Harue Masuda

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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 Harue Masuda by Beatriz Martinez-Rius on 2025 May 27, Makuhari Messe (Chiba, Japan). [link]

Beatriz Martinez-Rius (BMR): Today is May 27th of 2025. I am Beatriz Martinez-Rius, historian of science at JAMSTEC, and I am with Harue Masuda at Makuhari Messe, Chiba. Thank you very much.

Harue Masuda (HM): Thank you.

BMR: First thing, just for the recording. Can you tell me your name, your affiliation and your position?

HM: My name is Harue Masuda. I’m working at the Osaka Metropolitan University as a Specially Appointed Professor.

For how long have you been in this university in Osaka?

Actually, I moved to Osaka City University as an Assistant Professor in 1988, April 1988, and I’ve retired in 2022. I retired at Osaka City University but from the next day, our university unified with the Osaka Prefectural University to become the Osaka Metropolitan University. And, from that day, I became a Specially Appointed Professor at the Osaka Metropolitan University.

BMR: So, do you continue working even though you are retired?

HM: Yes, yes.

BMR: What is your field of expertise? Your research interests during your career?

HM: Generally, I’m a geochemist and my specialty is to study water-rock interactions in the oceanic and continental crust. I have done so many works in diverse fields, and some of this is in environmental geochemistry concerning groundwater contamination, anthropogenic and also natural contamination; also, the diagenetic reaction to form authigenic minerals in the oceanic sediments; and the formation of volcanism in the upper part of the oceanic plate. Most of those concern the water cycle in the geosphere.

BMR: How did you got interested in this? How you got into this field of research?

HM: When I was in the Bachelor course, I started a research work on hot springs and mineral springs that contain high salinity and CO2. Now those groundwaters are interpreted as a deep fluid, including dehydrated water from subducting slab, or some sort of the fossil  formation water. But at that time, we didn’t know the origin of those waters. So, when I selected that topic, I liked the chemistry, especially the analytical chemistry – but I was a geology student, you know?

When I started in geology, I was interested in topography. I was interested in the formation of the surface topography of the Earth, first. But when I selected my subject about the groundwater geochemistry, actually I thought I couldn’t continue to be a geologist because I was a female student, and at that time, it was really hard to do fieldwork for women alone.
So, I thought… I liked fieldwork, but I thought had to select something to do in the laboratory. I liked the chemistry, so I selected the analytical geochemistry concerning tectonics. That’s the reason why I studied geochemistry, groundwater chemistry and related tectonics.

BMR: What was the situation of this research field when you started? Was there a lot of research on it? Was there some influential professor or someone who could teach you?

HM: Yes and no, I can say, because at that time, when I started in that subject, some geochemists were studying about groundwaters and spring waters in relation to earthquake prediction. They detected some geochemical precursors related to earthquakes or tectonic movements. It was really new. Also, traditionally, so many Japanese scientists study about hot springs. They had so many analytical data of hot springs, everywhere in Japan, but actually, if you concentrate in the field… I started in the Arima and nearby areas, which is the southern part of Hyogo Prefecture and nearby. For those areas, there were not so many studies. Not so many people studied there. But I learned so many things related to that subject by professors working at different universities, especially at the universities of Tokyo and Kyoto, Kobe University, and so on.

BMR: You mentioned that it was difficult to do fieldwork being a female.

HM: Oh, yes.

BMR: Can you explain me more about this? Why it was difficult?

HM: When I was a student, geology was one of the main parts of Earth sciences. That was very different from the present situation. I was a Bachelor student at the Osaka City University, and in my department, the strongest laboratory was the Geology Section.

At that time, the geology students went to the field and stayed in the field. The field was almost all in a mountainous area, and they stayed there for more than one month – even half a year. They lived there, they wrote route maps, and drew the geological map of that area.

For that purpose, you have to go to the mountain area alone, you see? This was a very important thing. It’s not dangerous, compared with the present situation, but even though, for girls it’s not really safe to go to the mountain area without any collaborators or any friends.

