Masako Tominaga

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This transcript is based on a video-recorded interview deposited at MarE3, JAMSTEC (Yokosuka, Japan).

The transcripts of the research project Oral Histories of Scientific Ocean Drilling are polished representations of oral conversations, and are intended solely for the purpose of preserving and documenting personal accounts and memories. They are not a literary product, and are not intended to exhibit literary qualities.

The primary goal of this transcript is to capture the spoken words and memories of the interviewee as accurately as possible. Minor editing and polishing works have been performed to enhance clarity and readability while maintaining the authenticity of spoken discourse, including non-standard grammar, inconsistencies, repetitions, and pauses.

The reader must be aware that memories of an event can vary between individuals and may evolve over time due to various factors, such as subsequent experiences, interactions with others, and personal emotions.

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Please cite the interview as:

Interview of Masako Tominaga by Beatriz Martinez-Rius on 2025 December 17, Ernest N. Morial Convention Center (New Orleans, USA). [link]

Beatriz Martinez-Rius (BMR): Today is December 18th of 2025. I am Beatriz Martinez-Rius, historian of science at JAMSTEC, and I am at the Ernest N. Morial Convention Center of New Orleans, during AGU 2025, with Masako Tominaga. Thank you so much.

Masako Tominaga (MT): Thank you.

BMR: Can you please first of all introduce yourself, saying your name, affiliation and position?

MT: My name is Masako Tominaga. I am Japanese. I am a tenured associate scientist at the Department of Geology and Geophysics at Woods Hole Oceanographic Institution, in the US.

BMR: How would you describe your research interests?

MT: My research interest is to understand the process and architecture below the seafloor that host chemical, biological, physical, and geological phenomena. So, understanding the interface between the so-called solid Earth and oceans.

BMR: What is your scientific background?

MT: I call myself marine geophysicist. I use math and physics to describe these phenomena. And nowadays we can use a lot of sensors, physical sensors, acoustic, also magnetic and chemical sensors, to put all the puzzle pieces together by conducting so-called remote sensing using underwater robots. That’s what I do.

BMR: I will ask you more or less chronologically. And I’m sure this work will come up along the way.

MT: Sure, okay.

BMR: First, I’d like to ask you about your background. Where did you grow up? How was your childhood like, and what did your parents do for a living?

MT: I grew up in a very socio-economically ordinary family: it was my parents, and I have a younger brother, five years younger than me. My father, due to his job, so-called a salaryman in Japan and pretty successful one, he had to move a lot for the promotion. So, I moved probably 6 or 7 times until finally they settle in Kamakura. That was when I was eight. After that, my father became tanshinfunin [note: having a job away from the family], the single person, having company apartment somewhere and living away from family. So, my mother had to stay home, being the mother and then holding the entire fort for us. She almost single-handedly raised my brother and myself, but whenever my dad came home, we had a lot of fun together.

BMR: Were you interested in science, during your early childhood?

MT: No, I don’t think so. I was a very curious but lazy child. I loved reading, I loved exploration, so first dream job was archeologist. I want to go to the jungle and explore something. One day my mother told me, “Well, but you don’t like insects”. Oh. Wrong profession (laughs). Something like that. I don’t think science never came to me until really later in the school years, but I was curious, and I really like thinking… That kind of a child.

BMR: How this interest developed? Especially in Earth or ocean sciences.

MT: I think in the Japanese education system, at some point we were semi-forced to choose which direction of professions, in the very big picture: science, engineering or humanity. And I think most of my logic was driven by reading and thinking, I should stay as my personal interest. So, okay, science-engineering makes sense. But I had to study a lot to recover from my lazy years not studying much (laughs). Going to college and then, which department I have to take exam to enter? So, I had to narrow down. I’m not a laboratory person, per se. I wanted to be outside once for a while. I wanted to think. I wanted to use math and physics to explain what we observe. So, I think the moment I remember was in the high school library, there was a book written by one of the University of Tokyo’s professors about methane hydrates, using the scientific ocean drilling. And I thought, “This sounds interesting”. I think that’s how I realized there is a such a thing as Earth science.

BMR: It’s interesting that it was through ocean drilling already, right? I guess it has this component of exploration, you were mentioning going to the jungle and discovering something.

