Beijing, 8 Sep (Xinhua) -- The eruption of the South Pacific island nation Tonga's Hon'aha Apayi volcano has set another record. A paper published in Science magazine on the 7th pointed out that the eruption of the submarine volcano in 2022 triggered a large-scale underwater debris flow, which flowed at the fastest speed on record and far exceeded expectations, resulting in serious damage to submarine cables 80 kilometers away.
Like terrestrial volcanoes, submarine volcanic eruptions also produce large amounts of volcanic ash and lava flows, but they occur mainly underwater, which in turn causes special torrents that envelop large amounts of lava and other materials on the seafloor, that is, underwater mudslides.
This is a multi-channel composite map of the Fengyun-3E star provided by the China Meteorological Administration on January 15, 2022. The figure shows that the texture structure of the volcanic ash mushroom cloud formed during the eruption of the volcano in Tonga is clearly visible, forming an umbrella-shaped cloud with a diameter of nearly 500 kilometers, and a ring-shaped shock wave appears around the umbrella-shaped cloud and spreads around. Xinhua News Agency (Photo courtesy of China Meteorological Administration)
The study was led by the UK's National Oceanographic Centre and the New Zealand National Institute of Water Resources and Atmosphere. Based on the timing and location of the damage to the submarine cable, the researchers estimated that the debris flow speed was as high as 122 kilometers per hour, faster than a mudslide caused by an earthquake, flood or storm.
Lead author Michael Claire, a scientist at the UK's National Oceanographic Centre, said the impact of the underwater mudslide had a range of more than 100 kilometers and damaged submarine cables.
Emily Lane, chief scientist at New Zealand's National Institute of Water Resources and Atmosphere, said sediment from underwater mudslides mixed with other material covered the submarine cable, which was up to 30 metres thick. "Impressively, the Tonga cable is buried in an undersea valley south of the volcano, which means the mudslides are powerful enough to rush up the mountain, over the huge ridge and down."
This is a post-tsunami photograph of the outskirts of Nuku'alofa, the capital of Tonga, after the tsunami. Xinhua News Agency (Photo courtesy of Ha'atafu Resort in Tonga)
The study is the first to record what happens when large amounts of erupting volcanic material flow directly into the ocean, AFP reported.
A large number of volcanoes are located on the ocean floor, but only a few are monitored, the researchers said. The study helps scientists better understand the dangers of submarine volcanoes worldwide, such as the risks to coastal human communities and critical infrastructure.
An undersea volcano erupted on Hong'aha Apai Island on January 14 and 15, 2022, rupturing Tonga's only submarine communication fiber optic cable, observing a tsunami 65 kilometers away in Nuku'alofa, the capital of Tonga, and issuing tsunami warnings from Japan, the United States, Canada, New Zealand, Australia and other countries.
This is the Honga Ha'apai Island in Tonga taken on November 5, 2015 (file photo). Xinhua News Agency (Photo by Shane Cronin)
A year after the eruption of Tonga's submarine volcano, more and more relevant research results have been published, showing the power of this eruption: it is the "largest explosion" in the Earth's atmosphere in 140 years; It triggered 25,500 lightning bolts in 5 minutes; sent about 4 million tons of water vapor into space; and the volcanic plume exceeded the troposphere at a height of 57 kilometers, the highest volcanic plume ever observed. (Wang Xinfang)
Source: Xinhua News Agency