Kuo-Fong Ma (PhD '93), Earthquake Seismologist

Between its small size and its historically active seismicity, the highest standards in earthquake engineering, and maintaining a technological infrastructure at the cutting of earthquake early warning are national priorities for Taiwan. Central to these efforts is Kuo-Fong Ma. Raised and educated in Taiwan, Ma developed an interest in earthquakes and she pursued her graduate work at Caltech's Seismo Lab after completing a Master's degree at the Institute of Oceanography at the National Taiwan University.

At Caltech, Ma worked with her thesis advisor Hiroo Kanamori on finite difference calculations for tsunamis. Following her dissertation, Ma returned to Taiwan, where she immersed herself in the country's deep experience with earthquakes and slip zones. Ma conducted foundational research on the so-called 921 Earthquake of 1999, a calamity which killed thousands of people in Taiwan and which caused severe damage to Taiwanese infrastructure and the economy.

Her many affiliations have included serving as chief scientist of the Taiwan Earthquake Research Center and professor at National Central University, and as founding member and director of the Earthquake Disaster & Risk Evaluation and Risk Management Research Center. Ma is a fellow of the American Geophysical Union, and she has won numerous national awards in recognition of her leading research, including the Taiwan Outstanding Women in Science (TOWIS) prize.

DAVID ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It's Friday, July 22nd, 2022. I am delighted to be here with Professor Kuo-Fong Ma. Kuo-Fong, it's so nice to be with you. Thank you so much for joining me today.

KUO-FONG MA: Thank you so much for the invitation. It's my honor to be interviewed.

ZIERLER: That's so nice, Kuo-Fong. If you could tell me, what is your title and institutional affiliation?

MA: I was a Professor at National Central University for the Department of Geophysics. But just about three years ago, I transferred to another institute called the Institute of Earth Sciences, Academia Sinica, but I stayed adjunct at NCU. So far, for my career, I spent most of my time in National Central University as a professor, and now I've become titled Research Fellow, in a way.

ZIERLER: Kuo-Fong, do you still maintain the kinds of professorial duties, such as supervising graduate students and teaching?

MA: Yes, I still do that, and I still actually have a position in NCU as a director for the Earthquake Disaster & Risk Evaluation and Management Center. That's why I'm somehow adjunct in between, about fifty-fifty almost.

ZIERLER: Kuo-Fong, tell me just as a snapshot in time, what are you currently working on, and what's interesting to you broadly in the field?

MA: I'm currently working on a very exciting project, actually. I don't know whether you know that about four years ago, we had a large earthquake in Eastern- Taiwan, and that's called Hualien. I should say, back to 20 years ago, we had another one, 1999, and we have a very important drilling project. Currently, I actually carry out another drilling project in Hualien. That's what I'm saying now. We would like to have our observatory go through the fault zone in the same time it's so close to the subduction zone, which has the potential to have a mega earthquake like a magnitude 8 kind of scale of magnitude. We have this observatory. We hope to be able to capture more exciting—I shouldn't say "exciting" actually [laugh]—but important signals related to our future earthquakes, and also to understand earthquake dynamics. One more thing to add is for this drilling project, we would like to put into this optical fiber observation, which is very or somehow our agent observation using optical fiber to detect the ground motion. We are installing this to the downhole and also to the surface, first of all, and then another downhole. That would be a very unique setting in the world for the 3D optical fiber observation site.

ZIERLER: Kuo-Fong, I've come to appreciate there are so many sub-disciplines and specialties in geophysics and seismology. What are the main areas of research that you've undertaken in your career?

MA: I mainly name myself a seismologist, so I study seismic waveforms. That's the main field I'm working on. I actually try to understand how the earthquake was ruptured through the waveform. Then from the waveform, I also like to know how this ground motion was moved, and how this might impact to the damage, to the buildings, to the people. I studied basically from earthquake physics to earthquake science to earthquake engineering. At this moment, in addition to this project I was saying for this, really, I provide various solutions. We call it the MiDAS project. I also have another project that tries to put the sensors to the buildings. I would like to study how the ground was shaken. But, at the same time, I want to know how this shaking really impacted the buildings. Partially, we work together with engineering.

A History of Taiwanese Seismology

ZIERLER: Kuo-Fong, many questions about seismology in Taiwan. First of all, tell me about the faults in Taiwan, the areas of concern, both historically and currently.

MA: Taiwan is a small island that we have active for almost every 10 kilometers. [laugh] You understand that, actually, for some distance, you will notice our topography. You might see this ground deformation that's associated with the fault, either on the surface or underground. For the number of earthquakes that every month, maybe we might have a chance to have a magnitude 6, or you feel the ground shaking almost once a couple of weeks, I have to say, especially Eastern Taiwan. The earthquake behavior or seismicity is very high in Taiwan, and it's very dense. Historically, I have to say that because of that, we have a large earthquake. I think maybe like every 100 years, we have two or three damage earthquakes. What I mean by "damage" is to the magnitude like 7. That usually causes very large casualties. Maybe we call it like number beyond 100, that is, we call it a damaging earthquake. Of course, now, I would like to bring the science into this practical exercise, even for the government policy, to reduce the impact. As I mentioned, I do the ground motion to the buildings, and I want to inform our people in Taiwan, saying that earthquakes are something we cannot avoid. But, at the same time, we can do better is to reduce the impact. That can be done in terms of policy and also self-awareness. Maybe like 10 years ago, I published the Taiwan Earthquake Model for the Earthquake Hazard Map, which is actually popular in California. You see California has a map from time to time. But in Taiwan at that time, we didn't really have this open access to really understand what kind of level of hazard you have in your location because there's a lot of impact for that, the housing prices. There's a lot of business behind that. However, it's good now because this open data policy, and also there's social media and all these kind of communications, people actually feel like they have the right to know what kind of risk they are in, and then how can we do better to let them know, at the same time, to give them the solution? They don't just want to know. They also want to know then, "What can I do?" Then government actually becomes nervous because if they have no solution, they don't want to open this message to people. Somehow, it's somehow an internal process, but I think it's going to the right direction. Not to mention one more thing is because now it's a very hot topic about this semiconductor business, Taiwan is one of the most important countries to export and import, and the US is talking about all these chips and so on. Then we are a densely, high-tech company in Taiwan, but we have also this impact from the ground shaking. What I tell them is I try to bring this knowledge to let them know, or either they have issues or they can make a better preparation about what might happen in 20 years, 30 years, 50 years. That's how I try to provide this knowledge—not just to the government, to people but also to those important industry partners. They know what kind of risk they are facing.

ZIERLER: Kuo-Fong, as you alluded to, understanding and preparing for earthquakes is clearly a national priority for Taiwan. What are the ways that government and industry and academia work together, and how do you specifically slot into those partnerships for Taiwan?

MA: I'm glad, actually, we do have a government, social science, and also the industry partners coming to this together. What I have to say is, in the beginning, of course, it's academic studies. When an earthquake comes, we calculate all this focal mechanism, the magnitude. It's the impact like four or five years ago, we had another large earthquake in 2016, Meinong earthquake, and this big impact to Tainan. But actually, the industry partner came to visit me in my office in NCU. The point he was referring as, "We have everything prepared following the guidance from the government. But how come the impact was still so big than what we expected? What's wrong?" Then I began to deliver my knowledge to them. But then, at the same time, I realized what the industry partner needed. They, of course, might not need to know what kind of focal mechanism of this earthquake. What they want to know is, "What's the level of our risk? What is something we don't know?" Because, usually, a science academic might have more knowledge than the policy government made. Usually, science is going beyond the policy. One important thing is those industry partners, they really want to know something beyond the policy because their capital or their value of the company is so big [laugh], they have to understand the risk. That's actually the entry point and important point to really bring in our knowledge to industry partners. Then because of that, then the government is also aware that their policy is behind because to change any government policy or regulation, it takes a long time and, because of that, they're also aware that it's necessary to update this policy or bring in the new regulation in time. That's how it becomes put together. That's something like this in ten years, maybe.

ZIERLER: Kuo-Fong, I wonder if you have a sense of the history of geophysics and seismology in Taiwan, how far back it goes.