And also, the [physical] strength. We had to carry so many rocks [the top of the] mountain to the foot of the mountain… Well, for me, I didn’t have such kind of toughness, to bring so many rocks (laughs), but I loved the fieldwork in the mountain area. Actually, when I was at the second and third grade of the Bachelor course, I went to a mountainous area in the Kii Peninsula. It’s a really deep mountain. I spent so many days doing fieldwork to draw the geologic map, there… But at that time, we had a camp, and we went there in a group. So, I never walked around without my colleagues. There was always someone with whom I went together. At that time, I didn’t care; but for the whole study, doing my own research, it was impossible. I thought I was impossible to continue that.

Anyway, for my bachelor thesis, as I said, I wrote about mineral spring water related to the tectonic movements, and actually for collecting groundwater I went to the field so many days – but I used a car. I run a very wide area by car. But this was different from the geological fieldwork.

BMR: Before continuing talking about after your bachelor, let me ask you a question a bit before in time. Where did you grow up and what kind of childhood did you had? What was the job of your parents?

HM: My parents owned a small factory to make iron products. I was born in Yamaguchi, but moved to Osaka just before entering the elementary school, and I grew up there. I stayed in Osaka – changing a little bit of place –until I finished the Masters course.

When I was an elementary school child, I liked the natural sciences. Probably you cannot imagine it, but it wasn’t common for girls, (laughs) to be interested in the natural sciences. At that time, the parents were a bit worried about a girl who wants to study natural sciences. At that time, most of the people couldn’t understand why a girl was interested in the natural sciences but, actually, I liked that subject very much. I had a telescope (laughs) to see the stars. I lived in the city area so I couldn’t see many stars, but anyway, I observed the planets, the moon, sometimes the sun… using the telescope. Also, I had glass wares to use for chemical analyses. I went to the drug store to buy reagents (laughs), so it was very different time from now. Even an elementary school kid, we could buy reagents, chemical reagent (laughs). So, I bought some chemical reagents and – well, it’s not real chemical analyses, but some sort of… playing. I collected river water and put some reagent to react, to observe the dissolved matter. That was sort of a kid’s game. I spent a lot of time doing such things.

After entering the middle school, I didn’t saw many of those things that much. I still liked natural science and I liked the laboratory work, during middle school and high school. I didn’t play with the kind of things I played during elementary school, but I had such kind of interest and I kept it. When I selected the field of studies for entering the university, naturally I selected the natural sciences. And, among those, why I selected Geology? I wanted to do natural sciences, but actually I preferred to do fieldwork, not laboratory work. Also, I liked natural geography. And also, the important thing: my parents wanted me to be a doctor (laughs). It was really natural, but I didn’t like it. I didn’t like the creatures (laughs), including human beings (both laugh). And I didn’t like to see blood; and I didn’t want to kill any creature. I wanted to treat inorganic matters. That was one of the reasons why I selected the Earth sciences, including rocks (laughs).

BMR: Something surprising about your childhood until you entered university is that, it looks like the environment you grew up was not really supportive for you being a scientist.

HM: Ah, yeah.

BMR: How did you keep that motivation? It sounds like kind of swimming against the current.

HM: Actually, my parents supported me to learn so many things. At that time, during my childhood, it wasn’t common for the parents to give especially girls scientific materials, like a telescope or something like this. But my parents supported me to learn as I liked. So, they gave me so many books, and many materials about that. But even though, they didn’t want me to be a scientist – they didn’t want their daughter to be a scientist, especially a natural scientist.

 So, when I entered the university, actually I fought especially with my mother. As I said, she wanted me to be a doctor (laughs), because at that time, if your daughter is very smart, being a doctor is the easiest way for a woman to get a job. At that time, it was really difficult for women, after finishing university, to get a job. Especially in companies. So, when we finished in the science department, if we wanted to keep a job, the only way was to become a teacher. When I went to graduate school, many people were against me. But it was very natural, because when a girl went to graduate school, there was just a very, very small way to survive.