MT: Sure, exactly. Yeah.

BMR: And how came, that you moved to the US?

MT: Ah. That is also kind of evolving thing. I mentioned that my father was a pretty successful salaryman in Japan, and fortunately his profession, which the most fun term we can use is a Braumeister. He’s a fermentation engineer, so his career is about making beer at industry scale, contributing to the wine imports, and making Yamazaki whiskey. Dream job, I think (laughs). I think his generation coincided with when the Japanese economy grew so much, so every year he had to go to Europe or America to participate in this type of conventions for the beer making, etcetera; deciding which machine to buy for this new factory… Difficult! And then, throughout that experience, my father was pretty cognizant about, the world is not only here in Japan.

So, he tried to liberate that thoughts both in my brother and in my head since when we were kids: Where would you like to go? Where do you think you fit the best? This is not the only place you have to be. It’s a very atypical parenting, in that sense. So, when I go through the higher education – college years – I had to make a decision: “Do I want to wear that navy color suits, white shirt, high heels, go to those interview series, to aim April 1st after my senior year, to join which companies, if I could?”. And then I could not envision any of that. It was very stressful to me, to think that will be my future. And so, started remembering, “My father said I could go anywhere”.

That’s when I started studying, “Okay, at least I would like to study more, to earn some more thinking time and skills in life, and seems like communicating in English will become useful anyways. So, why not?” That’s how I decided it, and applied I think 12 schools in the US.

BMR: You were young when you moved to the US.

MT: I came here in 2002, so that was after my Bachelor, the Master’s degree first.

BMR: What did you study in the US?

MT: Oceanography, geological oceanography. This was a little bit lucky part of me, that one of the applications went to Texas A&M, Department of Oceanography. A&M is, as you know, the headquarter of US Science Ocean Drilling. A professor there, William Sager, saw my portofolio, “She may be useful for my research projects”, So he picked me up from the applicants’ pool and since then, yeah, I had been physically close to the Ocean Drilling Program.

BMR: Was there someone specifically influential in your approach to research, or in your future career, or research opportunities you had at that time?

MT: The people who are in my earlier years or already kind of in the master’s graduate school?

BMR: You can tell me about whatever you prefer.

MT: Of course, my parents were the most influential. Important note here is that they were the people who are not afraid of encountering and dealing with “unknowns”. They think understanding unknowns when they encounter is – unless somebody got hurt – it’s positive encountering and enjoyable. So, that whole kind of life attitude is really helpful, and probably shaped who I am and my decision making, a lot.

I was very, very fortunate to meet my career mentor. Also, I like to call him as my best friend in science, Doctor Maurice Tivey of Woods Hole Oceanographic Institution. He retired two summers ago. He was the chief scientist of my very first cruise on a research vessel. That was three months after I arrived in the US. I barely spoke English. But how he operates, how he interacts with his people,  basically became my foundation of the professionalism.

And throughout the ocean drilling program, Nobu [Eguchi]-san. This Japanese scientist, … I don’t know how much I owe him. I would say that [they are] not only exceptionally supportive of other scientists. It’s incredible that, even in the interesting professional landscape within the hierarchy that our culture holds, they never expressed any bias towards me, even when I was like 23 or 24 years old ”Nobody”. They really treated me with the respect and that has never been changed.

Two more people important to be on the record. Javier Escartin and Catherine Mevel – you interviewed her, right? Those two were also my both personal friends and career-long mentors. They never had any preconceived notion regarding rank, background, etc. For some reason, they really… Fully communicated with me, listened to what I wanted to express, exchanged ideas; and over time, it’s been invaluable how much they showed me their professional career evolves, and how their decision making could be challenging, and how personal lives never get easier. And sharing that with me. That fact itself has been tremendous and, you know, I always, when I need to kind of recalibration of my decision making and operations baseline, I usually go to all these people and talk to them (laughs).

BMR: Before asking about your first IODP expedition, I’m curious to know how did you make the connection with the people at JAMSTEC (Japan)?