MA: Yes, I didn't mention that. But for historic earthquakes, we do, as I mentioned, we have a good record for 400 years. When I was a student in NCU, I was an undergraduate in the Department of Earth Sciences at NCU. At that time, it was called the Department of Geophysics. Then I just learned, actually, geophysics is very new to Taiwan, basically. Let me see how many years. Maybe less than 40 years, 50 years. When I was a student, our professors had something about seismology but they are not trained in the seismology. They are usually trained but, of course, physicists are very important to this field as well. They basically are physicists or mathematicians, however, they bring in knowledge of geophysics. Then we have a very—I forget how to name this in English—but somehow another generation, somehow one couple of generations older. He is the one who actually brings into the government, and say, "Hey, we have an earthquake once every 30 or 40 years. We have to build on the seismic network." That was 1976 or something. I was not around for those at all. But when I got my degree at Caltech, after Caltech, I could come to know what's going on [laugh] for all this history. I have to say we are lucky to have this very wise scientist. He proposed to our government to have this network. At that time, Taiwan's economy was booming. Then, at that time, he said, "That's something we have to pay attention." Also, because of the history of Taiwan, in history, in 1932 up to 1950s, we are colonized by Japan, and then Kuomintang coming to Taiwan after 1949. When I learned of why the earthquake hazard or the impact from earthquakes was ignored for so long, it's because the change of the government every 30 years at that time. Also, a large earthquake comes almost once every 30 years. In the 1980s, the government was here maybe from the 1950s. Of course, also at the time, they don't have enough energy or financial aid [laugh] to do basic science maybe. But, somehow, earthquake impact was not so—got a lot of attention like Japan. That's something related to the history of Taiwan itself. Then, at the same time, for the earthquake once every 30 years, it's also so easy to forget because now when I educate the undergraduate students, they had no idea about the 1999 Chi-Chi earthquake, which for me was such an important impact event in my life. [laugh] I'm senior, but I'm not really that old yet.

ZIERLER: [laugh]

MA: But I'm surprised for the senior in '22, they have no idea about this earthquake. For them, when we mentioned to them why you have to get prepared, they feel like, "Why so?" because 30 years is actually very critical. That's why I often say 30 years is about the time you really get matured. Either you are so young, so you don't remember anything, or you become old. [laugh] Then you forget something. Anyhow, that's how sometimes I always try to tell people that earthquake hazard or the impact, we have to get prepared, and you will need that once in your lifetime. If I go to a public lecture, I will tell them, "No matter what, you will meet it once in your lifetime. If you are lucky enough, you might have two [laugh], two times in your lifetime, so get prepared."

ZIERLER: Kuo-Fong, maybe as a way to let you answer some questions about the culture of seismology in Taiwan, we can start with the issue of earthquake prediction. What has been the history of earthquake prediction, and the confidence maybe in the 1970s, when people were talking about this in Japan and the United States, that this would be a possibility, a scientific reality at some point in the future?

MA: I got my degree in 1993, so I really got into this career after 1993. I have to say, at that time, I didn't really hear that much about earthquake prediction as an important subject to work on. Still, some of them were working on earthquake prediction, and still government always say, "Oh, you need to work on earthquake predictions." But I always mention to them, saying like, "Even if we predict an earthquake, the earthquake will still come. It's not like you predict an earthquake, and the earthquake will not come." Therefore, when I give a public lecture for very wild ideas only, at that time, when you predict an earthquake, you are able to use the energy from an earthquake to minimize the magnitude of the event. Then earthquake predictions become important and useful. What I mean is, like, days or a week. Earthquake prediction is, somehow, not really a hot topic in Taiwan. At the same time, as I mentioned, we have magnitude 6 maybe once every month in the Hualien area. Once in a while we'll see someone from outside like Russia and from Japan, and say like, "Oh, we predict earthquakes. You're going to have an earthquake, magnitude 6, in Taiwan in the next week." We say, "The chance is pretty high [laugh] even if we apply the test." People are pretty calm now, actually, when someone's saying like people are pretty calm for that kind of prediction, from my point of view.

ZIERLER: Kuo-Fong, for you personally, do you believe that earthquake prediction is something that's feasible in the future, or is it simply impossible because the Earth itself doesn't know when an earthquake will happen?

MA: So far, I still feel it's almost impossible. But that's also when I study earthquake physics, I say like, "If you don't know how the earthquake was nucleated, then you have no way to predict the earthquake." So far, at this moment, we still have not yet solved this big question: how the earthquake was nucleated, and why the epicenter is at that epicenter, and why this earthquake stops somewhere, and not going to magnitude 7? Why did it stop at magnitude 5? If these kinds of topics are not yet well-defined, earthquake prediction becomes just by statistics. What I'm saying is while the statistic was not wrong, it's somehow still gives some numbers. It depends on how you really want to learn from this earthquake prediction by statistics or by probability. For a long time, probability, I think that's important. As I mentioned about earthquake hazard for this issue about nuclear power plants or those important infrastructures, we still have to know what's the probability, how active was the fault, even though we still have a lot of unknowns. But, for that part, I think that's important. But I don't name this earthquake prediction. I named it like probability for testing probability for the ground shaking intensity.

ZIERLER: Kuo-Fong, what about earthquake early warning? What is the infrastructure like in Taiwan to give people even a few precious moments before the shaking begins?

MA: That's a very important issue, and we are working on that, and I think, so far, it's pretty successful. The early warning somehow, maybe 10 or 20 years ago, began to be really important, and also Taiwan carry out this. Our government Central Weather Bureau, they issued an earthquake early warning somehow officially, and then we have some app that people carry around that. Again, as I say, people are usually somewhat pretty calm. Some are pretty nervous. It's hard to judge. [laugh] But I put those behind is what I'm going to say is earthquake early warning is important. It's also for this infrastructure, and also for this, as I mentioned, about this industry partner. How to stop the instruments before shaking? That's what we can provide, and that's what we are doing, actually. If we do earthquake early warning like an earthquake in Hualien, come to Taipei or to Hsinchu, those important industry partners, it's about 10 seconds. It's impossible to give the warning ahead of time, but possible to do the automatic shutdown to the machine; not a human being reaction but this somehow automatic process. I think this is important, and then we are working on that and, also, the infrastructure for this elevator for the hospital, and I think our government put a lot of budgetary support to our national lab to really implement these.

ZIERLER: Kuo-Fong, what about earthquake engineering in Taiwan? What are some of the architectural and engineering solutions to minimize damage after an earthquake?

MA: I think we always could have a pretty good team for earthquake engineering. I think for them to do a structure like the bridge and also a damping structure to learn how to have a bigger structure to avoid this long period of ground motion. I think it's always a big issue and discussion in our earthquake engineering partner. But, somehow, I actually work with them closely. But, at the same time, we have a lot of [laugh] conversations. Sometimes, it's difficult. Of course, they also feel like, "You scientists always give this crazy number which we couldn't handle." Earlier, like, earthquake hazard, for example, as I mentioned to you, we published this Earthquake Hazard Map, but the engineer was actually the one not happy with this publication earlier, 10 years ago, when we sat in a meeting to talk about how to make it like open data. They felt like, "The number is crazy. You have this 1g, or 700 gal. That's too large for us in engineering." I was like, "What do you mean by 'too large'? Those are data. [laugh] It's data. It's not like I make up this number." But why do engineers keep saying, like, "Kuo-Fong, please, give the number lower"? I just don't understand. But then later [laugh] I realized, because from their practice, 500 gal, like .5 g, is something they couldn't build. It just has to be a very expensive building to avoid the impact from .5 g. I think something's wrong because we observe .5 g all the time—not all the time but large earthquakes. But not all the buildings collapsed. That's how I began to talk to them about this fragility curve, how this scientist goes together with engineers. I talked to the Central Weather Bureau about whether they would like to change the intensity scale because, earlier, they only do the intensity for the peak ground acceleration. But damage is not just from peak ground acceleration. It actually maybe comes from velocity. They changed this intensity scale two years ago. Somehow, I think the dialog was intense, but the solution is good.

ZIERLER: Kuo-Fong, I'll ask this question on the basis of you being a scientist generally, and a seismologist specifically. Are there opportunities to collaborate with seismologists in Mainland China? Given all the geopolitical tensions between Mainland China and Taiwan, what are the opportunities, at least for scientists, to work together?

