Kenji Nogami - Predicting volcanic eruptions with chemistry

"What happens when a volcano erupts in Japan?" asks Professor Kenji Nogami at the Volcanic Fluid Research Center¹ in Kusatsu, Gunma Prefecture. The Great Taisho Eruption at Sakurajima, Kagoshima Prefecture in 1914 was the largest volcanic disaster that Japan encountered in the 20th century. The spread of volcanic ash was reported as far away as Chichijima, Ogasawara, 750 miles to the southeast, and Sendai, 750 miles to the northeast. An equally large eruption could happen in Japan at any time.

"Ash from volcanic eruptions overseas has been known to reach the stratosphere, and ash from large eruptions in Japan can rise to more than 10,000 meters. That is enough to cover the whole Japanese archipelago. Such eruptions have a serious impact on transportation. Air traffic is grounded due to severely decreased visibility and the very real risk of accident due to high-temperature ash clogging plane engines, something that actually happened to a 747 over Indonesia in 1982. Ash can also shut down expressways and rapid rail lines such as the shinkansen. When traffic networks are interrupted, supply chains are affected and the delivery of food and other important commodities is delayed. Some experts predict that Mount Fuji will erupt sooner or later, and there are numerous other volcanos in Japan that may erupt and throw communities and regions into turmoil."

Although phreatic explosions are difficult to predict, Nogami says a method for doing just that is in sight.

There are three approaches to volcano monitoring. The first is geophysical observation. The most traditional method, it involves the observation of real-time physical changes such as earthquake waves, ground transformation such as expansion of mountains, and changes in magnetism utilizing a global navigation satellite system (GNSS) and clinometers. Most active volcanos are constantly monitored in this way.

The second is geological observation. This involves evaluating volcanic potential by estimating and analyzing the form and scale of past eruptions through petrological, geological, and mineralogical survey of the amount and dispersion of ejecta and the chemical composition of lava.

"While geophysical observation can detect volcanic activity, it is still difficult to understand whether magma is involved or to ascertain the current condition of a volcano. Chemical analysis of the ejecta, however, makes it possible to monitor specific changes in volcanic activity. In other words, we can explain whether the volcano will become more active or settle down."

Nogami explains that integrating geography, physics, and chemistry allows us to better understand volcanic activity.

An active volcano is defined as one having fumarolic activity or that has erupted within the past 10,000 years. There are 110 active volcanos in Japan, 47 of which have been designated for monitoring by the Coordinating Committee for Prediction of Volcanic Eruptions, which Nogami is a member of. These are constantly monitored by the Meteorological Agency of Japan. Among them, the observation and research of 25 active volcanos are prioritized. However, only few national universities, including Tokyo Tech, Kyoto University, and Kyushu University, are involved in the project. To make matters worse, a lack of leading researchers looms in the near future.

The Tokyo Tech Volcanic Fluid Research Center has joined forces with the Volcano Disaster Management Council of Kusatsu Town in Gunma Prefecture, where Mount Kusatsu-Shirane is located, and representatives from other prefectures such as Iwate and Toyama, to promote cooperation and information sharing. Unfortunately, the Volcanic Fluid Research Center suffers from a staffing shortage.

"Volcano disaster management has three major pillars: observation, prediction, and action. The Volcanic Fluid Research Center has a volcano observatory that enables us to conduct research utilizing a wide variety of data. In cooperation with the Meteorological Agency, we base our predictions of volcanic activity on this data and information. One result of this research has been that Gunma Prefecture and Kusatsu Town have built a shelter at Mount Shirane that can accommodate 2,500 people. Because the main objective of predicting volcanic eruptions is to save lives, such projects should be promoted in other areas as well. The problem, though, is the declining number of individuals going into this area of research."

"Volcanos are active everywhere in Japan, even when they are not erupting. We need to work together in training more young researchers to prevent a critical shortage of manpower in volcano prediction research and disaster control."

Volcanos are not found only on land, but also in the seas around Japan. Tokyo Tech has conducted a wide array of research in cooperation with the Japan Coast Guard for more than half a century in places as far away as the Ogasawara archipelago and Ryukyu Islands. It has been 10 years since Nogami took over oceanic volcano observation from Professor Osaka, who first became Nogami's mentor during his days at Okayama University.

"The problems resulting from submarine eruptions differ from terrestrial eruptions, but both can have a significant effect on human activity. Japan has 14 volcanic islands that are home to approximately 27,000 residents. If one of these volcanos should erupt, residents can be evacuated. However, it is more difficult to determine if and when they can return to the island. Submarine volcanos also have the potential to affect shipping. If the pumice stones ejected from volcanos get caught up in the engine cooling systems of tankers and cargo vessels, serious problems can result. Volcanic ash can interfere with radar and GNSS. New land masses generated by submarine volcanic activity create issues related to territorial rights and exclusive economic zones, which means that submarine volcano research is directly connected to national interest."

"There is no other town in Japan which takes such advantage of the benefits of volcanos."

Nogami spends most of his time each year in the mountains of Kusatsu. Smiling, he says that he is more comfortable being outside than in the laboratory. When he was a child, he was always at home reading. He read all the books in the library at his elementary school. His parents were very worried, and decided to have him join the Boy Scouts. This started his lifelong interest in nature, and he continues to be a Boy Scout leader to this day. You never know what will be a turning point in your life, he says.

Nogami also has a message for students who are studying science and engineering.

"Try to broaden your view. Look at things from a wider perspective. In order to do so, it is necessary to go out and observe, get out of the virtual world of the lab. Working with actual objects is essential in all fields of research. While this does not always have to be outdoors, you need to see, touch, and observe. You should be willing to reach out and explore. Such experience increases your motivation to improve your skills and deepen your insight."

• Researcher Details | TOKYO TECH STAR Search - Kenji Nogami
• Volcanic Fluid Research Center

Published: April 2016