MT: I was looking for an opportunity to sail on an IODP expedition when I was a student. And back in early 2000s, the program was very kind of… It was a little bit different from the program until last year, for example. And because it was a beginning phase of IODP, Mission-Specific Platforms, Chikyu, and the JOIDES Resolution running around, operating science… So, the competition-to-sail was pretty severe. It was the beginning of the US-IODP encouraging early career scientists, but I do not recall – this is only my personal memory basis – I do not recall I was called early career scientist yet, back then. The term was not populated. I tried twice for different expeditions. Never got on any. So, I talked to my advisor and he knew that sometimes in the Japanese science community, finding eight scientists to sail might be challenging. And, “You’re from Japan. Maybe you might get a chance through their system”.

He wrote to somebody, but not persons in JAMSTEC, and that somebody connected – “Maybe you should talk to this person in JAMSTEC”, and that was Sanny Saito-san. From there on, Sanny-san, Abe Natsu-san, and I think Nobu-san was IODP-MI Sapporo – Gradually we met in person, introduced ourselves and then gradually started connecting. They helped me to get to know other scientists and then, luckily, my parents’ house is in Kamakura, so whenever I go home, I could spend some time in their office in Yokosuka [JAMSTEC Headquarters].

BMR: And why a geophysicist would like to go on scientific ocean drilling expeditions with so much willingness?

MT: Geophysics is the field where we use the technique so-called remote sensing. For example, you send the acoustic signal, receiving the return, and process that data to present as an imagery. It’s like a CT scan, for example, of the Earth. But that’s not a real image. After started understanding how geophysical signal are simply response of what’s present under the seafloor, I wanted to know what are the source of these signals. Because when you look at the mountain, it looks complicated system of air; it’s never been this one plain layer. It’s layers of things. So, to me, really, learning the physical sample, hand specimen samples from ocean drilling, opened a lot of different scientific thinking, both appreciation and then also humbly limitation of geophysics itself. And learned different roles in the construction of science itself. That’s why I keep sailing to target rocks from oceanic lithosphere, so that in addressing fundamental science questions of my interest in a certain location on Earth, I can combine what I’m good at from the geophysics with samples, so called “ground truths”, to connect these two scales measurements together.

BMR: What was your first IODP expedition? And I also like to know what surprised you about it, because you have already been onboard oceanographic research vessels before that.

MT: The difference would be… I had a really nice analogy in my head. Not sure this works, but I’ll try. Research cruises in oceanography can be ad hoc. Even if it’s a part of 5 or 10-year big program, each research cruises can be a very intense project, and independent from any other research expeditions within that program during execution. So, in my head right now, just a visual, it’s like a whitewater ride. You put yourself in the river kayak and do this impactful ride once to make a significant contribute to advancing science. You’re in the middle of this river of science program, but the ride ends. But ocean drilling program expeditions are something very different in a way that, like you said 50 years program, you immediately become a part of this really big flow of people effort to carry the science objectives advancing each different sectors of a wholesale science frontier as a collective force. That’s a very different image I always have between those “typical” research expeditions and IODP. Both approaches are important and imperative in ocean science.

So, with that notion, it was intimidating when I participated for the first time.

BMR: In the sense that, your previous expeditions maybe were smaller, and you’ve met the people before…?

MT: I think it’s more… Less programmatic.

BMR: Oh, you mean like… less protocolized (than IODP).

MT: Yeah, exactly. With the best positive side: can be highly adaptive.

BMR: So, in scientific ocean drilling there’s a protocol and a process that all follow.

MT: Yeah. And that’s an important precedent the IODP set for the community. I do believe the IODP protocol was already there before any open data policy, fair, etcetera that now we all would like to adhere, it was not there in the usual research expeditions until really recently, maybe these ten years. But IODP or ODP, or even DSDP, one can access to the core and data. One can find where these cores are, how they are curated are so transparent, consistent throughout the history, and so that foundation… You used the term protocolized. That itself was very, very, pioneering. Meaning, once you sail, within a year, all the reports reveal what you did and the measurements had to be correct.

Now I do remember, from my very first expedition, I made a lot of mistakes in measurements that resulted in inconsistency of data presentation between expeditions 304 in 305. During the editorial meeting, two senior scientists from expeditions 304 fixed them all. And that itself was a lot of mentoring to me.