MA: I have to say before this now slightly more difficult time [laugh], maybe even from COVID, I don't know, but before really the tension, we worked with the mainland Chinese closely. For the past 20 years, we had this over Taiwan Strait meeting once every year. Even for our university, we have our annual meeting with USTC in China. I don't know how many times I've visited China, not to mention all these colleagues I know. I've known them for so long. Some of them are classmates in the US, actually. The science part is not a problem at all. It's just now the tension's become so tight, and that becomes tricky. There's no rule to say you cannot, but I just don't feel I want to. [laugh] Those are my personal feelings. But, before, and of course, they are still my good friends if we meet each other, but I just don't feel like it really has to deal with this exchange program that is somehow people can do that.

From Taiwan to the Seismo Lab

ZIERLER: Kuo-Fong, let's now go back and establish some personal history. Before you got to Caltech, as an undergraduate at National Central University, were you interested in earthquakes and seismology even then?

MA: That's very interesting because in Taiwan, how we get into university is not like what you want to be. We have a national entrance exam. Then when I go to the entrance exam, I don't know what kind of score I might have, so I just have to put down everything in my wish list. I don't know my score yet. I also don't know how many are better than me, so I might not be able to get into the department I want to go to. At that time, I put on this wish list, and I like physics and mathematics since I was at high school. I don't know why. I just like math and physics, so I put on every math and physics for every national school because, in Taiwan, the national school is on the top, and then private schools. I just put like all the physics. I hate chemistry, so I did not put any chemistry. [laugh] I dislike engineering. I just physics and math, so I put down all the physics. That's when I see this field of geophysics. I remember I asked my older brother, he was a physics major, and I asked him, "What is geophysics? I never heard of it." Then my brother said, "It's just one kind of physics." Anyway, I said, "Oh, OK." Then I put it down, and then I became a geophysicist at NCU. [laugh] I had no idea what geophysics was. [laugh] I don't know I want to study earthquakes. I had no idea at all.

ZIERLER: What kind of opportunity did you have for laboratory work during the summers as an undergraduate?

MA: For an undergraduate doing an intern in the summertime, I actually took an internship in Academia Sinica, at the institute I'm in now. That professor, he is a seismologist. The reason I go into earthquakes is also to be in geophysics. First second, second year, we studied a lot of geology, introduction of geology, mineralogy, petrology, of course, also physics and so on and math. But I'm not so into those things. I'm still good in taking the grade. I study hard so some of my grades are nice. But I dislike geology, so I was like, "I don't know what I what to be." I was not so into those until I took the course in seismology with all the equations. Then the instructor, I mean, the professor said, "I feel so sorry to show you all the equations on the board." I was like, "Why did you want to say sorry? I miss this so much. [laugh] I like equations." I began to feel like if I want to stay in this major, I will go for seismology. I will study earthquakes, and then I go to intern at the Institute of Earth Sciences for the earthquake P-wave picking for location to locate the earthquake. That's how I began my career in that time at NCU.

ZIERLER: Now, tell me about when you transferred to National Taiwan University, being at the Institute of Oceanography. Were you specifically interested in seismology in the oceans?

MA: That's also because Taiwan is so small. At that time, the Institute of Earth Sciences is on the campus of NTU. I studied at that institute. It's just it was closer to my future advisor at that time. That institution, I have to say, is by name, but they still study the Earth. I still studied earthquakes even in the Institute of Oceanography. But, of course, in the same time, I still studied some oceanography as a requirement. The reason for that is for my master's degree. I also feel for the master's, it's good to have a different environment, so I transferred to another university—not transferred; just go to another university for this degree.

ZIERLER: Now, by the time you had gotten your master's degree, were you already committed to getting a PhD beyond Taiwan? Were you looking specifically outside of Taiwan for a thesis?

MA: Because in Taiwan, we have a master's program, and then PhD programs, we usually always just go to the master's, and then we think about what's the next. I have to say I have a lot of influence from my older brother. He is a physics major, and he became an engineer. But he taught me, "Kuo-Fong, if you do science, you have to go for a PhD. Otherwise, you will just follow people's idea, not your own idea. If you want to be a scientist, you have to go for a PhD. But if you want to go for a PhD, you have to go to the top school." [laugh] Actually, I was 20, 24, 20-something. I had no idea. Then we have to do this English TOEFL exam. It's not easy just to go abroad for a PhD because, also, the scholarship, you have to apply for the scholarship. You have to go for the TOEFL exam. You have to go for GRE exam. That's a lot of preparation, so I was in between like, "Should I go or not go? Oh, maybe I'll take some exam, and I will see." That's how it happened.

ZIERLER: Now, when did you first hear about Caltech and the Seismo Lab? Who told you about it?

MA: [laugh] That was so funny. I have no idea. In Taiwan, at that time, of course, Taiwan is not really a popular thing, not to mention there's no social media or anything. It's my professor, as I say, Professor Wang at Academia Sinica, in his class, he kept mentioning two names. One is Hiroo Kanamori, who is from Caltech. The other one is K. Aki from USC, at that time. In the class, he kept mentioning them, and they're like God, and I'm like why? I just felt that my advisor just admired them so much. He kept saying, like, "They are the ones." Somehow, he named this moment magnitude. But Caltech was so far for me. It's just reading in a paper, "Caltech, someone." We'd read and see, "OK, Caltech." I never dreamed I could be one of them. I actually don't think I can be. It's just when I applied for school and, luckily, maybe I was pretty good in my performance, and I applied for school and, usually, in Taiwan, at that time, usually, maybe apply to 10 schools. We have three in the bottom, feel like secured, you will go. Maybe the same thing in the US. I think everyone has this kind of policy. You have the three secure positions, and then the fourth somehow in between, and three was impossible. But, anyway, I tried. Caltech is one of the impossible. I just tried. I still remember when I received the admission from Caltech, I was running to my advisor's office. In the hallway, I just screamed all the way to the office, and said, "Oh, my god, I got accepted by Caltech." He was so excited. He said, "You have to go to Caltech for sure," because, at that time, I was thinking of going to USC in the beginning, because Caltech is the last offer. I still remember where I ran in the hallway [laugh] when I was 24, and I usually was so active so I was just screaming and yelling in the hall. [laugh]

ZIERLER: Kuo-Fong, had you ever been to the United States before?

MA: Of course not.

ZIERLER: How was your English up to that point?

MA: [laugh] That was so funny. I keep saying to my students, "My first year in Caltech, in the very beginning, people considered me as a very quiet person because I couldn't really speak that much English." In the hallway, they used to say, like, " How is everything going?" I was like, "Why do you keep asking me where I'm going?" [laugh] It's at my institute. Their questions don't meet. Then I go like, "Oh, it's just hello." Before hello is "How do you do?" "I'm fine, thank you." That's how we learned. It's a lot of interesting stories behind. I just remember they kept saying, "Terrific." I was like, "Why do people keep saying this word? What is this word? I have to check in the dictionary [laugh] to understand what they mean by 'terrific'." A lot of interesting things.

ZIERLER: Kuo-Fong, what sticks out in your memory when you first arrived at the Caltech campus?

MA: I actually was shocked by the history. I have to say my knowledge was so narrow so I really don't know how much Caltech had built in before in the history. I learned, actually, by those stages and those things one-by-one. My first impression was not really the campus. It's how I meet Professor Hiroo Kanamori because he was like a god, so when I met him, I don't know how to speak because it's like a god in front of you.

ZIERLER: [laugh]

MA: [laugh] But, actually, he is so kind and easy. He explained everything in detail to me. Also, at the time, I just felt like I came to Caltech. I want to work with you. It was so simple. But, actually, maybe one or two years later, he told me, "Yeah, you can work with me, but I don't need to say yes, actually. [laugh] I can decide." But, at that time, I just feel like I want to work with you, so you have to take me. Like, I had feelings that because he took me as his student, that's such an honor.

ZIERLER: Kuo-Fong, relative to your other fellow graduate students, how well prepared were you coming in, coming right from the master's degree?

