Scientist Interview: László Oláh

You have been chosen as one of seven Hungarian and foreign researchers in the “Excellence Program” of the Hungarian Research Network (HUN-REN).  Could you please describe the purpose and objectives of this program, your winning proposal “High-energy geophysics: Earth sciences and geotechnics via measuring cosmic rays” and the research you will work on as you establish and lead your new group at the High Energy Physics Department of the HUN-REN Wigner Research Centre for Physics?

The Hungarian Research Network has been established as recently as 2019, in order to coordinate and support the existing national research institutes, safeguard academic freedom, and improve the competitivity of the publicly funded research sector. Along these lines, the objective of HUN-REN Welcome Home and Foreign Researcher Recruitment Programme is to attract internationally recognized Hungarian (or foreign) researchers previously working abroad to establish research groups at the institutes of HUN-REN. The aim is not only to recruit motivated and excellent researchers, but to orient existing resources efficiently, enlarging national and international cooperation.

The High-energy Geophysics Research Group of the HUN-REN Wigner Research Centre for Physics has been established to develop measurement procedures based on the tracking of cosmic ray muons, to conduct Earth science research and to develop technologies with high social impact. The research group has been launched with 5 members, combining different expertise in research and development of instrumentation, in particle physics, Earth sciences and engineering. Our scientific goals include investigating the geology of the oceanic lithosphere by exploring the large-scale density structure of ophiolites;  researching the active volcanism at Sakurajima and other volcanoes; and studying the structure and dynamics of tropical cyclones. Various social implementation projects are planned via developing muographic methodology and instruments for the assessment of volcanic and atmospheric hazards; mineral exploration for sustainable, efficient and safe mining; passive and non-destructive assessment of infrastructures; as well as the navigation and security applications of muon positioning.

What is the most exciting research and achievements you have been involved with as a Project Researcher of muography at the Earthquake Research Institute of the University of Tokyo for the last six years?

Studying such a gigantic and hazardous edifice like Sakurajima volcano is very exciting. My work focused on the installation, operation and maintenance of the gaseous tracking detectors at the Joint Muography Observatory of the University of Tokyo and Wigner RCP, and the reconstruction, quality assurance and analysis of collected data. These were exciting tasks, but the most intriguing was when we merged and compared the reconstructed muographic density image data with the data acquired by other techniques (such as synthetic aperture radar or gas emission rate monitors) to learn about the nature of Sakurajima volcano. Although mass changes had already been detected at Mt. Asama by Tanaka et al, it was exciting to visualize the plugging of the deactivated Showa crater of Sakurajima in 2018 and demonstrate that muographic data correlates with the volcanic activity which occurred in this hazardous edifice. We have revealed the in-conduit mechanism in the active Minamidake crater and explained the link between eruption frequency and uplifting of volcanic edifice. Such data could help to interpret ground deformation monitoring data and improve hazard assessment. Recently, we have observed an inverse relation between the variations of mass densities measured underneath the two active craters that hints at the presence of a branched conduit structure underneath the active craters which has not yet been revealed to date. 

How has the experience of living and working in Japan changed your perspective and opportunities?

The opportunities significantly increased during my living and working in Japan thanks to the support provided by my professor, the University of Tokyo and the Embassy of Hungary in Tokyo.

I had more chances to meet and discuss with leading experts from different scientific fields and industrial sectors in Japan and at other locations overseas. Working in Japan for almost seven years resulted in lifelong memories and experiences that transformed my perspective about life and science. The field work and collaborative activities with industrial partners have significantly changed my perspective about team work and education. The challenges I faced during my work, either alone or together with partners, changed my personality to be more disciplined, patient and adaptive, as well as helping me to improve team working and problem solving skills.

What are the biggest differences between working in Japan and working in Europe?

Concerning my case, the differences mainly came from the different positions and tasks. From 2010 to 2017, I worked as a graduate student at the High Energy Physics (HEP) Department of Wigner RCP. Here, I was surrounded by internationally recognized experts of HEP, I could learn a lot from my senior colleagues about experimental particle physics. I really enjoyed this atmosphere and I spent a lot of time in the laboratories outside my working hours. During this period,  I had less chances to interact with people from other research fields and from industry than I did later in Japan.

After completing the Ph.D., I came to Japan thanks to significantly contributing to a joint development of Wigner RCP and the University of Tokyo, called the Muographic Observation Instrument (MOI). The technical readiness level of MOI allowed us to contribute to the development of cutting-edge volcano observation technology in the Integrated Program of Next Generation Volcano Research and Human Resource Development of MEXT Japan. This program supported my work at the Earthquake Research Institute (ERI), the University of Tokyo between 2017 and 2023. My work life significantly changed soon after arriving to Japan: besides research activities, I contributed to the technology transfer of MOI and I trained industry partners. During these activities, I also realized that it is crucial to strengthen the links between academy and industry in order to offer better and more solutions to the real problems of society, such as to the need for safer cities or cleaner energy. Although there were more administration requirements in Japan, the international office of ERI continuously supported me to complete all of them, and I could fully focus on scientific research and R&D works.

While I discussed issues with cutting-edge experts of different scientific fields and industries, I realized that I would have to deepen my knowledge in Earth sciences and focus more intensively on their social implementations to bring a different expertise and knowledge back to my alma mater and homeland. I hope that the work experiences and knowledge I have acquired in Japan will allow to me to present another perspective to the next generation of researchers and help my research institute and HUN-REN to achieve their goals.

Generally speaking, working in Japan is neither better nor worse, it is just different and one accepts these differences once one has experienced this culture for a few years. The differences are results of the complex evolution of society and economy which have occurred during the last few decades as well as long-term historical traditions. For example, there are Japanese companies where people enter after graduation and they can work there at different positions until retirement. These companies are more supportive and create better environments, but it is more complicated to keep the balance between work and life. I deeply appreciate the reliability of Japanese partners, we always got the contributions that we expected from them and the team work is quite efficient in Japan. This characterizes all sectors. I see the efforts towards gender equality in the Japanese work environment, but I believe that more efforts are still required to approach it.

What do you think will be highest impact developments to come in future muography research?

There are numerous new developments in muography, (e.g., muon positioning, cosmic coding, cyclone monitoring) that are great innovations in my opinion, and these can extend the capabilities and aid the weaknesses of existing technologies. I believe that a lot of developments are still required for both detector technologies and image processing techniques in muography for exploring the Earth’s subsurface more accurately. Improving the robustness of detector technologies and utilizing machine learning techniques for optimization of experimental designs and muographic image processing techniques, such as those used for recognizing the precursors of volcanic or atmospheric hazards, may lead muography into an advanced phase in which it can  provide more contributions to developing safer cities and societies and providing cleaner energy.