?)… portable array of (?) instruments would be a very good thing to do, so this is how we got Joe Steim.

Nebeker:

So, you suggested that as...

Dziewonski:

So, I then talked with Joe, had such a suggestion, and so this was why it was added. And just to get things started, knowing that we would not get anything... It was not really practical to go to NSF and ask for money without having anything to show for it. We essentially used some Harvard resources to buy him his first "broadband" instrument, which turned out not to work very well; it actually could not even be used. So, a little bit of time was lost there. So, this portable "broad band" thing really did not take off, and sometime, I think in '82 or so, Joe decided that he'd rather work on this, and he would devote his attention on observatory type of equipment. Then, well, we have this vault at Harvard...Did he actually take you on a tour there? Because that is only two miles from his office, it would be very easy. In Harvard (?) there is an astronomic observatory, but when it was built, oh, in the late 1920s, I guess in 1930 they also decided they should have a seismographic vault. There were some seismographs here in the museum building, but Cambridge got so noisy, tracks and everything, that basically it wasn't very useful. So, they built a vault there, and having it next to an astronomical observatory was always advantageous, because the "timing" of seismologists isn't as precise as astronomers, but... They like to know what time it is within a fraction of a second. So, for a long time, there were very often seismographic stations near astronomical observatories.

Nebeker:

Anyway, it still exists, and this is where, once Joe decided to work on the observatory type of instrument, that's essentially where he started to do most of his work, and eventually, sometime, it must have been like '84, he decided to even move both his house in Shirley, Massachussetts, which is less than ten miles from Harvard, so as to have a shorter commuting distance. Then, that's essentially where most of the things that sort of created (?) were built and tested, so that that's an important place in the whole history. I'm sorry that... Since there's no illustrations involved with it, I guess, but anyway, that's why. It was relatively easy to get started on it, because we did have this vault, actually a very good vault, some fifty feet under the ground level, and (?) being attached to the bedrock.

Nebeker:

What was the advantage in moving to the observatory type of instrument, rather than the portable one?

Dziewonski:

Well, I think part of it was that it was influenced by... Well, there was this concept of very broad-band recording. It was in '82 (or maybe even before that, he probably remembers the sequence better than I), but there is a fellow named Erhard (?)...

Nebeker:

Yes, he talked a lot about...

Dziewonski:

He became quite friendly with Erhard. Actually, they met first time, I think, in '79, and after things sort of his rough road with this portable stuff (couldn't get funding), it seemed like this would be a safe approach. Also, I guess, by '81 or '82, Joe was already four years into his PhD program, and I was getting a little bit nervous that there wasn't all that much to show. This seemed like a fairly safe project that must work.

Nebeker:

How was it regarded in the department for a graduate student to be doing something that was mainly an instrumental…?

Dziewonski:

Oh, I don't think this ever represented a problem. There was a tradition since then, but there was quite a bit... I mean, this (?) ... is called laboratory experiment in geology, so there was a lot of experimentation going on, not in seismology, although, for me, before me there was Professor (?) and he also was involved, but...

Nebeker:

But, I know, though, in high energy physics, there was a lot of resistance to the idea that a graduate student gets his PhD for purely instrumental development; that they wanted to have data involved. But, now it's accepted, and I wondered...

Dziewonski:

Well, I don't think this was an issue. I think actually everybody was very pleased, because there was sort of a perception that our seismology program was very theoretical, and somebody was doing something that involved experimentation and building things that would be a good thing. So, I don't think this ever was a problem. The other thing was about ‘82; Joe more or less decided that he would work on this station, observatory type of equipment, the summer of '82. About that time people started talking, not yet very loud but sort of thinking and talking, that we would need some sort of initiative (?)... accelerated in early 1983, in terms of coming forth with an initiative... Well, actually, let me go back. I think that, because he must have played a role... In the summer of '82, I had some long discussions with Claude (?) ... from the Institute of Physics of the Earth, of the Globe, I guess, in Paris. They decided to go ahead with a project which was called "Geoscope," which involved global deployment of long-period instruments at that stage. It was clear that the scientists in France were able to get the project forward that, actually, seismologists in America were almost totally... You have to rely on whatever Darpa decides to put out, for their own purposes. They're very gracious to let you use their data. So, some of us were a little bit irritated.

Nebeker:

That the French were able to do this?

