Toshiya Kanamatsu

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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 interviewee has reviewed, edited, and approved the publication of the version here posted.

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Interview of Toshiya Kanamatsu by Beatriz Martinez-Rius on 2024 September 18, D/V Chikyu, IODP Expedition 405, Japan [link]

Beatriz Martinez-Rius (BMR): Today is September 18 of 2024. We are onboard Chikyu, in IODP Expedition 405. I’m Beatriz Martinez-Rius, postdoctoral researcher at JAMSTEC. Can you please tell me your name, affiliation and position?

Toshiya Kanamatsu (TK): My name is Toshiya Kanamatsu, my affiliation is IMG, Institute of Geodynamic Research. My position is group leader of the Marine Geology and Geophysics group.

BMR: Thanks. We can talk later about what is being a group leader.

TK: Okay, yeah.

BMR: That’s a different kind of thing than doing science, right?

TK: It’s kind of management. So I, myself, am a scientist, but now I’m more like a manager, looking after budgetary things, planning the ship schedule, or things like that.

BMR: So maybe not as fun as science.

TK: Yeah, not fun but… I have to push everybody to go onboard…

BMR: What is your field of specialization within sciences?

TK: My specialty is paleomagnetism. It’s the study of magnetization of rocks and sediments. In there, there are small magnetic particles. Their behavior as magnets is a record of the geomagnetic history. And through such a record, we can understand how the magnetic field is produced in the Earth. It is a big, big objective (laughs). Then, the magnetic direction remembers the north direction. In such a drilling project, usually the core comes rotated. We can provide the orientation of the structure and also the age of the core; that’s maybe our duty in this cruise.

BMR: What do you like about paleomagnetism, that has attracted your attention for so many years?

TK: It’s a kind of history. When I was a graduate student I was interested in the tectonics, and if I majored in paleomagnetic direction, I would understand the big movements of an area. In this case, if you know the paleomagnetic direction, you can know if that area has rotated. Using such a record we can understand the tectonics of a structure. In particular, I studied the tectonics of Hokkaido, how Hokkaido formed.

BMR: This was when you were young. Is this reason why you choose Geology, Earth Sciences?

TK: Yes. This was my major interest, but the first step was a professor, who provided me paleomagnetic studies. Paleomagnetism can provide the age (of formations). At that time, I was interested in Cretaceous age features. Dinosaurs were walking but some event, a cosmic impact, happened. We have to know the age of the Cretaceous structures. In that case, paleomagnetism is used, so that professor recommended it to me. That was the first step.

BMR: So, let’s go back to the beginning and start from there. Just to understand your background, I’d like to ask you where did you grow up and what kind of job did your parents do?

TK: I come from Nagano, which is in the center of Japan, a mountain range. I was born in there. At that time I’d like to study at Hokkaido, so I entered at Hokkaido University. At that time, I tried to study agriculture, there (laughs), but accidentally I moved to Geology and then I continued in Geology.

BMR: (laughs) What does it mean ‘accidentally’?

TK: (laughs) Accidentally… After entering at university we had to study, but if the score was not good, I couldn’t choose the department by myself. So, (laughs) geology was… My second option.

BMR: Did your family had any relation to agriculture?

TK: No, no, not at all. My father was a doctor so, very different. But maybe, growing up in a mountain range, I was interested in plants, trees…

BMR: Geology is also related to the mountains and being outdoors. Did you have any professor or mentor who directed your career?

TK: I entered into the Ocean Research Institute (ORI, University of Tokyo), and my supervisor was (Asahiko) Taira-sensei. So because of Taira-sensei, I decided to study marine geology. At that time, we had the opportunity to join ODP cruises because in each cruise, Japanese had two beds. But, sometimes, there were no applicants from Japan. Then, Taira-sensei ordered his students, “Go! Go!” (laughs), so then I joined the ODP Leg 149. It was my first cruise.

BMR: I was checking the legs you had been involved; Leg 149 was in the Iberian margin.

TK: Iberian margin, yes.

BMR: How did you end up studying the seafloor in the other corner of the word?

TK: I had no choice. It was just order from Taria-sensei (laughs).

BMR: What kind of things did you do, in that expedition? I’m interested in understanding what you could transfer from your research around the Iberian Peninsula to your studies around Japan.

TK: At that time, I tried to study the paleocurrent of turbidites and the contourites around the Iberian margin. One big objective was to study the serpentinization of the ocean floor. And the second objective was kind of study the paleoceanography in the Iberian Margin. The contourite is a kind of agent of climate change, so I tried to study it by using paleomagnetism. Because paleomagnetic research can provide direction, if I could provide it, maybe we could understand the flow direction of the turbidites and the contourites.