MA: When I came to Caltech, I have to say, everyone is a genius in the class. We have to take some courses in physics and mathematics, and so on. I still remember in the math class, I told you, I mentioned that I like math so much. Usually, if there's any tough question in class, I am usually the only one to solve that question when I was an undergraduate student. But when I was in Caltech, in the math class, I struggled so much to give the answer. Then I realized everyone all hand in their answers. It's just like I'm the only one struggling, [laugh] that kind of feeling. Then I still remember in that class that a Professor Cohn, a very high energy class, and the professor had all these complex equations and so on. There's one Indian student. I have to say my English was not that good at that time, so I don't understand that student's questions at all. But the professor kept saying like, "You will be a superstar. You will be a superstar." I was like, oh, my god. I don't understand the professor. I don't understand the student, and the professor kept saying he will be the superstar, so what am I going to do? [laugh] It's just a lot of impact, but I enjoyed it so much, just to see how everyone can go with all the problem they solve. Then come to the graduate students, to come back to the Seismo Lab, we had like five or six.

At the same time, we worked together for all these questions and so on. For research, I have to say, I feel fortunate I have my Master's degree, so I know how to do research in a way. If I didn't get any master's degree, and then come to Caltech directly, I don't think I can finish that smoothly because in Caltech, of course, the supervisor gives good guidance, but they don't teach you from scratch. Usually, you have to go your own way. I was lucky enough. I had my master's degree, so I have the experience of doing research, so my connection to the PhD diploma or PhD degree started smoothly. I saw my classmates. Some of them are struggling. Of course, we worked together. But then I can see the differences, and I would think about myself. If I didn't have my master's, I might struggle like them.

ZIERLER: Kuo-Fong, being in the Seismo Lab in the late 1980s and early 1990s, what were some of the big ideas at that time? What were the big research topics that the professors were working on?

MA: At that time, the instrument became broadband instruments. Earlier, I think it's only like narrow or analog data; not digital. I was lucky enough to really get into the digital era during my research career. Even the terminal has windows that we can just operate with windows. I don't need to go to those punch cards. Sometimes, people told me about the program. You have to have a stack of punch cards. I was lucky enough I didn't go through that. It was keyboard already. I remember my first year into Caltech, Hiroo Kanamori showed me the record for the 1988 Pasadena earthquake, the waveforms, beautiful waveforms. I had no idea but it is beautiful, because I never see anything ugly because I don't see ugly yet. [laugh] I don't know broadband is not fancy because in Taiwan, at that time, we don't really have the waveform. I think we had only the analog at that time, like a drum, and then you have this pen get into these waveforms. I think for the late '90s, that becomes the digital era, so everything becomes digital, and the instruments become broadband. You can really access the data from site to your office. My advisor showed me that he feels so excited, but I feel nothing, at that time. Only like two years later, I said something like, "Now, I understand why he was excited, because before, the record looked so ugly, not high resolution, and it was difficult to analyze the waveform." For my time, it was a good time for the broadband instruments, so we are able to determine the focal mechanism using waveforms rather than just the arrival time of P-wave, the first motion. Also, during my PhD program, also the time that we began to work on finite fault, we understand the earthquake was not just a point but a dimension. Then using the waveform, we can map how much slip on the fault, even though we didn't really go into the site. But we are still able to measure the waveform, and then maybe how much fault was slipped during the earthquake, and that was amazing. I didn't know that was amazing until like five minutes later. [laugh]

ZIERLER: Kuo-Fong, would Hiroo Kanamori, was he set to be your PhD advisor from the beginning, or was that a process for you?

MA: When I came to Caltech, first of all, I had two academic advisors. I think that was from the Seismo Lab division to have Clarence Allen and Don Anderson as my academic advisors. I think at that time, it's somehow what kind of courses I'm going to take, and so on. But I just go to Hiroo at that time. It's because, like, I just want to work with you. Even for the first year, we are not really doing for the PhD program, I mean, the research topic was not yet defined. But, somehow, we have so many projects along with the course. With that class, I go to Hiroo Kanamori to say, "I would like to do the project with you," and then that's how it began. Then the second year, as I mentioned, we had to have these official advisors in the—I don't know—maybe in the record, and so I go to Hiroo, and I ask him whether he would like to be my advisor. Then that's how, as I mentioned, he said, "Yeah, I can be your advisor, but I just want to let you know I can also say no," [laugh] because I somehow just feel like, yeah, you will be my advisor automatically. I was so naïve.

ZIERLER: Kuo-Fong, I've heard in earlier generations, people who were at the Seismo Lab in the '50s and '60s, before data sharing became really normative in seismology, when the Seismo Lab had data, that was almost proprietary that others needed to come to the lab to access. What was your sense when you were a graduate student? How decentralized was data by the time you were there?

MA: I think I didn't really experience that period because when I was there in 1988, we already had this data archive like IRIS. Is that IRIS or WWSSN? I forget what is this series. But I remember at that time, I can just get the data. But maybe I was not from outside, so I don't know how outside people would get the data. [laugh] I don't know. I just feel like when I wanted to do the data, the data is there. [laugh] Maybe the experience would be different if I'm not in Caltech. I don't know whether people to get the data have to go through all this process. I don't know.

Tsunamis and Hiroo Kanamori

ZIERLER: Tell me about developing your thesis topic.

MA: That's also another interesting topic. I worked on tsunamis in the beginning. The reason for that is I do the finite-difference for my master's degree, and then Hiroo Kanamori came to me and said, "Kuo-Fong, you do the finite difference calculation. Do you want to work on tsunamis?" I was, like, I even don't know the word "tsunami" [laugh] actually. I couldn't recognize this vocabulary. I was like, "What is this? Oh, tsunami." Then I find, yeah, it's the finite difference. I can do the calculation. At that time, there's another professor, Kenji Satake. He's now a director of ERI. He was a postdoc and, of course, Japan works on a lot of tsunamis. For me, I'm so easy for all the topics, so whatever they feel like, "Kuo-Fong, do you want to work on that?" I say, "Oh, sure." Then I do that. I do that and then, at that time, in 1989, Loma Prieta earthquake that generated a small tsunami, so I used that tsunami record to study the fault, and then the Kalapana earthquake in Hawaii. I often say whether I feel lucky or in another way, my thesis is a sequence of Californian earthquakes. I was there in 1988, and there's the 1988 Pasadena earthquake. Then when I finished, the 1989 Loma Prieta earthquake. When I finished in 1989, Loma Prieta, in 1992, the Landers earthquake. But 1989 and 1992, there's a couple of others, 1991, the Sierra Madre earthquake. When I finished the Sierra Madre earthquake, I was like, hmm, maybe I should study something else. Then Hiroo said, "Oh, you can work on the 1975 Kalapana earthquake in Hawaii for tsunami." I said, "OK, I'll do that." When I finished in 1992, the Landers earthquake, but when Landers earthquake came, I talked to—and I was talking. I would say, "Don't come again. I want to finish." [laugh]

ZIERLER: [laugh]

MA: I want to finish my degree. No more big—there are other things. Just finish. I want to finish and get my degree. I talked to Hiroo and said, "Do you think it's about time for me to get my degree?"

ZIERLER: [laugh]

MA: Then he said, "Yeah." Landers earthquake, I did not finish it all. In 1995 in Northridge, I become feel like, somehow, I feel like, oh, I miss this earthquake. I should study that one. After 1995, it becomes silent for so long. My time there, my every chapter is one earthquake in Southern California in sequence.

ZIERLER: Kuo-Fong, I'm curious, with all of your focus on Southern California, did you see opportunity to extrapolate what you were learning in that region to what was happening in Taiwan? In other words, when is the research approach really locally focused, and when can you make those broader determinations about earthquakes on a worldwide scale?