BMR: Were you on 304 or 305?

MT: 305. Despite the crossover – this 304 did this way to make it consistent; please do follow this protocol. I tried with my counterpart, but I do not believe we achieved that expectation. That was a huge lesson early on. And then, again, revealed the different degree of commitment that IODP expeditions require for scientists.

BMR: And what other key learnings did you take from that early involvement in scientific ocean drilling that you could later apply to your career or other areas?

MT: I think it would be more or less people management, including myself. The two months of sailing itself among international professionals is a project, and there are a lot of investment made for years before that starts, and a lot of investment afterwards as well. So, to be a part of it, part of such project… I feel I need to commit to it in a certain way that aligns with many others science priorities. And that is very different from… “I write proposal, I get funded, I become a chief scientist, and then I manage a month and a half cruise on research expeditions, then we all publish”. It’s a very, very different role. And if you put 24 scientists together from different institutions and countries, usually, there are… Different understood expectations, mannerisms, in science. Even if we do like to set a goal as the same in terms of equality, peace in spaces… Might be different to get there. And so, how to how to manage [that]? My role clarity with respect to others. That is probably one of the most important learning I have had from IODP expeditions.

BMR: I kind of see that you like having this sort of leadership position? Well, leadership is not the right word, but a position that gives you an overview, a strategic vision of an expedition, people, operations… Do you enjoy that, or am I getting it wrong?

MT: I do not have to be a lead. If the situations or landscape determined I would be the best choice to do so, I would be the lead and I would merrily do that. But I don’t have to be the lead all the time. Instead, I think it is my very much personal joy to bring about the place where people can talk and solve a problem together. And then, when even small scale, when I could connect finally these two people talk, engineer and scientist to talk, I feel like “yes we did it!”. I think it’s a very simple professional satisfaction (laughs) I always try to establish. I don’t need to be the one who has to appear to herd beasts (both laugh).

BMR: I see, I understand. What has been your involvement in scientific ocean drilling after that first expedition?

MT: I sailed six times more, and one of which I did the co-chief scientist. So, yeah, over the course of 20-some years, I had been very fortunate to sail on some of the really challenging expeditions, because I’m always interested in hard rock, which is below sediments.

BMR: all of them with the JR, as I understand?

MT: Yes.

BMR: How being a co-chief in the JR is different from being a science party member?

MT: My case might be a little bit different from those of who led science expeditions. Ours 385T was science but also engineering. And… We did not get anything (laughs). I think, in that sense, because there were no scientific products, it was really… Waiting in the co-chiefs office, and monitoring situations.

What did I observe from that expedition…? I found it interesting that, even in the professional world, how you set up yourself to your role and the others are very different. I think at our heart we were pursuing the high quality science, for sure; but how we operated appear to be very different. So, I learned a lot of myself of, “Okay, how can I respect that difference in style?”

Interestingly, the science world is a little bit different from company offices. This is how I understand it from my brother, who works in a fore-profit company. Oceanography, particularly, we have to get to know each other, even if we try to avoid confronting and facing particular persons in the end. Nobody can hide who you are. So, it is very much my lesson that, in such environment, I need to practice to tune myself, and be consistent. So, after that expedition, the 398, I became pretty good at that. I now have a lot of boundaries set around me.

BMR: It’s interesting that you compare it with a company. As you said, at sea you cannot hide who you are, which points to the social component of science at sea, living together in a confined space. If you work for a company, after 8 hours you go back home and you do whatever you want, but at sea, you are 24 hours with other people. And sometimes conditions are stressful… so you and your frustration, or joy, or boredom is something also important to handle.

MT: Right. You know, being a chief scientist on oceanographic expeditions, not IODP, I became good at managing my own neutrality or my character, I would say. And then I became pretty upfront about it to the others so that they don’t get confused. Once I set that on the day one, I just get through the entire expedition with the same degree of stability.

BMR: That consistency is important in the chief scientists, I understand. A co-chief cannot start on the upper level of excitement and then break down.

MT: No, exactly.

BMR: I’d like to move – if you want to add something about expeditions we can talk about it. But besides that, I’d like to talk about your recent role in planning the US capabilities for sub-seafloor exploration.