BMR: I have two follow-up questions about that expedition. The first one is, I would like to know about your first impressions of life onboard, and scientific collaborations… What do you remember about that expedition?

TK:I remember… At that time, my English conversation wasn’t good. But… there was no other Japanese (scientist), in that Leg. Fortunately, (Kazushi) Kuroki-san was a technician. He helped me a lot. And, about the science, maybe my understanding was very low. However, other experienced people, many experienced people, helped me. So, I could survive (laughs).

BMR: For two months.

TK: Two months, yeah. It was too long; however it was nice experience. So, I still have good connection with cruise members. Most people is getting older, but sometimes I could meet them in meetings. Even though if it’s not for science, such relationships are sometimes important, I think.

BMR: I think this is something that you can also see here in this expedition. People starts building connections, and many times, it is for all the career. It’s something very nice that I’m realizing.

TK: Especially in that expedition, as I told you, you meet for the first time maybe people, and maybe from different specialties. So, without communication, it may be difficult to spend two months.

BMR: I’ve heard that Kuroki-san was in the same situation, when he arrived to the JR (JOIDES Resolution). He could not speak English at all.

TK: Yeah. At that time, I felt that my English conversation was not good. However, we worked together in the same material, so we could communicate without a good English, I think (laughs).

BMR: How the technologies and the way you study paleomagnetism has changed, from those years to the work you are doing now?

TK: Uhm… Not so much, I think. Because at that time, we already had good instruments. The magnetometer that was installed in the JR is the same type as the Chikyu’s. So, not so much change in the technology, I think.

BMR: That’s interesting.

TK: There’s no technological change, but we have been able to collect many data from worldwide. Such a data is important to understand the global geomagnetic field. So, especially the JR, it has collected lots of samples by hydro-pressure Hydraulic Piston Coring System. It was a very nice material for paleomagnetists. So, we could collect lot of samples that have been the most important for our paleomagnetic community, I think.

BMR: How did you continue your research, after that first expedition?

TK: That story was in my PhD time, but I need to find my next job. At that time, I found a postdoc position in JAMSTEC but, at that time, I didn’t know what JAMSTEC was (laughs). That was before the IODP phase. When I was moved to JAMSTEC, I found out that JAMSTEC was trying to start the OD21 Project. It was at the very beginning of IODP. So, at that time, there was not much people involved. However my supervisor, Hajimu Kinoshita, he tried to… Firstly, he tried to have a conference to consider the scientific objectives for the OD21. And it was successfully done. So the ministry, Monbusho (Ministry of Education) was convinced that JAMSTEC could do next IODP phase. Then, they provided provide the budget to build Chikyu. I was a very small voice, so I don’t know the details… I couldn’t understand the details. However, I worked under Hajimu Kinoshita-san.

BMR: That’s a very interesting part of history, when Chikyu was discussed and decided. Do you remember how was the environment like, or what people said about the construction of the ship… Some image that helps us understand how was the situation at JAMSTEC when Chikyu was planned?

TK: At that time, most scientists or staff in JAMSTEC maybe didn’t know about the Ocean Drilling Program. However, JAMSTEC was the only possible institute to build or proceed with the IODP. Before that, maybe it was the ORI, as a kind of Japanese agency… However, it had not so much budget. During the ODP, I think that was one of the kind of problems. They couldn’t deepen the holes because deep holes are usually unstable. So the ODP people recognized the need for the technology, a riser system. At that time, maybe the Mohole Project was still kind of goal – to go to the Moho. Worldwide, people pushed JAMSTEC to make Chikyu, I believe. That’s my understanding. So, to endorse such a ship, we needed to have international meetings, like… the CONCORD.

BMR: The Conference on Riser…

TK: Yes. JAMSTEC organized it.

BMR: Did you attend?

TK: Yes, I was a secretary support. Hajimu Kinoshita asked me to make some support for the meeting, yes. And then, at that time, maybe four topics were chosen during the meeting’s conclusion. Then, the Nankai drilling was highly prioritized. Monkasho (abbreviation for Japan’s Ministry of Education, Culture, Sports, Science, and Technology) was glad to see such things, because the Nankai earthquakes are very important for Japan’s natural hazards. I don’t remember exactly, but maybe four or five important topics were chosen at the end of CONCORD.

BMR: Did you got also involved in Nankai research?

TK: Yes.

BMR: How come?

TK: At that time, my specialty was paleomagnetism (laughs). So, at that time, my duty was to organize the stratigraphy[?] and maybe the orientation of the core. My knowledge was not so strong on fault rocks… But the first stage of the Nankai Trough project (NanTroSEIZE) was a shallow portion drilling, so I had a lot of chances to join the IODP expeditions. The second stage was deeper, so… My paleomag was not so useful (laughs).