MA: Actually, that's very important. My experience in California in Caltech is how I can explain myself in Taiwan. I have to go back again. When I got my degree, I talked to Hiroo saying, like, "I only want to go to Taiwan or stay in California," because I have to fly to Taiwan once every year. I couldn't go to East. I know you are not in New York. [laugh] I couldn't to the East Coast. That's too far, so either in the West Coast or go back to Taiwan. Then he said, "Taiwan has such an important network." As I mentioned, he convinced our government to have the Strong Motion Network in Taiwan since 1992. Then Hiroo Kanamori told me, "Taiwan is the only place to have the network before the large earthquake. Every country always has a network after the earthquake because [laugh] the budget always comes after the earthquake." Then Taiwan is so wise to have this important network. It's a good time to go back. Of course, NCU is also very keen for me to come back, so they give me the title to reposition immediately. I talked to Taiwan, as you mentioned, about the data. I actually feel like it's important to share the data. Then our government also learned, like, the data sharing is important.

For my time, for my generation, I was also lucky enough that when I access data from the Central Weather Bureau, I don't need to wait. I can just access the data directly. I did it before. Some people just, like, five or six years older than me, they experienced all the hard times, like, "I studied earthquakes. I couldn't get the data. How can I do? I made my own data, so I transfer to exploration." [laugh] That's what my colleagues say. Then, also, at the time, when I came back to Taiwan, I was like I don't know anything about Taiwan tectonics, even though I studied undergraduate in Taiwan but I was not so into that, so I didn't really put that into my brain. I just do that in the exam rather than really into my brain. When I came back to Taiwan, all my thing is California, the active faults, not about Taiwan, so I learned gradually. But, at the same time, that knowledge I learned from Caltech—like waveform analysis, how important to share the data, how can we learn earthquakes more from the waveform—I implemented all that into Taiwan. That's very important.

ZIERLER: Kuo-Fong, who besides Hiroo Kanamori was on your thesis committee at Caltech?

MA: I have to say some people I've forgot. But Clarence Allen and Don Helmberger, and I think there's one from planetary sciences—I forgot his name—Murphy maybe, and also Don Anderson, I think, that's in my committee. But I remember more is for my qualifying exam. At that time, my English was not so good yet, and we had to have this qualifying exam as a PhD candidate one year after I entered Caltech. That was October, and I was in Caltech in '89, so I had the defense in the '90s, October, just one year. Then the question was so tough. What I mean by "tough" is it's not something I present in the class. They give me the question like, "Kuo-Fong, you studied Q. You studied attenuation. Tell me, how could you determine the Q?" I was like, "What?" [laugh] that kind of question. Also, they said, "Kuo-Fong, if I have this fault, and I give you the founding, what are you going to do?" all this kind of questions. But I think my answer may be all right, so I passed. But, somehow, I was so nervous and intense at that time, and that's actually more intense than my PhD defense. [laugh]

ZIERLER: What would you say some of your key arguments or contributions were with your thesis?

MA: For my thesis, I think, the important thing is, as I mentioned for the tsunami and the broadband, I actually have two parts. One is the tsunami, and one's the broadband waveforms inversion. One thing is for the broadband waveform inversion, at that time, to provide a waveform to determine the focal mechanisms, and to understand what's the relationship with the active faults. That's somehow an important topic using one station to determine all these mechanisms. For the tsunamis, we are able to pin down the tsunami waveform to the source, like Kalapana earthquake, to understand that tsunami generation is due to a volcano eruption or an earthquake in 1975. For the Loma Prieta earthquake, we tried to understand the tsunami in Monterey Bay is due to the change of the fault or the submarine landslide in Monterey Bay. It's certainly not really a big impact but, somehow, it gives some answers toward the understanding of some phenomena.

ZIERLER: Kuo-Fong, did you ever give thought to remaining in the United States, pursuing a career here?

MA: At that time, as I mentioned, I wanted to stay either in California only, the West Coast, or Taiwan. But, at the same time, I have to say, at that time, I had a baby already, I have a family, so it's difficult to move around. I see people doing the postdocs here and there. I feel it's difficult for me. I need to have a more permanent location, and also only, as I mentioned, to Taiwan or on the West Coast. Here, also, Taiwan is a great opportunity for me in the university, so I decided to come back. I still feel I made the right choice to come back.

ZIERLER: Kuo-Fong, as a woman, as a foreign-born woman in the Seismo Lab, did you ever feel not part of the club, if you know what I mean?

MA: Yeah, I know. But—I don't know—I feel I was quite happy there. I don't really feel any discrimination or, somehow, unfriendly treatment. I have to say all the Seismo Lab staff were so kind to me. Even Hiroo Kanamori's secretary, Ann Freeman, we still have a connection.

ZIERLER: Oh!

MA: She still gives me a birthday wish every time, and I still see her all the time. My daughter was born when I was in the Seismo Lab. My daughter even goes to see her straight away; called her American Grandma. It's just this close. All the secretaries, they are so nice to me, and it's just like friends.

ZIERLER: Tell me about your first faculty appointment back in Taiwan.

MA: My first position, as I mentioned, is at NCU, and I became associate professor right away, so I never really go through a postdoc. I didn't go through assistant professor. Now, actually, also, at that time, they told me that I was the last generation of associate professors immediately because, at that time, we didn't have the assistant professor check our type yet. It started with associate professor. Also, people don't feel it's necessary to go through the postdoc, so I became associate professor right away. I was only 29 at that time, so when I was in class, I actually forgot I'm a professor because I was 29. [laugh] I still give this joke to my colleagues or to younger students or female scientists. I remember, I went to a meeting, and then the dean didn't know me yet. But I'm a female sitting in the front, and then he just gave me a stack of papers, and said, "Distribute all the paper out," so they considered me as a secretary. I was sitting there feeling like, "Oh, do I have to do that?" They said, "Do that." I said, "OK." Then they found me, actually realized I'm faculty. It's just this kind of story because a female is so easy to put into that category. Not to mention, when I was a department chair, people would come in, and they'd consider me as a secretary. They'd discuss things, and then they'd say, "Oh, I need to see your chairman." I said, "I am the chairman." They're like, "What?" [laugh]

ZIERLER: [laugh]

MA: Because, at that time, I was 35. [laugh] I actually enjoyed this interaction—

ZIERLER: [laugh]

MA: —until the people don't have that reaction. Then it becomes they'd be like "Oh, yeah, here's my seniority." But, at that time, if I go to some school, and I'm coming for the exam, they'll say, "Oh, are you a student?" I'll say, "No, I'm the professor."

ZIERLER: [laugh]

MA: But no more. People don't ask that at all—not anymore.

ZIERLER: Kuo-Fong, as you mentioned, all of your research focus at Caltech on Southern California, coming back to Taiwan, what did you need to do to get up to speed about seismicity and tectonic shifts in Taiwan?

MA: Actually, there's some struggle in the beginning. It's because when I was at Caltech, I feel science is something you don't need to—there's no territory. There are many different territories but, somehow, people were bringing their knowledge freely. But when I came back to Taiwan, I find out I have no position. What I mean by "position" is I don't know what I can focus on because, somehow, they have some territory not clearly defined. They would say, "Oh, people are working on tectonics. Some people are working on earthquake focal mechanisms. Some people are working on earthquake location." If I do something, somehow, it seems like I'm stepping on someone's feet. In the beginning, I actually felt a little bit of a struggle as I don't know where I can really bring in all my knowledge or what I want to study. But, gradually, I realized, in the beginning [laugh], somehow, people will say no to me. They're like, "Kuo-Fong, we've been working on this, so we don't need to share more with you," something like that. I don't know how it happened. But, somehow, I just gradually do one thing after another, and I think people just got used to it. I don't know exactly how it changed. I just remember I did the tomography, and people say, "Kuo-Fong, your answer is wrong." I was like, "What do you mean by 'wrong'?" Then people would come in the outside, and say, "Oh, Kuo-Fong, I heard someone say your result was incorrect." I'd say, "What do you mean by 'incorrect'? Show me what part is incorrect." Then, gradually, bringing this conversation, and then to break through these kind of questions or doubt about what I've been doing. Then it goes smoothly as it goes. I think this thing at the beginning, people are cautious maybe.

ZIERLER: Kuo-Fong, tell me about how you got involved in learning more about earthquake physics through deep scientific drilling.