BMR: And how was for you, to continue with your graduate studies?

HM: Uhm… I was just lucky, you know? Probably, I was very fortunate that my supervisors were all very, very good to me. Actually, as I said when I entered the graduate school, the motivation was – I just liked it. When I entered the graduate school, I wanted to continue studying my subject, because at the end of the bachelor’s course, we did some research work but only for a year. For me, it was not enough to finish it and to understand all the things. So, I wanted to continue to study a little bit more – not so much, actually (laughs). So, even though I understood it was very difficult to get a job after the PhD course, especially for girls, I thought I would finish until the Master’s course. And after finishing the Master’s course, I thought I would become a high school teacher. Science teacher.

But when I was at the second grade of the Master’s course, one of the professors working at Kyoto University suggested me to go and continue the research work in the doctoral course of the graduate school. I seriously considered about it, because I knew I would lose the chance to be a teacher, and it would be very, very difficult to continue in the job. But, anyway, I decided to challenge. Someone asked me – I thought it was a chance to challenge and to change my life. I decided to continue the [research] work, and to go to the later part of graduate school – the doctoral course.

It was a really complicated history about that, but anyway, I stayed at Osaka City University as a doctoral student, but I thought I couldn’t do better if I stayed there longer, so I wanted to move. Once I thought I would go to Kyoto University, where the professor who recommended me going to the doctoral course was, but I didn’t go there. I selected the professor [Hitoshi] Sakai, who was working at Okayama University. He was a really good geochemist, especially about stable isotopes, and I wanted to learn about stable isotopes. But, at that time, Okayama University didn’t have a doctoral course, only the Master’s course. So, I discussed with my supervisor at Osaka City University – he was a hydrologist – and we decided to stay at Osaka University as a graduate student and move to Okayama University to study stable isotopes.

After one year, Hitoshi Sakai, my supervisor, moved to the University of Tokyo (laughs), Ocean Research Institute, so I moved together, associating with him. I continued my graduate research work there, but I got a PhD from Osaka City University. After that, I got a JSPS fellowship for two years, and continue my research work at the Ocean Research Institute. Then, fortunately, I got a job at Osaka City University and I went back to Osaka.

I suppose all of the professors I met from my bachelor course, and supervisors who thought me during the bachelor, master and doctoral courses, all of them were really nice to me. That was a really special case at that time, because you can imagine – at that time, so many female students had sexual harassment or academic harassment. It was really usual. It was not good, but usual. But, all of my supervisors treated me like their own daughter (laughs), so I suppose I was really lucky. At that time, it was not very easy to get a job at universities, especially for women. So, I was just lucky.

BMR: How did you go from working on land, to go to the sea? Was this during your time at the Ocean Research Institute?

HM: Yes, it was.

BMR: What was your first experience at sea, and what do you remember about that?

HM: That was a cruise to Hawaii.

BMR: From Japan to Hawaii?

HM: Actually, my cruise was from Hawaii to Japan, but most of the students started the cruise from Tokyo to Hawaii and going back to Tokyo. But I flew to Hawaii and joined the cruise from there, and went back to Tokyo by ship – the Hakuho Maru.

BMR: How was it? What kind of research did you do?

HM: It was a really good experience for me. We went to Hawaii because we did a research work on hydrothermal systems at Loihi, the newest volcanic area of Hawaii islands. Of course, it was really nice cruise, and I met a young woman professor, Patty (Patricia) Fryer. Do you know her? At that time, she was an Associate Professor at the University of Hawaii, and she was a petrologist studying ocean floor rocks. She became really famous about mud volcanoes along the Mariana Trench. She was the first scientist who found out the importance of mud volcanoes there. Anyway, she was young of course, and we shared the room for two weeks. At that time, I learned so many things about science, life, women’s life as scientists… and English (laughs). 

BMR: (laughs) Of course.

