Researchers say tidal levels observed around Japan following the recent volcanic eruption near Tonga may have been influenced by atmospheric vibrations.

Professor Imamura Fumihiko of the International Research Institute of Disaster Science at Tohoku University led the study.

It was based on the fact that tsunami of about 1 meter were observed near the undersea volcano after it erupted on January 15.

The group ran a simulation hypothesizing that tsunami were directly caused by the eruption. The outcome largely matched actual observation data, but there were some key differences.
In the simulation, the initial tsunami wave reached Japan about six hours later than the actual first observed change in tidal levels.

Also, the height of the tsunami in the simulation was lower than in reality by one-half to one-ninth.

Professor Imamura says it is highly likely that these differences can be attributed to air vibrations that changed the atmospheric pressure following the eruption.

He said although tsunami caused by volcanic eruptions are rare, it could happen again.

Imamura added that he hopes to gather more knowledge and use it for disaster prevention.