MT: I think… My role in an IODP expedition is, as we just discussed, can be defined pretty easily – unless I’m not the co-chief scientist. But outside of IODP community, in the United States, there is a so called UNOS community. UNOS stands for University National Oceanographic Laboratory Systems, which is a consortium of all the vessel operators, and supporting facilities, and programs, where I have worn a few hats as a manager person to shepherd programs and projects, in virtue of fully supporting oceanographic operations. So, I am a scientist, I could just get funded and sail, and do research. But that’s not how I believe oceanography research expeditions should be. Without the ship, without crew, without technical support… We can’t do anything. So, it should be acknowledged as an extremely collaborative effort, and that’s how I try to place myself in the US oceanography, as my role. So, advocate of technical capabilities, advocate of good leadership as a scientist, and break some barriers from both sides so that, again, bring about the place where people can talk to solving problems.

The seafloor sampling challenge came up right around the Covid pandemic happened. I started thinking about, “Okay, from the bottom up, how could we retain, if not implement, US oceanography to the nearest the future?” Right around the same time, we started hearing about the possible end of JOIDES Resolution. That’s when I started reaching out mid-career scientists from very different disciplines, and discussed, we probably should provide a place where not only scientists, but operators, technical staffs… Can get together to, first, realize what we have, and once we understand the current inventory of assets, we have outside of ocean drilling, of course we will realize, “Oh, JOIDES-type of capability is one of a kind. But in the interim, these are the tools scientists can creatively utilize to achieve seafloor sampling with even smaller or different scales from the JOIDES,…still something we could do”. So, that’s the workshop we put together.

During the workshop, the community has realized the current UNOS academic research fleet has lesser capability to, for example, conduct deeper coring, deeper dredge, and also over the side drill – like the Kaimei system. And we identified the reason is the A-frame, the over the side handling system on board the vessels, is not big, strong enough to manage these science needs. So, hopefully in the future improvement of the fleet, research vessels can be designed around such strong A-frame, that can achieve a different type of seafloor sampling. That’s the one of many US priorities we could identify.

BMR: I have a bunch of questions about it (laughs).

MT: Sure!

BMR: Is this effort as a national-only effort? In the sense of, are you looking for the resources to develop research within the US community? Or is there a component of international cooperation within this framework of envisioning the US capabilities?

MT: I would say that currently, the effort is under the auspices of US science community and its supporting agencies, the National Science Foundation and other US agencies. But I would like to add, international component should be always there. If there are aspects, design of assets, infrastructure… that already exist and run somewhere else.  \ Hope we could have open boundaries to continue discussing this.

BMR: I understand, having a strong community should come first and then you can move towards a more international framework. I’d like to tackle now the elephant in the room: do you think that having a scientific drillship is something necessary?

MT: Yes.

BMR: And why is it important?

MT: Two different aspects that I think it’s necessary. One, as an infrastructure. It’s simply a mechanical machine. The more you use, the better it runs. And the ship as a system really falls into this category of mechanical, electrical, infrastructure that if you do not run, it’s not oiled well, and therefore you have more problems. That was, I believe, JOIDES’ strength. And… if it becomes rental or lease, the maintenance and improvement become really ad hoc. You cannot follow up issues; it might be much difficult time to improve systems… Maybe a house is better analogy here. You live on a house, you go there every day, you open the door every day and then, “Oh! I have to fix this bulb. Oh, I should shine this hallway”. That’s how we make the big infrastructure alive. That’s the one operational necessity to own one.

Another aspect is people. Why do we like to own a house? Because you can do your gardening right outside of the backdoor, for example. You don’t have to call your landlord and, “Can I hang my picture on the wall?” Whenever you ever repair that hall perfectly, you nail on the hall, and if you have the house on your own, it could centralized your and your family’s effort very efficiently and that entice people to pursue opportunities.

With a reasonable set of infrastructure, the science program has a homebase with which we can be more adaptive and scale the programs easily. I think that those are the reasons. Sorry, it’s not a scientific, but I think it comes to human nature, really. Any business model comes with human nature.