Dziewonski:

Yes, so it was in part, certainly, in my thinking, that something of this sort should take place in the States. So, that was one reason why I felt that this project could be encouraged. And I think it was at this time that Erhard already had this idea of the very "broadband" seismometer, which really was first constructed in Czechoslovakia by a fellow named Plesinger.

Nebeker:

You told me about him, yes.

Dziewonski:

Unfortunately, it was an analog recording and not very well set up to exhibit the power of the method. So, sometime, I think, in the fall of '82 there was a meeting, first in France (?) ...and then there was a meeting in Italy where I spoke with Wielandt and Joe there and we decided to actually move into it. Since there was no money for it, I asked people at USGS whether they could lend us some instruments. They were very good, they lent us (or actually by now must have given us, because it had been twelve years and they didn't ask for it!) a set of, well, sort of intermediate period Geotech instruments. Joe started experimenting with those, and it sort of went in stages. First he tried to develop a very stable, "sensitive" zero frequency, or "DC" amplifier, and I think he did actually better on this than a commercial firm like Geotech. Then, the next step was to develop this feedback instrument with a very "broadband" response, and actually, he succeeded by summer of '83. That was demonstrated to work with relatively low-quality Geotech instruments. At the same time, this IRIS initiative was already picking up, because (?) ... at about the same time that the first records came out of this very "broadband" instrument, there was, oh, some twenty seismologists from quite a few institutions meeting here at Harvard, trying to get together and put together a plan for a global network. So, the timing was excellent, and it was clear by the fall, when we submitted the proposal, the '83 proposal, that something was going to happen. The proposal, at that time, was well received, and even though we asked for money to build three sets of instruments, they gave us money only for one, I think, and for two years instead of three. But that got the job officially started. This is how we acquired the instruments, (?) instruments (?)… Harvard vote, and essentially Joe... Well, he already developed a recording system. It was this preliminary set of seismographs, but he kept improving them. We went through at least three sort of totally different versions, and eventually, by '85, it was clear, or even relatively early '85, that the thing worked and he gave a talk, together with Wielandt, or two back to back talks with AGU in Baltimore, in the spring, May I guess, of '85, and this concept of very broad-band seismology was immediately accepted. It was sort of interesting. It was quite a revolutionary thing, but it was so obvious that it worked that it was accepted immediately.

Nebeker:

When you say it was obvious that it worked — Because of Joe's system, or were there other...?

Dziewonski:

Because of Joe's system, and two things. One is that it's a very nice concept to include in a single data channel all the information, or nearly all the information, to people... Well, anyway, it's "still do-able"... for very nearby earthquakes you still need strong (?) ... dynamic range of the instrument is limited. So, that concept was very well received. It was essentially an extension of the "broadband"... because people already talked about "broadband" instruments, and it was demonstrated that it works through several years of recordings in Germany. But, the (?) there was twenty seconds, and people essentially planned to use a separate channel to record a very long (?)... separate amplifiers, filters and essentially have a separate recording channel. This was demonstrated that you can do it, and in parallel, and at first, it was I think "Gould," or a division of "Gould," which later became Martin-Marietta, they developed the twenty-four byte digitizer, which also was sort of an important part of the "broadband" system, because you didn't need to have a fairly large dynamic range to later extract the signals from these different frequency bands. Of course, I don't know, it was in '85 or '86, but about the same time Joe then figured out how to do himself better digitizers (I think it must have been '85).

Nebeker:

I think he told me that you encouraged him, in the spring of '85, when he gave this talk, you encouraged him to complete the thesis at that point, and that he wanted to do this better job on the digitizer and include that in the thesis, which...

Dziewonski:

Yes, well, you know, at this time it was clear that sort of the revolutionary concept was that the very "broadband" instrument was a novel thing. He had to update it to demonstrate that it worked. At the same time, he actually had access to just single channel, twenty-four byte digitizer from... So... and Joe already was completing his seventh year as a graduate student, and sort of being an advisor who was paying for his support and everything else, I felt it was time to finish. I felt he could have written a very respectable thesis, without building his own digitizer and then developing it. I don't know. We had a little bit of disagreement on these things, because at the same time... It wasn't ever said very clearly, and of course it wasn't clear it was going to happen, but sort of Joe was developing the basis for Quanterra as he was finishing his thesis, and then he was a post-doc for another year, but it was really in preparation, which in some sense... I mean, that's not the objective of the PhD program, which people set up their "companies."