BMR: So paleomag is more useful in shallow drilling?

TK: I think so. I need intact sediment, not disturbed sediment, and not tilted. Horizontally stratified (sediments) are better for reconstruction, I think.

BMR: Do you always study sediments from the seabed?

TK: Usually sediments, why? Because sediments have a bedding plane. So, we can know what is the horizontal plane. However, the hard rock, maybe it is a little bit difficult to know where is the horizontal plane. Because geomagnetic field needs some reference, if the horizontal plane is like in this direction, it is totally different. So, sediments usually have a bedding plane, so I like for the drilling project.

BMR: On how many expeditions have you been onboard?

TK: (laughs) How many expeditions… IODP, maybe four.

BMR: Including ODP?

TK: No, three ODP legs. Seven in total.

BMR: Seven in total! That’s a lot. What do you like about these scientific ocean drilling expeditions?

TK: Material itself is very precious, because we couldn’t get such materials using any other ship. That is very attractive to me. And also, not only paleomagnetic data, but I we can refer to other people’s data. So, a more comprehensive interpretation is possible by ODP and IODP material. It’s a kind of advantage, I think.

BMR: It’s very interdisciplinary.

TK: Yes, interdisciplinary.

BMR: Different specialties and disciplines looking at the same problem.

TK: Yes. Sometimes it’s very exciting. I have never had such idea before, but they are having such exciting ideas.

BMR:  That’s right, in these discussions you can come up with ideas you’d never had before. So please, tell me please about these IODP expeditions. I know that you were co-chief of one of those.

TK: In Expedition 306, that was at the very beginning of IODP for Japanese community. So, we couldn’t collect that much people. For every cruise, we hoped to send eight Japanese researchers, but each expedition was two months long. Two months, two months, two months… Maybe six expeditions per year, so fifty Japanese were needed per year. It was very difficult. Not only for scientists, but for co-chiefs was also difficult to… (laughs) At that time I had experience on ODP and paleomagnetism, so somebody pushed me to go (laughs), “go!” (laughs)

BMR: How is it like, the experience of being a co-chief?

TK: It is a… We have to make, sometimes, tough decisions. During that cruise, EPM – at that time the name was different, ‘staff scientist’. Staff scientists helped us a lot. So… I feel it was no so much difficult. But sometimes, communication between science party was not good (laughs). This time (expedition 405) everybody is very friendly, but sometimes, a strange guy appears (laughs) and disturbs the… Because being for two months, without… isolated in the ocean, is a very strange situation for normal people. So I understand that people sometimes cannot do well. But at the end of the cruise, most people can be happy. So, it was nice. We can … share an emotion (laughs) not only science.

BMR: I think it’s not only two months, but also the… style. Because we are working 12 hours, sometimes more because we extend our shifts. So, I understand that at the beginning is a lot of excitement, but towards the end we start to lose the energy, and maybe there are some frictions… So, it is important to get good rest.

TK: Uhm. Sometimes we need to refresh. Today, we had a birthday party for Marianne (Connin), so it was nice. And in the JR, we had a refreshment every Sunday. They made a BBQ outside, so it was… oh, we could change our condition. So, sometimes these events or activities…

BMR: Yes, I think it’s necessary, because otherwise everyday ends up being the same.

TK: Yeah, especially this time. We have no sample data yet (laughs), so it is difficult to keep our condition…

BMR: We hope that it will arrive soon. Now that we were talking about the community, when IODP started, the Japanese community was not very big. So, how the community of scientific ocean drilling has changed in this 20 years, in Japan?

TK: At the beginning, the IODP community was very small. Now it is growing, and I think that now many people is interested in joining the IODP cruises. Actually, for some core of the expedition, now many people submit applications (for getting samples). Before, there were no applications. So, “I have core… could you join IODP, or…?” (laughs). Gradually, however, we now have, Japanese have a lot of experience. And they also join people who finds that IODP studies are very interesting and can publish good papers or… So, if a person experiences what is a nice IODP cruise, then they can encourage young people that has not joined before. So, it’s gradually growing.

BMR: Why do you think that people did not apply so much, before?

TK: Maybe because they had no experience. Even ocean research itself, it was not so familiar, before. At that time JAMSTEC, not only IODP, also provided joint cruises using small ships. JAMSTEC opened up opportunities, and marine geology became more popular, I think. Most people, and even me, studied in the mountains (laughs), the mountains’ field.

BMR: How JAMSTEC has changed in these years, since IODP started?