MA: My PhD thesis is, as I mentioned, tsunami and broadband waveform. It's nothing to do with drilling and so on. But the 1999 Chi-Chi earthquake was a very big impact to me. I was out in the field and, I have to say, my kids were so little at that time. When the big earthquake struck, I was at home. I was on the sixth floor. In the beginning, as I mentioned, we got earthquakes all the time, so it just shakes and then finish but that one's not. That one is a very, very long time, and then, of course, the kids are terrified. I also didn't know what to do. The second day, at that time, I was like, "I'm a seismologist, and this big earthquake came, and I don't know what to do. What am I doing?" The second day, we went to the school. We went to school and then, of course, a lot of professors are all out in the field, and we learned more and more. I was so sad to learn how many lives were lost during this earthquake. Then I was like, "But I'm a seismologist, so what am I doing, and what can I do better?" To skip all this emotional part, when we go to the field, there's a large slip. Then, I still remember, I was in the front of a very large, like, ten meters of uplifting. I was standing there like, now, I know earthquake plate tectonics. Plate tectonics is not just a question in a book. It's not just the exam I took in the class, because that's always the exam question: what is plate tectonics? It's real. The Earth is moving. It's moving this much in a few seconds. I was so shocked. It's like what I learned in the book is real. It's not just in the book. The second thing is why? What kind of mechanism can move this much? What's the reason? I began to go to earthquake physics to understand what's the reason to have this big movement, and also why does the building damage? That's how I moved myself from earthquake physics also to earthquake engineering, because I wanted to be also more practical to really bring in our knowledge to people.

ZIERLER: Kuo-Fong, tell me about developing a seismic network in Taiwan, and your role in that.

MA: I didn't really have a role in that, actually. [laugh] I'm just a user. The network is basically operated by the Central Weather Bureau. We have a very good colleague in government agent. They operate this network. I don't need to do anything on that. They did a good job for that, quality control, and so on. The other network is by IES, the institute I'm in, Academia Sinica, for the broadband waveform and broadband instruments in Taiwan. We call it BATS, B-A-T-S, Broadband Array in Taiwan for Seismology. That was also operated by another colleague in IES. Very luckily, it's like FTP, the data, and analyze the data. [laugh] I don't really maintain the network. But for the drilling, I put a borehole seismometer in. That's how I do that. For a certain topic, I put a borehole seismometer crossing the fault, like, after the drilling. The drilling is also interesting. Of course, the drilling actually is how I can have a good international collaboration, and also how I work with Emily Brodsky closely, and that's how all this together, like, Europe, Japan, US, for the drilling. It's because we never drill, and I'm not a geologist. I've never seen the rock before so [laugh], when earlier they say, "Oh, Kuo-Fong, you are the PI for TCDP," I often say, "Yeah, that was a joke. I don't really go to the field." But, somehow, I just feel that's a very important topic we have to work on. I think that's also important for international. It's just not for Taiwan. It's also for international, to learn how a large slip was produced during an earthquake, so we have to do it. But I never drill. I never see the core. [laugh] before. I think I'm just lucky to be supported by all the people that agree with me, "This is an important topic. Let's work on that."

Understanding the Devastating 1999 Earthquake

ZIERLER: Tell me why the drilling project in 1999 for TCDP, why was it so successful, and why then did it attract such international attention?

MA: I think drilling, at that time, Japan was doing pretty much, like, for 1995 Kobe earthquake. But Kobe earthquake was a strike-slip fault. That means you have to drill a hole to a neighbor, and then have the side track to heat the fault. But for the Chi-Chi earthquake is the shallow dipping 30-degree, and also we have a very large slip at the surface. We are able to really access the fault zone to a somehow manageable budget. That's how the Chi-Chi earthquake, that we can just have the vertical hole, and then keep the fault which has a very large slip. As I mentioned, it's about 10 meters. That becomes the only one in the world still, actually, so far, the clear evidence to show this is a fresh slip zone right after the earthquake. From that, we are able to measure the grain size, the chemical and physical process, and also to understand the frictional coefficient is so low. It's much lower than the number we had before, like .6 for the Byerlee's law. But the friction in a large slip, it can be less than .1. That's why it's important, and because that's direct evidence to bring some hypothesis.

ZIERLER: Kuo-Fong, tell me about the role of this research and what it taught us about fault zone dynamics.

MA: As I mentioned, we talk about this 10-meter slip, the large slip. The reason is for the core, we see there's some fluid involved during this slipping. Once the fault really ruptured very fast, the fault might be widened, and the fluid coming in to lubricate the fault. When we retrieved the core, we can show that as evidence to see that's the process for the thermodynamics. Also, from the chemical, even though I told you I don't like chemistry—

ZIERLER: [laugh]

MA: —I dislike geochemistry. But, at that time, I began to learn geochemistry, about this illite, this clay, the smectite, composition of clay to give the indicator about how much heat was generated during faulting. Then I was like, oh, that's how geochemists were doing. Then I began recall the mineralogy, petrology I learned in undergraduate, and pull those together into my interpretation of my waveform simulation. As I mentioned to you, I also only look at the seismic waveform. The seismic waveform near the drill site showed a very long period of motion, and we don't know what's the reason to give this long period, until we get the core because the thermodynamics precision lubricate the fault to give this long period of motion. Now, the engineers began to be aware how this long period of motion impacted the buildings in the neighborhood.

ZIERLER: Kuo-Fong, tell me about your research on the connections between fault zones and natural hydraulic fracturing.

MA: As I mentioned, after drilling, we put the borehole seismometer in. At that time, again, I talked to my students. I said, "I think in South Africa, South Africa has this minimum magnitude. What's the minimum magnitude we can detect? How small is small?" I talked to my students. "Let's bet. How small is small? Let's see how much we can do from the borehole seismometer." But, at the same time, I also say, well, and then, I think, observation for one year, we don't really see the earthquake nearby. We find out this complete stretch that we don't have any earthquake on the fault actually. I talked to my students, say, for actually doing a lot or say for the night it began, but somehow there's a lot of borehole seismometer study in Southern California. South Africa also have a lot of the minimum magnitude. I told my students we couldn't beat the minimum magnitude because we don't have an earthquake nearby. But we still have to do something unique. I say I don't want to repeat anyone they have been observing. I want to see something they don't see, because we are in the fault zone, which just lifted for 10 meters, and we put a borehole seismometer in. We're supposed to see something people don't see it. If there's anything people have seen it, let's drop it. I want to focus to something people don't see.

My poor students [laugh] and PhD students, we looked at it one-by-one to see. We just focus on even nearby what's small enough but unique. We category a different group, and I saw this important observation only with P-wave without S-wave. We're like, "Is that real or is that an instrumentation problem?" If that's an instrumentation problem, then of course that's artificial, so I have to prove that's real—so all this process. Then going to AGU, of course, a lot of colleagues would criticize it. "Kuo-Fong, no, no, there's an S-wave there. I think there's something you missed. Maybe what you're seeing is S-wave, P-wave, some way just appear." Through AGU, I'm able to somehow justify my observations. Whenever they give the question, I would say, "No, no, I already checked. This is the answer." But if there was some question, it's something I did not think about, I'd say, "OK, that's very good. Let me do that." In the end, we proved this isotopic event might be due to this natural hydraulic because the fluid migration, because the fault zone is so impermeable, the fluid might be trapped beneath the fault zone, and then give this natural phenomena. Later on, for this shale, gas shale, they see a lot of related features but what we observe is the nature events. That's how it happened, and I'm glad we are able to do something unique. [laugh]

ZIERLER: Kuo-Fong, what were the implications of this research on our understanding of some of the seismological concerns relating to fracking for energy reserves?

MA: For the energy issue, I keep saying it shows actually for the borehole seismometer, you are able to detect the very small events. That's important for, also, now the news is—that's the news maybe five or six years ago—it's because of this fracking issue. People are terrified, and then all this geothermal exploration project has to shut down. Somehow, I feel like, if you have a borehole seismometer, you are able to really have a good detection. You can give this green light or red light about maybe the induced seismicity might give some impact, or it's not something you have to worry. That's one thing. But to come back to the observation itself, I think that somehow can give to understand the healing process of the fault. My hypothesis for the isotropic event was, the reason for that is the fluid was capped. But, at the same time, because we had this near complete stress map, the stress is somehow equivalent. But the plate motion might still bring in the stress on the fault. Eventually, this isotropic event might disappear. This is something I need to catch up now for the study to see whether this isotropic event decays with time. But, at the same time, we also don't know how long the fault will heal. The earthquake of this type happens for maybe every 300 years. Ten years or twenty years are not long enough, but still whether we are able to see the recovery of the stress from this kind of observation, and that's something I feel is important to do.