Nebeker:

But it's no black mark.

Dziewonski:

No, it's not, and the "staff" should be happy, because one of their missions is to sort of... No, I think everybody... The way it turned out everybody was very happy. But, along the way, although there are some people here... Well, not here anymore, but were here, who took even longer than eight years to complete their PhD (this is considered long, so people get nervous around six years). Five is sort of standard, six is acceptable, and eight is long. But, as I say, as it turned out, it was all very good, all for a very good purpose, and Joe needed the time... Essentially he did much more than just write the thesis and then go and get himself a job. So, it's okay. One year, I might say that as advisor, I was also quite disgusted, and at some point he essentially felt he needed... And this was true of the "broadband" instrument at this stage, that to do the proper data acquisition system, he needed multi-"tasking" operating system for one of these early microprocessors. And he essentially spent a year writing "multi-tasking" operating system, and I was rather unhappy about it because, again, as you brought out, people... One thing is sort of doing experimental thesis and building some instrument, but the other thing is to become so engrossed in some things that you essentially spend large part of your... essentially writing computer programs, which... Well, again, this is something that turned out quite well, though by the time he finished writing his system, actually, OS-9, which is still used to this day, came out and became commercially available and was much better than what Joe wrote. So, in a way, it sort of was a wasted year except that Joe, by having to do this, became so familiar with how things worked at that level that it was very easy for him to... So, this was sort of a process of education which, again, its applications, even to what at that time would be the subject of his thesis, were not entirely obvious. It's one of these things where everything eventually fell into place, but it wasn't necessarily the easiest road.

Nebeker:

Was it clear from Joe's undergraduate years, I guess his senior year when he was, the last semester, taking two classes from you, that he was going to continue in...?

Dziewonski:

Well, sort of in the middle of this year he had applied to graduate school. He told me about it, I might have actually written him a letter of recommendation, so at that stage... But it was clear that he was capable enough to write sort of standard, I would say, thesis, which did involve finding something (?)... using some digital data which at that time was becoming available. At one stage, actually, two of us wrote a paper which is reasonably frequently quoted, the work was done somewhere around 1980...It took a while to write it up and then get it published, the paper came out in '82, and it would have been quite all right, other than it was clear from the beginning that Joe just wanted to build instruments.

Nebeker:

What paper was this?

Dziewonski:

Oh, it was a paper on measurements of "dispersion of surface waves and measurements of attenuation in the earth."

Nebeker:

You and Joe wrote that?

Dziewonski:

Yes. It was published in the Geophysical Journal in '82.

Nebeker:

I wanted to ask about what records... I'm particularly interested in the Quanterra story. If there are any records that you have kept... Joe had various things. He had a notebook, a lab notebook, which he had kept. He had a few letters, and I've mentioned his NSF proposals, but beyond that...

Dziewonski:

Beyond NSF proposals, I guess I probably would not have had much. There would be some letters, perhaps, which were related, because one of the things that helped us along the way, and helped Joe, was that my very good friend in Italy, Enzo Boschi... he was also visiting here and we talked to him. He's president of the Italian National Institute of Geophysics, which actually invested as much money as NSF, at least at first, and this allowed us to do another system, which actually was the first system "abroad" of this kind that was operating, and still is operating in Rome. So, but, that gave us a little bit more money. Some of these versions of "data loggers" were actually developed using the Italian money. I may have some correspondence related to this.

Nebeker:

Joe did show me one very nice three-page letter you wrote to that fellow. That was one of the letters he had.

Dziewonski:

I guess Joe probably kept all the records there were, and I probably have copies of some of the proposals. I have a very extensive set of data relating to the beginnings of IRIS, and some of it would pertain to instrumentation. But specifically to Quanterra, probably not, especially since Quanterra was not established until about '87, which already time that Joe's formal link with Harvard was completed.

Nebeker:

Joe mentioned that at one point he was talked to — interviewed — to maybe be chief engineer for IRIS, to do some kind of... the same kind of work... as an employee of IRIS. What I'm getting at is what was the importance of Quanterra as a company? What if Joe had done that, instead of setting up a company...?