And then, I think that we are thinking and addressing this question because we hope that there is this long-standing program and continuation of it. If this is only a five years program, I don’t think we can discuss this in the same way. But because the value of the ocean drilling program is its longevity, becoming a part of humanity and history – that you study – in science, modern science; if our premise will be to continue the program then, yes, we do need to have a dedicated vessel.

BMR: In your experience, how can scientists doing this sort of planning can better attract funding and attention? How to get support?

MT: I don’t have an answer to that… We hope that we can move things. We hope with that we have a collective power to move things upward, to attract funding supporters… But we all know that that might not be the case.

So, I don’t know how to attract people who currently have power to support science, ocean drilling science, but at least we could continue conversations without bias.

BMR: It’s a difficult question; it has no answer.

MT: It is. Did anybody else answer this question?

BMR: Every time I ask the question, the first answer is, “I don’t know how; we are trying to”. It’s so difficult because it depends not only on political priorities, but also on where they see value – on things that go beyond scientific production, like national pride, or science diplomacy… but it’s difficult to draw attention to it.

MT: I wish we have different ideas to market it, right? I wonder… I think the community believes that we are talking about science priorities and, for example, understanding the deep biosphere from the deep sea is important for x, y, and z. And to get that drilling ship is the only tool. That’s the equation we have been using.

BMR: Yeah.

MT: Is that really… The effective approach? We might have confined our thoughts, how we should be thinking, itself in a box for a long time, in part because we know that worked. But if it’s not working, then a lot of way of thinking might have to be changed.

BMR: I understand what you are saying. Some formulas have worked for some time, but at some point, you have to try something else.

MT: in the end, it is a privilege that we can do science in the manner of exploration. It is a privilege, and we feel it now, more than ever. I have a lot of thoughts for future, but (laughs). I hope people can keep talking.

BMR: May I ask you a final question? What has been the most valuable, the thing you appreciate the most from your involvement in scientific ocean drilling? Or more broadly speaking, from your involvement in seafloor exploration?

MT: Most valuable… People that I get to know, and that I dear. Yeah. People. I wish I can say like, “rocks”, but no (both laugh). Take two, action!: logging data and rock samples (both laugh).

BMR: Surprisingly or not surprisingly, I would say 90% of the interviewees say, people. When you go at sea, you realize that those personal relationships are also something that you build, and you carry on with you later on.

MT: I hope that sooner than later we could come back to the very basic idea that no matter how technologies or technological enablers become autonomous, digital, non-human – so, inorganic –all of those are human creations, and so when we stop thinking, those probably may stop thinking, too. Let’s not mistake that.

And in the similar line of thinking, I started emphasizing data science works as far as we are producing new data. That new data is also from measurements on the cores (laughs), right? And all these archival cores, these are limited resources unless replenished.

I think it’s all intertwined around this human thing in the center, and you know, it’s interesting to hear everybody says that the most precious thing is friendship through work. And then, that is amazingly depicting what’s most important to us, then. Those renowned scientists who you interview, they didn’t say “rocks”. Now I have to think about, then, “What was the scientific ocean drilling is about?” (both laugh). That is epiphany of: The science is really the production of human curiosity.

BMR: And human relations.

MT: It is. I think that might be it. I said that something started changing when this century turned, right? I think in the 20^th century we, as humans, created so many tragedies unnecessarily, and learned from that, that we need to be opened. And that pendulum swung, and seems to be becoming more inwardly, defending some science activities. And you are right that Chikyu can be so symbolic, like the space station, right?

BMR: Yes, these international relations is not something sort of aspirational or just nice to say. It really happens, and networks of people who span around the world are built during expeditions, that continue much longer after that single experience has finished.

MT: I am big fan of comparative studies, like anthropology. Understanding others don’t necessarily mean you have to accept everything, but without that, we are so easy to get lost where we stand, and soon, unknowns or uncertainties only become fear and we just start driven by that defense mechanism. That’s very sad, and… receding from the progress.

BMR: Becoming each time smaller clusters of people, ones against the others. Well, it’s been a wonderful conversation. Is there something else you’d like to add that we have not talked about?

MT: Let me check… I think my highlight is those mentors (laughs) I had to go on the record.

BMR: And it is recorded. Thank you so much, and thank you also for your time.

MT: Of course. Thank you, my pleasure.