ZIERLER: Kuo-Fong, a somewhat technical question relating to more recent work. First, what is the threshold of a micro-earthquake? How small does it have to be to be a micro-earthquake? Then what is the value of studying micro-earthquakes in order to understand earthquake nucleation?

MA: I think we don't have a clear definition for micro-earthquakes but I think maybe in general, less than magnitude 2, because that's somehow the network is almost the stress fault for the network to detect. For example, as I mentioned, at Central Weather Bureau, we have, which is complete magnitude, which is 2 or 1.5. Micro-earthquake might define as this value, less than 1.5 or 2. But if you go to even smaller, we actually go to -1 or -2. I think -1.5 is somehow the extreme we can get now. As I mentioned, South Africa mining, that's for mining, I think they are -4. But we still don't know how small can be small.

ZIERLER: No, please.

MA: I just forget you have one more question I would like to answer now is about why do we want—

ZIERLER: Earthquake nucleation, yes.

MA: Why do we want to understand micro-earthquakes? Because it's the nucleation mode. But that's why we want to have a borehole or this MiDAS project, I was saying, is the nucleation actually in the beginning is maybe microseconds. But microseconds is very easily attenuated if you have a station at the surface. If you have observation at the surface, those waveforms are already contaminated due to the heat or due to the medium attenuation. If you can be as close as possible to the micro-events, then you are able to capture this microseconds nucleation phase, and then we can see how large the energy was released, and how much stress was needed, maybe we can resolve this mystery about earthquake nucleation, and also how is that related to fluid maybe. Some fluid migration might also generate those micro-earthquakes.

ZIERLER: Kuo-Fong, what were some of the key discoveries in your research relating to dynamic stress propagating from remote earthquakes?

MA: That part I didn't really involve that much. I think Emily did a lot for the dynamic triggering from the remote earthquake. I think in Taiwan, for example, with the Hengchun earthquake 2006, we could see some groundwater level changes. Those things were detected but still not really well explained. I think it's more like phenomena. That's actually for the MiDAS project, as I mentioned, I have this exciting project. I places boreholes optical fiber but, at the same time, I have another hole to measure the fluid and also temperature changes and the pressure changes. I want to see whether I can actually capture these phenomena at one site, and then it may be possible to give some physical insight of this behavior. But for the trigger things. I think groundwater was clear, but I didn't really go to that field that much.

ZIERLER: Tell me about the origins of the Taiwan Earthquake Model, and how you envisioned it becoming part of the Global Earthquake Model.

MA: The beginning of the Taiwan Earthquake Model is actually invited by Ross Stein. He was at USGS at that time. I don't know whether you know Ross Stein. He actually was the foundation for the Global Earthquake Model, and he came to Taiwan. At that time, he was at USGS, so I knew him when I visited USGS. Then he mentioned about this idea for the Global Earthquake Model. Also, that's about also the time when I started the TCDP. The earthquake was in 1999, but the drilling started in 2006, 2005. I finished the drilling about 2015, and I talked to myself. What am I going to do for the next 10 years? What's my target for the next 10 years? For the TCDP, I do the 10 years for the science topic. But what am I going to do? What is the next for me? Also, at that time, Hiroo Kanamori, again, my supervisor, he came to Taiwan very often. I actually invite him over several times. He told me, "Kuo-Fong, if you want to study earthquakes, you have to talk to engineers because engineers are the one who can provide solutions. Scientists just find the problem, so you have to talk to engineers." Before 2015, I don't talk to engineers that much because I was working on drilling and so on. Then I was like, yes, maybe I should put myself—not just for the science but, at the same time, to engineers.

Then Ross Stein's invitation just came about the right time. He said like, "Kuo-Fong, for Global Earthquake Model, you want to bring the geology engineer and government agency to have the solution. We have the science, we have the engineer, and then the policy." That's how we can bring things together. Also, at that time, I was also mature enough. I'm able to talk to our minister directly. If I was still a junior, I think I don't have a position to really talk to the minister. But, by that time, I think I was also mature enough. I was the director, so I made an appointment to our ministry of science and technology, and I talked to him. I was saying, like, "I think the earthquake, as I mentioned, is something we cannot avoid in Taiwan. But, also, for our science study in Taiwan, it's about enough—no, I shouldn't say "enough"—it's about time to put the things together, and then deliver to engineers." Also, engineers, also, at that time, they often come to me, saying like, "Kuo-Fong, I don't know how can I do with any result from the scientists, because everyone gives me a different answer. If I ask you, you give me the answer as about, as what I say, this fault maybe magnitude 6. But if I go to the other one, maybe Dr. Lee will say this fault actually only generated magnitude 5. I don't know how I can follow." Then for engineers, in practice, they couldn't have something they couldn't have the specific answer. Come to that, and then the Taiwan Earthquake Model, I think, it's about time that we have this important platform to put the science together, and then to have one window to engineers. If they request for some question, we can have some answer to them. That answer is optimum. I keep saying it's not. We don't have a perfect answer but, somehow, that's the best answer we can give at this moment. That's how we built this Taiwan Earthquake Model. It's to somehow provide this platform to put this earthquake-related knowledge in one table, and then we update this knowledge once every five years. What I mean by "update this knowledge" is by publication. Basically, it has to be in publication, and then put it together.

Models and Mitigation

ZIERLER: Kuo-Fong, what have been some of the primary values of the Taiwan Earthquake Model to Taiwanese industry, planning where industrial parks are going to be located, and mitigating damage from earthquakes?

MA: I realize we have no power of doing that. Usually, they already decide where they want to be. I often feel like, "Why do you have this plant right next to the fault?"

ZIERLER: [laugh]

MA: They say, "We don't know there's a fault." [laugh] But there's a lot of factors. It's a lot of factors, and the fault may be just one of them. Usually, they already have the location. What the Taiwan Earthquake Model does is you already have your location and let me calculate how much risk you might face. They're actually fine. They're actually saying like, "Let me get prepared to update this facility or through earthquake insurance." Actually, insurance after earthquake, after I have this Taiwan Earthquake Model, I realize how much value through this earthquake insurance for the industry partners as well.

ZIERLER: Beyond the Global Earthquake Model, does the Taiwan Earthquake Model fit into a more regional conglomeration in Eastern Asia and the Pacific Rim?

MA: Yes, thank you for bringing those up. We work closely with Japan, of course. Now, we just, again, have this project to work on the Ryuku subduction zones from Japan, all the way to Taiwan. We have a Taiwan-Japan annual meeting for 10 years. But then New Zealand joined in 2016, so now we have a trilateral, Taiwan, Japan, New Zealand, once every year. This year will be in Taiwan. Next year will be in New Zealand. Also, the earthquake comes also once every year. It's like we had an earthquake in 2016, and it is the Kumamoto earthquake in Japan, and then the Kaikōura earthquake in New Zealand. I said, "Oh, it's a circle, so Taiwan may be the next. We have to get prepared." But, anyhow, beyond the Global Earthquake Model, we also have this regional collaboration. Korea actually also wants to join, but Korea doesn't really have the high seismic hazard. It's just one earthquake maybe 10 years ago that bring then the big impact. At that time, people also argued those may be the trigger events.

But, somehow, Koreans sometimes join as a guest rather than for us it's for sure that we are trilateral because of Kobe. It's been in Taiwan for a couple of times, and my colleagues say, "We have to have this meeting this year because I don't want to be in Taiwan. We have to go to New Zealand." [laugh] We are going to have this meeting in Taiwan in October, and then hopefully next year in New Zealand. To come back to the Global Earthquake Model, for Taiwan to join the Global Earthquake Model, it's also very challenging. It's because of China. We are able to join using the Taiwan Earthquake Model. I have to thank Ross Stein. In the beginning, everyone is using the national flag by their country. But Taiwan is not allowed to use our national flag as a member, and that's why we named ourselves Taiwan Earthquake Model to make Taiwan visible because we could not use our national flag. Then Mainland China was not happy with our membership. But we are able to join because China was not a member. China doesn't want to expose their data to the public because for the Global Earthquake Model, you have to make yourself visible, transparent, and China doesn't want to be that transparent, so they never joined. That's how we can join as well. At that same time, also we can make our results or our study more international. That's also important for our government to know us. It's because we're an international member, and we can talk to the government about what we have done here with this National Hazard Map is up to date, is a state-of-the art study because that's internationally recognized, and it's somehow comparable to the international level. That's also how we are able to convince our government and even the policymaking. That's very helpful to have this international membership.