Dziewonski:

Well, another option for him was to go and work for Albuquerque Seismological Laboratory, which is where most of his... Well, not most of his, but essentially, his early development was... Well, these were the people who lent us the instruments. Sort of sight unseen, they didn't know what it was all about, and throughout, actually, Joe's career, it would be difficult for me to support him, because they gave us an enormous number of things. They became... Probably some of Joe's best friends, now, live and work in Albuquerque. So, one of the possibilities was... and Joe officially considered... they were very encouraging, that Joe essentially, perhaps, having his salary paid by IRIS... I don't know how it could be done, but they would develop this instrument (that he eventually developed himself) as in collaboration, actually, at Albuquerque. The thing with IRIS, it really wasn't quite clear. Stuart Smith was then president of IRIS, and he did have one long talk with Joe, at which I was not present. I must say, at that time... Well, this was already, I guess, starting the eighth year of Joe's thesis. People were a little bit worried that Joe... I mean, nobody had any doubts that Joe was a very smart guy, it just wasn't clear whether he could finish things, and I must say, I was a bit disturbed by it myself. So, I'm not really sure how seriously Joe was being taken at that stage. That shouldn't be in the history, but...

Nebeker:

Well, what I'm trying to get at...

Dziewonski:

You can talk to me (?)... Professor, which may not...

Nebeker:

Well, what I'm trying to get at is this hypothetical: What if Quanterra hadn't been established? What difference did it make that Joe set up a company, to develop and sell this product?

Dziewonski:

Well, there was another way to do it, with IRIS, and, actually, IRIS pursued this way, because they actually developed the prototype of the IRIS instrument through Martin-Marietta. Joe was a consultant for them, so Joe's instrument was more or less put together by these people at Martin-Marietta. It was a very difficult process, and by the time it was completed somewhere in '88, maybe '89, Quanterra already existed. It wasn't a clear situation, because essentially Joe, after having advised them for a long time, then would be competing with them. So, he was a little bit nervous about some of the legalities, or if what he was doing was legal. Martin-Marietta is a big company, (?)... pick on somebody and destroy them, they could have done it. But, I think that what... So, it was clear that this commercial development, even though it did work — and eventually, I think IRIS bought eight or ten copies of this instrument from Martin-Marietta — that this would be really limited to IRIS. What I think Quanterra did was that they were there when... and Joe had enough know-how to see that these things, with some modifications, and he developed a number of variations of his basic recorder, which were more adjusted to operation at regional network. I think Caltech was one of the first ones, then Berkeley. So, he provided instrumentation to other universities, other countries, as well. So, I think if IRIS could have developed their own instruments, by themselves, built things in-house, for example, through USGS... But I think that would be the end of it. There wouldn't be a commercial enterprise where people could walk in and say, "That seems like a very good instrument, I would like to have ten of those."

Nebeker:

So, the spread of that type of seismograph would have been slower?

Dziewonski:

Yes, so I think the prototype, in a very complex way...the way it developed... because I think also this corporation, Martin-Marietta, sort of really completed Joe's education. He sort of became more aware of what it takes to actually finish something and make it a commercial product, not in the sense of money but in the sense of something you can sell to somebody, and then this is not your worry. If you sort of work on your prototype, which you're using writing your thesis, you can have a lot of loose wires because you know what can be done, but you cannot... So, then he realized that it takes nearly as much to make something that is essentially an industrial product, rather than laboratory (?).

Nebeker:

What have you experienced yourself or heard from others as to how the Quanterra equipment is received today?

Dziewonski:

Well, I guess it was two years ago, but the president of IRIS sort of congratulated me on...well... having been the advisor of Joe, who is clearly the best instrumentalist in seismology in the United States, or in the world. So, I guess that's a compliment. And the fact that basically, with very few exceptions, his instrumentation is bought by people who build these "broadbands" and very "broadband" networks. That is also an expression of the fact that he is very successful.

Nebeker:

Have you been a champion (I think you have) of digitized seismic data?

Dziewonski:

Oh, very much so. That sort of goes...

Nebeker:

That goes way back, I guess.

