TOKYO: A type of a sound wave generated by the recent huge eruption of a submarine volcano near the Tonga islands has circled Earth, a Japanese researcher said Monday.

Such a phenomenon was observed for the first time since highly-precise surveys began in 1980s, Kiwamu Nishida, associate professor at the Earthquake Research Institute of the University of Tokyo, said.

Nishida said data collected from microbarometers across the world showed that the generated sound wave had a very long time period of some 1,000 seconds and was inaudible.

A long-period sound wave can travel a long distance without a decline, but “the observed wave even went around the globe because the eruption was so powerful,” he noted.

According to Nishida, a sound wave generated by the 1883 Krakatau volcanic eruption in Indonesia is believed to have gone around the planet. Meanwhile, there have been no reported data indicating the generation of a similar sound wave from the eruption of Mount Pinatubo in the Philippines in 1991.

After the latest eruption of the Hunga Tonga-Hunga Ha’apai volcano, tsunamis reached Japan and many other countries facing the Pacific Ocean.

In addition, atmospheric fluctuations caused by the blast lifted the tide level by up to 1.2 meters on the coast of the island of Amami Oshima in Kagoshima Prefecture, southwestern Japan, the Meterological Agency said.

JIJI Press