ZIERLER: Kuo-Fong, as we move our conversation closer to the present, I wonder if you can take about some of the value you have derived from very old seismograms, things that are almost artifacts at this point.

MA: As I mentioned, I was so lucky that the late '90s became digital. I was like it's only four, we're working on analog data, because I was working on the 1989 Pasadena earthquake, the 1992 Landers. It's all digital. I saw some people digitizing all this analog data. I was like, "What a fool. Why do you want to waste the time doing that?" But then here, I become more mature in seismology. I realized how important those analog data is because an earthquake comes once every 100 years. All these big earthquakes, the record was very precious. I began to study the 1906 Mason earthquake, and that earthquake was very important. It's because it's 1906. It's a magnitude 7 event, but the surface rupture is so short, only like 15 kilometers. People don't understand why. When we look at the waveform, actually, I went to Tokyo. I went to Tokyo University to get the data because Taiwan, at that time, was a colony of Japan. The important data is always missing because everyone is taking the data away, and never returns the data. We couldn't identify those records in Taiwan. Here, I go to Tokyo University, and then, as I mentioned, Kenji Satake was in ERI, in charge of this archive. Then he said, "Kuo-Fong, this is the whole section for Taiwan. You go for it."

Then I dig this out and analyze the record, and I realize the driving force is underneath. It's not the surface one. The surface one is the one light your eyes. But the real driving force is underground, and the surface one is just a sidetrack. That is important for our Taiwan Earthquake Model. It's a fault system. It's not just the one you saw at the surface. It's the whole fault system. Then I began to study 1916, another earthquake in the Central Weather Bureau under the center range, and 1920 magnitude 8 earthquake. Because of the Taiwan Earthquake Model, I help to understand what's an earthquake hazard, and then I understand how precious those historical records are, and I put myself into that. At the same time, I also feel if you are a junior scientist, it's difficult to put your career into those topics because you don't know whether you can get any answer out, or whether you can have any publication if you want to get promoted or get a tenure position, because of the risk. You might put a lot of effort, but nothing comes out because of a lot of uncertainties. I also studied the 1604 Quanzhou earthquake in China. That's a magnitude 8 earthquake, but it's not from a subduction zone. It's like a historian, and I enjoy doing it. But it's something you put in, you don't know whether you can have an answer.

ZIERLER: Kuo-Fong, at the beginning of our talk, we discussed some of your current activities. Now that we've worked right up to the present, for the last part of our discussion, a few retrospective questions about your career, and then we'll end looking to the future. First, if you can think back to your time at the Seismo Lab, what did you learn there about collaboration, about how to do the science that stayed with you, that's informed your research ever since?

MA: I have to say all my "nutrition" in my career comes from Caltech, especially my classmates. They are all these nice professors or scientists. I learned from them, and I still have all this dialog with them. If I have key questions, I can always go to them, and then we always have this good discussion. I send my students to them, so somehow it becomes like more and more involvement just after me. We have so many of my students or some other colleagues that went to Caltech also, either just for a visiting program or for a postdoc and for a PhD and so on. Also, Emily Brodsky, actually, she is much younger than me. She actually entered Caltech. I already get my degree. But because I visit Caltech almost once every year at that time, I saw Emily in class in the Seismo Lab coffee hour. I still see all these Caltech students, and we keep having this conversation. I feel all my career has come from what I have learned from the Seismo Lab and also later on for any connection because of Caltech. In the beginning of my career, I also feel like if I go to an AGU meeting, they say, "Oh, this is Kuo-Fong from Taiwan." People don't care what Taiwan is for. But they said, "Oh, she was from Caltech," and then people were, like, you see the change in the eyes. They will say, "Oh, she was a student of Kanamori." They're, "Oh," then they begin a conversation.

ZIERLER: [laugh]

MA: Then maybe like 10 years were like that. I was like, yeah, people talk to me only because I was from Caltech. But then later, I'm glad people now talk to me. Maybe still I was from Caltech, but they also recognized me as my work in Taiwan, and I think that's something that's fortunate to realize that.

ZIERLER: Kuo-Fong, if you could look back to your time as a graduate student to now, what were some of the big mysteries in the field that have been resolved, and what remains an open question?

MA: I think the important results probably is the—how do you call it? How am I going to say it? Maybe there's a big distribution on the fault? How much fault was slipped during the earthquake by seismogram? I feel that's a genius way. Whenever an earthquake comes, now it's almost routine. Like, we know how big this earthquake is, and how much energy was released, and how much the fault was slipped. But something we're still not yet to resolve, as we discussed, is how the fault was nucleated; how the Earth was nucleated; how the fault was ended; and how long does it take to heal the fault; how much the stress can recover from this one to the next one. Even though now we have the rate-state simulation to generate the synthetic earthquakes, but I still feel this architecture, the fault architecture was not yet to be implemented well to really have a better number to predict the behavior of the fault. That's something we might have to work on more.

ZIERLER: Kuo-Fong, for all of the research and all of the collaborations that you've been involved in, what are you most proud of, and where do you see you've made the greatest impact?

MA: Again, I always recall the time when I got my PhD degree, I had that also, and I talked to myself. I was like there's so many geniuses in the world—not to mention what I had already seen in Caltech. Nothing would change without me as a seismologist. As a seismologist, it means nothing to the world as a Kuo-Fong because there are so many geniuses, I couldn't contribute more. But then now after all these years, I feel like I'm glad I might contribute something to Taiwan to have this impact to change the policy, to bring in the science to, as I mentioned, this borehole seismometer, the drilling, and then also have the special attention for the international community to see what Taiwan has been doing. When the Chi-Chi earthquake occurred, I was thinking as I want to have an important publication because I don't want to feel Taiwan is just the one that suffered the large earthquake. I want to show Taiwan has a seismologist which can contribute something to the world. That's just something that came out in my mind when, as I mentioned, I was like shocked by that, and also all these casualties. I feel that's something we have to do something also for the people to save their lives. I'm glad I might come to something like that in a certain way, and that's something I feel grateful.

ZIERLER: Finally, Kuo-Fong, looking to the future, for all that you've accomplished, what remains to be done? What's most important and interesting to you for as long as you want to be active in the field?

MA: I think something I want to carry on is, again, the ground motion to the buildings. How can we contribute to the knowledge to reduce the impact from the large earthquake in reality? Obviously, engineer, they always say, "I can just build a better building." But what do you mean by "better"? I want to make this become a number, just to give the index. Then for Taiwan, it's also, actually, for my age now, I try not to do too much [laugh] to actually do this. They should do that. At the same time, I also feel like there's a new generation. They might be able to contribute more. My role now becomes just to have a good transition. At the same time, I also would like to bring somehow—how can I say it? Maybe to lead, breaking in some direction that people can bring in but also to be recognized. Maybe it's a simple way to say so but, I don't know, I didn't answer this question well. [laugh]

ZIERLER: [laugh] You'll always be open to interesting research, though. That's for sure.

MA: Yeah, I couldn't stop myself. Whenever I say, "Oh, no, I don't think I should do that"—

ZIERLER: [laugh]

MA: —I say, "Kuo-Fong, I don't believe you." I couldn't stop myself either. At that same time, I'm like, yeah, actually, now doing science is so important and so fun. I was busy, but I enjoy to be busy. But, of course, I can also decide what to do, what to be busy or not too busy. [Laugh] But, somehow, I think it's still interesting to carry on this study.

ZIERLER: Kuo-Fong, on that note, it's been a great pleasure spending this time with you. I'm so glad we were able to capture your perspective. Thank you so much.

MA: Thank you so much and thank you for all these key questions.

[END]