Researcher Information


Assistant Professor

Elucidating mechasnisms of volcanic activity by observation and simulation

Institute of Seismology and Volcanology, Volcano Physics


Understanding mechanisms of volcanic activity based on numerical simulation of fluid flow and field observation

FieldPhysical volcanology, Fluid mechanics, Thermodynamics
KeywordActive volcanoes, Eruption forecasting, Volcanic hydrothermal system, Volcano observation

Introduction of Research

While volcanoes give us benefits such as magnificent landscapes and hot springs, they can be a threat when they erupt. It is important to predict volcanic activity in order to maximize benefits and minimize threats. Many observations have been made to predict the onset and the sequence of the eruption, and for some volcanoes, it has gradually been known what would be observed before the eruption. However, if the earthquake increases, if the ground inflates, it does not always lead to an eruption. In order to predict the next activity from the observation, it is necessary to clarify the underground mechanism to explain the observed value. Therefore, using a method called a numerical simulation of hydrothermal flow, we investigate how hydrothermal fluid behaves inside the volcano and how it affects ground observation during inter-eruptive stage (Fig. 1). At the same time, we obtain the data at some volcanoes for the numerical simulation of hydrothermal flow and elucidation of the mechanism of volcanic activity (Fig. 2). Recently, I am also challenging volcano observation using a drone.

Fig. 1 Distribution of change in temperature and pressure 1 year after given a condition.
Fig. 2 Visible image and infrared image taken of Nakamachineshiri Crater at Mt. Meakandake.
Fig. 3 Lava filled the summit crater of Shinmoedake, taken by using drone (2019. 3.5).

Representative Achievements

Contention between supply of hydrothermal fluid and conduit obstruction: Inferences from numerical simulations, R. Tanaka,, T. Hashimoto, N Matsushima, T. Ishido Earth Planets Space, 70:72 (2018).
Permeability-Control on Volcanic Hydrothermal System: Case Study for Mt. Tokachidake, Japan, Based on Numerical Simulation and Field Observation, R. Tanaka, T. Hashimoto, N Matsushima, T. Ishido, Earth Planets Space, 69:39 (2017).
Transition in eruption style during the 2011 eruption of Shinmoe-dake, in the Kirishima volcanic group: implications from a steady conduit flow model, R. Tanaka, T. Hashimoto, Earth Planets Space, 65, 645-655 (2013).
Academic degreePh. D. (Science)
Self Introduction

I am from Saitama. I played football (soccer) until high school and American football at Hokkaido University. Now, my hobby is Yoga and bouldering.

Academic background2012 Graduated. School of Science, Hokkaido University
2014 Master course finished. Graduate school of Science, Hokkaido University
2017 Doctoral course finished. Gratduate school of Science, Hokkaido University
2017-2019 Researcher, Faculty of Science, Hokkaido University
2019-Present Assistant Professer, Institute of Seismology and Volcanology, Faculty of Science, Hokkaido University
Affiliated academic societyThe Volcanological Society of Japan
Room addressFaculty of Science Builting 4 4-312

Institute of Seismology and Volcanology, Volcano Physics


Assistant Professor

What made you decide to become a researcher?

I did not concern much about my future. I was immersed in club activities, playing football in high school and American football in university. In my third year of undergraduate school, I visited the Usu volcano during practical training and was first fascinated by its grandeur. Assigned to a laboratory, I gradually became fascinated with studying the volcanoes while enjoying its bounty of hot springs, delicious food, and sake. Later, at a conference where I gave my first poster presentation, I felt the joy of research and discussion with others and decided to become a researcher.

Picture by UAV at Gin’numa crater at Usu volcano.
Please tell us what you think is good about your lab.

First, we have many students and staff interested in a wide range of subjects – earthquakes, volcanoes, and tsunamis – and work together on research activities. We have about 20 students, from 4th-year undergraduates to Ph.D. students, and about 20 staff members, including faculty and technical staff. Many students make for lively and wide-ranging discussions.

In addition, since fieldwork is the primary research method, we can go to various places in Hokkaido and other parts of Japan and overseas. I also had the opportunity to go to Alaska and the Kamchatka Peninsula, a valuable experience I could not have had otherwise.

Kamchatka, Mt. Abacha.
Please tell us about yourself; things you are good at, your favorites, hobbies, and daily routines.

I enjoy interacting with my dog, a somewhat rare breed of Bedlington terrier. I take my dog out to the dog run almost every weekend. I have also started running to climb and study volcanoes by myself for as long as possible. I mainly run 5-10 km but would like to try a 100 km ultramarathon someday.