TK: Too many changes, I think. Uhm… too big changes (laughs). Not only for science, but JAMSTEC had to take care of the drillship operations. So CDEX – maybe you know CDEX – had a very different culture from previous JAMSTEC style, I think. However, it was successful. I think that, now, MarE3 can control not only small ships, but also IODP. For science… Previously, we had a special department for the IODP studies. However, it was separated into a different department. Actually, there were not so much science specialists. Especially in our institute, there are many seismologists (laughs). But, in JAMSTEC, we collaborate with from outside institutions, like universities, so… I think it’s not such a big problem.

BMR: You mean that, since IODP started twenty years ago, JAMSTEC has now more scientists that work on seafloor studies.

TK: Uhm.

BMR: And also, that the creation of CDEX was kind of deferent within JAMSTEC, but now everything kind of came together in MarE3, right?

TK: Yes.

BMR: Were you a member of CDEX?

TK: No, I was outside, however, at that time, JAMSTEC was not so big, and communication was easy to reach the CDEX people.

BMR: How scientific ocean drilling has contributed to your career?

TK: I had the opportunity to write papers (laughs). It is kind of an evidence of the IODP cruise. Usually, we submit sample requests and publication was kind of an obligation, if we submit sample request. So, because of such a rule, I could push myself (laughs) to make some publications. And… But only such an aspect… The samples taken by IODP are by themselves a very precious thing. So, not everybody can study such materials. It has been a good advantage to my career, I think.

BMR: You have a lot of experience in paleomagnetism and in scientific ocean drilling. Have you had the opportunity to be a mentor of some early career researchers?

TK: Uhm.. sometimes, Because onboard – in this case, I have a partner and he is a young person, so I have to take care of him… When some kind of thing  happens, I can teach them about that. In my department, in my group, usually we can work together on the same cruise. However, I can’t share my experience with them. My group is not so big, maybe only two geologists… They will join, one will come to the window 2 (note: second scientific party of IODP Expedition 405). So, yes, I try to provide my experience to the young people.

BMR: That’s actually the way in which knowledge can continue growing.

TK: Yes.

BMR: Why did you apply to this expedition?

TK: I had been studying the paleo-seismology along the Japan Trech, and it was kind of the history of the earthquake. So I would like to know the timing, the interval between big earthquakes, how many years. But now (in this expedition), I’m interest ed in how big earthquake occur, and to understand such a thing maybe we need to sample the damaged zone. However, my understanding is not so big (laughs). So I need to understand it from my colleagues in this expedition.

BMR: This is something good, right? To understand that even very experienced scientists come here and have to learn some of the things.

TK: Yes, yes. Experience is important, I think; and we have to share it with other people. I think this is a kind of key point of the IODP community.

Toshiya and other members of the IODP Expedition 405, looking at the just-retreived cores. Credits: ©️Doriane Letexier / JAMSTEC / IODP

BMR: So, inside JAMSTEC, you moved from a scientist to a managerial position. I’d like to ask you what kind of things have changed for you, and what kind of things remain being the same?

TK: Uhm… The people itself is the same people, in JAMSTEC. However… The director respects our direction; however we cannot change major (things). So, basically we can go in the same way, same direction. It’s difficult to explain (laughs) JAMSTEC changes each five or seven years. Sometimes, the direction changes because the world changes. However this, I heard that IODP will continue in IODP³, so maybe this culture continues. But the size and the number of expeditions, maybe it will change a little bit. But I think that the spirit of IODP has not changed. Same thing, I think. I hope so.

BMR: I think so. Because when I talk to people like you, who started in IODP, and I talk to early career, who are starting here, you say the same kind of things about the experience. How do you see the future of scientific ocean drilling?

TK: I’m not sure. However, the big difference from ODP… ECORD, the European side, appeared. It became very flexible, the cruises. Before, ODP were two month cruises, and deep drilling. So maybe, for the next step, the ECORD-type of expedition is much needed because… Of course, we depend on the budget, but if we have the flexibility, maybe we can go in a different direction. And maybe, we can continue. IODP itself should be changed to adjust the world changes. In this moment, flexibility is kind of important, I think.

BMR: So how would you like to continue involved in scientific ocean drilling?

TK: I’m getting old, but I encourage young people to join. But old people, maybe can also join.

BMR: The ship is very comfortable (laughs)

TK: (laughs) I think so, yes. If I have opportunity, I’d like to continue joining.

BMR: I’m sure you will have opportunity. Before finishing, is there something that I have not asked you, that you would like to explain or talk about?

TK: Uhm… No drink (onboard) (laughs) is a very interesting situation. For two months. But, after two months, beer is very nice (laughs) only a small amount of beer can make happy me (both laugh).

BMR: I’ve heard this sort of stories before (both laugh). Thank you very much.

TK: Thank you.