Beijing, January 19 (Xinhua) -- The recent violent eruption of a volcano in the South Pacific island nation of Tonga may be the world's largest undersea volcano eruption in 30 years, which continues to attract global attention. According to the Tonga government statement, the eruption has killed 3 people and injured some people. What impact did the eruption and the tsunami it caused have on the environment, economy and people's livelihood? Please look at the Xinhua Reporter's online report on experts from many academic circles --
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Expert: The biggest impact was the tsunami
Be wary of another eruption triggering a tsunami
Located about 65 kilometers north of The Capital of Tonga, Nuku'alofa, The Island of Hong Aha Apai began to erupt on the morning of the 14th and erupted again on the afternoon of the 15th. Countries such as Tonga, Fiji, Samoa, Vanuatu, Japan, the United States, Canada, New Zealand, Australia and Chile have issued tsunami warnings. The Tonga government issued a disaster briefing on the 18th, saying that the volcanic eruption triggered a tsunami as high as 15 meters, causing an "unprecedented disaster".
This imposition photo shows a satellite image of Aha Apayee Island in Tongahun taken by the Worldview02 satellite on April 11, 2021 (left) and a satellite image of the island after the volcanic eruption taken by the Gaofen I satellite on January 17, 2022, with an orange curve showing the original outline of the island according to geographical coordinates. Xinhua News Agency (Courtesy of Xinhua Satellite News Laboratory)
Dr Emily Lane, a fluid dynamics and tsunami research expert at the New Zealand Institute of Atmospheric and Water Resources Research, said that most tsunamis are caused by underwater earthquakes, and only about 5% of tsunamis are caused by volcanic eruptions, and the scale of the tsunami caused by the eruption of the Tonga volcano is huge, and the previously recorded similar event was the tsunami caused by the 1883 eruption of The Krakatoa Volcano in Indonesia.
This is a product map of the January 15 Fengyun No. 3 E star quasi-constant contrast (low-light image enhancement) provided by the China Meteorological Administration. The figure shows that the texture structure of the ash mushroom cloud formed during the eruption of the Tonga volcano is clearly visible, forming an umbrella-shaped cloud with a diameter of nearly 500 kilometers, and a circular shock wave appears around the umbrella-shaped cloud, spreading around it. Xinhua News Agency (Photo courtesy of China Meteorological Administration)
Cronin, a volcanologist at the University of Auckland in New Zealand, made a landfall in 2015 to visit Hon Aha Apay Island. He said the submarine volcano had a series of small eruptions in 1998, 2009, 2014 and 2015. At present, the most serious impact of the eruption is the tsunami, which is not small in some Pacific coastal countries. The tsunami also caused some casualties and property damage in Tonga, but it mainly affected low-lying areas along the coast, most of which escaped.
Cronin said it's hard to predict what will happen to the volcano at the moment, and it may erupt again, but the eruption will not be as violent; because the volcano is located in a shallower underwater location, if an eruption or collapse occurs, it may trigger a tsunami again, but it may not be so large.
Medium eruptions in large volcanoes
Be wary of volcanic ash and acid rain
Oliver Nebel, an associate professor of high-temperature geochemistry at Monash University in Australia, told Xinhua that volcanic ash is actually tiny rock particles, if the aircraft passes through it, the windshield will be damaged, and the volcanic ash particles will melt and crystallize in the aircraft engine, which may cause the engine to stop, which is dangerous, so the volcanic ash will affect air traffic.
This is The Hong Aha Apai Island in Tonga taken on November 3, 2015 (file photo). Xinhua News Agency (Photo by Cronin)
Professor Cronin said that compared with the 1991 eruption of Mount Pinatubo in the Philippines, the shorter eruption time of Hong Aha Apay Island means that the eruption of lava, gas, rock debris and other volcanic material is relatively small, and it is expected to be a medium-scale large volcanic eruption. Fortunately, most of the volcanic ash fell into the sea, allowing the people of Tonga to escape the disaster. However, acid rain from volcanic ash could affect Tonga and eastern Fiji, potentially seriously affecting Tonga's freshwater supply and some crops. Crops will recover more quickly if the volcano does not continue to erupt; otherwise, it will lead to continuous acid rain, which will cause greater damage to water supply and crops.
Global cooling? Not likely
Many people are worried that such a violent volcanic eruption will affect global temperatures. In this regard, according to Cronin's analysis, most of the volcanic plumes generated by the volcanic eruption in Tonga are located in the lower troposphere or atmosphere, the eruption time is also short, and there is not much aerosol to reflect sunlight, which is less likely to cause global cooling.
This is Hong Aha Apai Island in Tonga taken on November 4, 2015 (file photo). Xinhua News Agency (Photo by Cronin)
Xu Zhiyang, a meteorologist and climatologist at Singapore's New Leap University of Social Sciences, believes that after the eruption of Mount Pinatubo in the Philippines that year, the earth's surface temperature dropped by about 0.6 degrees Celsius. The eruption of Tonga volcano is large, but the eruption of sulfur dioxide and other substances is far less than the eruption of Pinatubo Volcano that year, so it will not have a substantial impact on the global climate in the long run.
Mount Pinatubo in the Philippines erupted twice on June 9 and 15, 1991, releasing massive amounts of smoke mixed with rubble and soaring into the sky. Xinhua News Agency
(Reporters: Lu Huaiqian, Guo Lei, Hao Yalin, Wang Lili, Zhao Xiaona, Guo Shuang; Reporters: Chen Zheng'an, Larry Nilder; Editors: Wang Pei; Editors: Ma Xiaoyan, Sun Hao)
Co-produced by the International Department of Xinhua News Agency
Produced by Xinhua News Agency's International Communication Integration Platform