BEIJING, Sept. 11 (Xinhua) -- Chinese researchers have discovered the oceanic internal waves generated by the Tonga volcano eruption, according to a recent research article published in the journal Acta Oceanologica Sinica.
Internal waves are widely distributed at the marginal seas or continental shelves. They have an amplitude of up to hundreds of meters and wave crests of several hundreds of kilometers, and affect ocean environments significantly, said the article.
But the internal waves are rarely observed in open ocean areas because of the strong dispersion effect in the deep ocean. The researchers from the Institute of Oceanology and the Center for Ocean Mega-Science, both under the Chinese Academy of Sciences, reported the observation of the internal waves generated by the Tonga volcano eruption.
The Hunga Tonga-Hunga Ha'apai volcano near Nuku'alofa, the capital of Tonga, erupted violently and triggered a tsunami in January.
Satellites captured the eruption of the volcano and the atmospheric turbulence it generated around the globe.
Using the satellite images, the researchers observed clear internal wave packets propagating in different directions, said the article.
The length of the internal wave crests ranges from less than 20 km to 67 km. And the characteristic wavelength ranges from 860.9 meters to more than 1,530 meters, which is the typical value of internal waves.
The study shows that volcanic eruptions not only cause fluctuations in the atmosphere but also trigger dynamic processes such as internal waves in the ocean. ■