HM: After that, we had so long communication. I learned so many things about science… One of the most important things is: my eyes opened to the world. So, in Japan, there were very few women scientists, especially in our field. But in the United States or in some other counties, there were many women scientists working and doing research work, even in fieldwork studies – in the real field. So, it was really impressive for me. Maybe I wanted to be such kind of women.

BMR: I see that it’s very important, to find this kind of influence.

HM: Yeah.

BMR: And from there, how did you become involved in scientific ocean drilling? Is there any relation of you being in the University of Tokyo, and your involvement in scientific ocean drilling?

HM: The first time I joined scientific ocean drilling was in 1986, just the year after the Hakuho Maru cruise from Hawaii. That was by chance (laughs). I didn’t select it. We went to the Costa Rica rift; it was the hole 504B [of ODP Leg 111]. That is a really famous hole – the deepest hole humans have drilled in the basement of the oceanic crust. I studied about submarine hydrothermal systems after finishing the PhD course, and that cruise included some of the hydrothermal activities in the oceanic crust. Actually, the most important purpose of that cruise was drilling into the mantle, but it wasn’t successful – even now. But, once they thought that it was possible…

At the cores recovered from that hole they already found changing rocks at the interaction with hydrothermal water. So, as a scientist, my supervisor Hitoshi Sakai decided to go there as co-chief scientist. And I went there with him. That was the first time. There it wasn’t successful, so the scientific results were not very nice. But it was a really good experience.

BMR: Is there something that you learned at that time, onboard the JR, that has been important during your career?

HM: I think so. Scientifically, it was not very important for me, but it widened my eyes to the world, worldwide; and also, to the science world – it’s really important. Because as I said, there were not so many women scientists in Japan at that time, specially in our field. There were very few women scientists older than me. So, we didn’t have many role models. But, on the ship, there were many women scientists, women technicians, and women students. So many women were joining the cruise. I learned – Japan is special (laughs). So, if I open my eyes to the world, my situation is not very special. I can be a common – not an unusual person. That was very important.

And the other thing it’s important – I became really good friend to [Hodaka] Kawahata-san (laughs), from there. We knew [each other] before the cruise, but we spent two months [together] and we didn’t get so many samples, there. Of course, we worked together as geochemists to analyze pore water and other things, but because we didn’t get many samples, we had much time to talk with each other. We became really good friends. Even now, it continues. It was a really good experience, to get such kind of important friend.

BMR: I think you are not the first one who mentions meeting someone in the ship, as an early career, and then continue during all the career being friends and collaborators. How your career continued after that? And how did you continue in relation to scientific ocean drilling? Did you go back to your groundwater studies?

HM: Actually, I almost returned back (laughs), because I had a really heavy seasickness. Not really nice. After that cruise, I joined many cruises by JAMSTEC ships, like the Natsushima and the Yokosuka. But, I’m really weak. I have seasickness. So, sometimes I hated to continue the study of the oceans in those cruises – not only drilling. Because in the Costa Rica rift [expedition] we couldn’t get many samples. After spending two months [onboard], when we went to Okinawa, we had a typhoon. So: I had a very heavy sea sickness and we couldn’t get samples. I couldn’t be patient for getting samples, with such kind of waste of time (laughs). And also, I got a job – after finishing the postdoc period, I went back to Osaka City University. It was a little bit difficult to continue in the ocean sciences because it was not easy to join the cruises, and because of the difficulty for obtaining samples. And also, added the difficulty to join the cruises. So, I had to study something about subaerial subjects. That’s mostly the reason why I went back to subaerial studies.

BMR: Right, it’s easier going with your car, taking samples, and going to the lab.

HM: But actually, I returned to the scientific ocean drilling project after… Maybe more than five years, after my decision to leave the ocean (laughs).