Dziewonski:

... before Joe's time, but sometime in the late 1960s, actually, one of the sort of... Oh, I don't know great... but, a paper that was actually of some importance in seismology was an analysis of data recorded by analogue instruments from the Alaskan earthquake, one of the largest earthquakes ever, in 1964. They were recorded by this analogue network of worldwide, standard seismograph network, and I made a decision at that time that it's a unique data set, and if we digitized it, we would actually be able to see things that nobody had ever seen. Not exactly by myself, but also working with... Well, I essentially had a technician full-time... These were hand-digitized. Then it turned out we were able to identify many overtones of "free vibrations" of the earth, which actually did put some important constraints on the "radio" structure of the earth. So, it was clear that this could only be done with digital data, and only with a large network. There was some digital data. There was no way, really, to look at free oscillations of the earth without having digital data. Maybe the first observation, which turned out to be wrong, was made by somebody looking at the record and seeing something that was a period, say, of over an hour, then you did that (?) ... then it turned out... I mean there's actually no period of vibration of this short... Actually, this is an aside... but this stimulated Pekaris to essentially redevelop, in some very general sense, the theory of free earth oscillations, and then actually assemble the program to the computers, around 1960, so there weren't too many of those. So, then, in 1960 actually... but then it turned out you couldn't predict this particular observed period, with what were felt were more or less earth "models," and it turned out that a mode like this does not exist. But, when the Chilean earthquake came in 1960 and there were actually instruments that could record it, and there were ways to digitize the records and then analyze in computers, then the theory, which took a fairly long time to develop, was in place. So, these things were interpreted, and it turned out that by and large, although there were some discrepancies, the existing earth models... but they were on the order of 1%... so that the whole thing just needed some adjustment of major change. So, because of this experience... and then we did it once more, again, a very unique, deep earthquake that occurred in 1970, and again it took a year of technicians' time to digitize these things. That turned out to be a sort of important development, even though the initial reason was different. But, we were able to analyze the mechanism of this earthquake in an entirely novel way, and that was again an important development in seismology. So... then... well, the first instruments... sort of the first global network was being built, two separate ones, in mid-’70s and it was very strongly supporting this.

Nebeker:

And you were supporting... digitized data...?

Dziewonski:

To argue for the value of this... because... just to digitize the two earthquakes was two years of work, then the thing was not terribly accurate. I have some records... so, that was relatively easy to argue.

Nebeker:

Were you also pushing for the very "broadband" instruments, when that became possible?

Dziewonski:

Well, in effect, I guess, it turned out this way, but the history of instrumentation, these two networks they mentioned, they were quite separate. There was one which was built by an academic group, from San Diego... It was called "IDA" network, and it was really designed to record free oscillations of the earth. It was only vertical component. The other network was built by, installed and operated by, USGS, the Albuquerque Seismological Laboratory branch, but the way the things were designed, these were narrow-band instruments, and they were short-period and long-period instruments, and each of them were peaked at... Well, one of them was at one second and one was at twenty-five seconds, and it was really related to the detection of nuclear explosives. So, they were not really designed for seismological research involving studies of earthquakes, where you want to reconstruct the (?) function, or, for that matter, the study of structure. So, these were bad. Also, because they were designed for detection of nuclear explosions, they saturated very easily with large earthquakes, which the people who designed them said, "Well, we don't care about that." But, they were criticized anyway, and they were sort of... They used (?) ... but they realized their network was not doing what people wanted. And the IDA group, again, some of the best seismologists work on the "free" oscillations of the Earth, because it's a theoretically rather complex subject, it's an elite, really, kind of research. But, most of the seismologists say "Most of the stuff is useless to us," because these instruments sample the data once every twenty seconds, and then eventually move to one sample every ten seconds, and most of the people are interested in signals on the order of one second, maybe a few seconds, but it was completely outside the range in which they would look at things. Then there was the already recognized, important success of the German "array," the "broadband" array. It was clear that our instruments had to be "broadband," but we also wanted to cover this normal mode part, so when IRIS was forming, I guess, '83-'84, how we were going to do it wasn't very clear. Geoscope, for example, was recoding two channels, a very long period channel and a "broadband" channel separately. So, when it became clear that you could have just one channel, everybody was very happy and as I say, it was one of these things that... This was a very novel idea that did not encounter any resistance. It was one of those things where everybody said, "Well, that's ideal for our purposes, when we do it."

Nebeker:

Yes, it's getting almost universal (?)…

Dziewonski:

Almost instantaneously, even people who gave us hard time on some other occasions jumped at it very gladly.

Nebeker:

Well, maybe that covers the story of Quanterra, from your point of view, unless there's something...

Dziewonski:

No, I can't think of anything right now.