Probably five years later, one of my colleagues, [Toshitaka] Gamo-san, Professor Gamo at the Ocean Research Institute – when I was a graduate student and postdoc at the Ocean Research Institute, Gamo-san was an Assistant Professor there, and we shared the same room. We communicated really well. But after 5 years I left the ocean, he asked me or he invited me for a cruise of the Shinkai 6500 [note: a deep-sea submersible]. I refused once, because I didn’t want to go to the ocean and also, I don’t like very small spaces – I don’t know the English name.

BMR: Claustrophobia?

HM: Yeah. It was terrible to stay in that very small bell. So, I refused once, but my husband said to me, “It’s a really special experience that not everyone can do. You should go”. So, I thought… I returned to the ocean sciences, there. After that I joined some cruises, mostly to go to the Mariana Trough, the Philippine Sea plate.

After that, maybe it was 1993 or 1994, the JR went to the Nankai Trough, and they got a very long core from Muroto. Azuma-san was looking for scientists to analyze the sediments, and clay mineralogy, which was one of my specialties – as I said, I studied water-rock interactions, so I learned many techniques to study clay minerals. So, I agreed to analyze the core samples. That was my second encounter to the ocean drilling program. And I analyzed those, studied them, and wrote a few papers about diagenetic reactions and the water-rock interaction matters. That was a chance to return to the ocean drilling program. After that, I didn’t join any other ocean drilling cruises for a while, but I became an SPC (Science Planning Committee) member. I’m not sure when it was, maybe 2003 or something.

BMR: Before continuing with scientific ocean drilling let me ask you a quick question – did you enjoy the Shinkai diving?

HM: Oh, yes! (both laugh). I was really terrified to dive. Before diving, I wanted to go back to land, but I made up my mind, went into the submersible, and came back to the surface. I thought it was really nice, for me, to continue being a geochemist.

BMR: For these kinds of experiences?

HM: Yeah. It was a really, really good experience. I thought it was really nice to be able to continue in this work, so I could see a really good world, a beautiful nature, very unique. What most people cannot see.

BMR: That’s so nice. So, going back to the JR – did you mention that you went for the second time in 93-94?

HM: I couldn’t join the cruise; I just gave support as an on-shore scientist.

[interruption]

BMR: so, let’s continue talking about this part of your career, when you went back to scientific ocean drilling. Is there something specific that you want to talk about this period? I’m thinking, for example, that ODP was going to transition into IODP, Chikyu was going to be built… Maybe you have some specific memories of that time.

HM: Uhm… I don’t have so many memories about the transition from ODP to IODP, because I wasn’t so much involved on it. After starting the first IODP, I got involved in management, like being an SPC member or some other committee member. I started in that – not really scientific. So, I didn’t remember so much the transition state.

BMR: What kind of things attracted you about management, instead of science?

HM: Attracting? Is not attracting. It’s just a sort of obligation (laughs). I felt some sort of responsibility to support this kind of scientific programs. I had learned so much… As you know, I was not a really deeply involved person in the ocean drilling programs then, but in any case, I was the first women scientist to join the Ocean Drilling Program from Japan. And even I stopped to do ocean research work, I was – and still am now – an Earth scientist, and my research concerned oceanic crusts. So, people asked me to get involved in the management of the program. I couldn’t refuse (laughs). I just hoped that I could help them. That was my motivation – not really scientific, at that time.

BMR: So, it was like, “there’s no more women involved in Japan, besides you”?

HM: Yeah.

BMR: You mentioned you first got involved in the SPC. Is this the…?

HM: Science Planning Committee.

BMR: What kind of things surprised you about that Committee? What kind of things did you learn when you first got into that committee?

HM: It was not only about the SPC, but I learned so many things from such kind of committees… Even now, although I’m retired, just a few months ago I was involved in that kind of [committees], making the new scheme of the ocean drilling program. I was involved in those discussions and, through all of them, I learned so many things about democracy (laughs).

It’s really a democratic process, and I learned so much about it and about the importance of discussions taking time. It takes so much time, to understand each other, and you have to say clearly what you want to say. You have to have an understanding of each other. I learned that in such kind of processes, communication and the democratic process to decide something are very important. It was really impressive and very important, for me, to learn such kind of processes.

BMR: In your experience, what kind of differences are between the Japanese community and people from other countries, in terms of maybe cultural ways to organize meetings?

HM: Principally, it’s not very different. I suppose Japanese people – it depends on the communities, but what I know, the communities have democratic processes to decide something, and they have many discussions about that. But, you spent more time in communicating with foreigners [in international committees]. It’s really tiresome for Japanese (laughs), because most of Japanese people are not really good for discussion (laughs). So, it’s tiresome but I learned it’s really, a very important process to decide something.

BMR: What other positions you’ve occupied in the IODP, besides the SPC?

HM: I cannot remember, but I attended so many meetings, as a representative of JDESC. I can’t remember the abbreviations; so many abbreviations…

BMR: Oh, were you always involved as representative of JDESC?

HM: Yes, yes.

BMR: From your perspective in JDESC, how the community of Japanese people involved in scientific ocean drilling has changed in these 20 years of JDESC?

HM: Uhm… it’s difficult to say. It’s not so different after the previous project started. JDESC was established when the previous project [IODP] started, at the same time. Before that, we didn’t have an organization like JDESC. So, after establishing JDESC, I suppose it’s not very so much different. But we learned so many things… Same as me, the JDESC also learned so much about the importance of these arguments, and understanding each other, and other democratic processes. Maybe such kind of experience changed the organization. But principally, I don’t think it has changed so much.

BMR: From JDESC, what kind of things have you done to keep the community involved, or to attract more women and more early career researchers into scientific ocean drilling?

HM: It is important to keep the level of community’s activities high. It’s very important to proceed and succeed to the next generation. And also, diversity is of course very important to keep the community organization healthy. So, having different situations, different opinions, different thoughts, and different states… We have to understand each other, and we have to select the best way for as many people as possible. So, for selecting such kind of way, it’s very important that we will consider the diversity, including women and young scientists.

BMR: Looking back intime, was there any decision that should have been different, and a good decision to move forward the Japanese participation in IODP?

HM: Only one solution is scientific interest. That is only one solution. We have very important and interesting subject to fight, to challenge, with many people together, and we can propose such kind of scientific purposes. That is the most important, to continue and develop the community.

BMR: Also looking back at your career, what has been the most important thing for your life or career that you take from your involvement in scientific ocean drilling and ocean floor exploration?

HM: For me? (laughs) It’s difficult! I have already retired and I changed my subject to recycling energies.

BMR: But maybe there are some important learnings…

HM: Yes, there is. From my experience, as I said, I studied subaerial hydrogeochemistry related to tectonics, but learning about the water cycle in the oceanic crust and in  convergent margins gave me a really good inspiration about the material circulation of water, and energy circulation between the oceanic and the continental crust. That is a very important thing for me, to learn both about the oceanic and continental crusts.

Today, I had a presentation in a session, and I talked about mercury emissions in south-west Japan. It’s very interesting that this gaseous mercury is emitting probably in association with the dehydration of a slab of the Philippine Sea plate. Such kind of inspiration, probably, if I didn’t had the experience of analyzing the sediments of Nankai Trough, I wouldn’t have it.

I just mentioned the chemical analysis of the longest hole drilled at Muroto at that time. I joined some drilling cruises at the Nankai Trough with Chikyu, and I analyzed those sediment samples, especially for arsenic and mercury in the sediments. Those experiences gave me the real inspiration for connecting the oceanic and continental crusts. Such kind of experiences made a really good scientific interest. So, to widen the ideas of circulation systems of water and materials, the Ocean Drilling Program was a really a good experience for me.

BMR: Nice. I know you have many stories, and I’m sure I have missed a lot of them in my questions. Is there anything that you’d like to explain? A story, a thought…

HM: I can’t really (laughs). Probably if I take time, I will remember, but not at present (both laugh).

BMR: Should we then finish?

HM: Yes, yes.

BMR: Well, thank you very, very much.

HM: Thank you very much.