What is the impact of the volcanic eruption in Tonga? Hear what the experts have to say

Beijing, 19 Jan (Xinhua) -- A violent undersea volcanic eruptions have recently occurred on Hong Aha Apai Island in The South Pacific island nation of Tonga, triggering a tsunami. Could such a massive volcanic eruption affect the global climate and cause global cooling? What is the impact on the mainland?

On January 14, a volcanic eruption began on The island of Hon Aha Apay, about 65 kilometers north of The Cowua Lofa, the capital of Tonga, and erupted again on the 15th. Volcanic eruptions cause large amounts of ash, gas and water vapor to enter the sky to form huge clouds, which erupt to a height of 20 kilometers. According to the analysis of multiple experts in Australia and New Zealand, this may be the world's largest submarine volcanic eruption in 30 years.

Hu Xiao, chief weather analyst of the China Weather Network, said that in 1815, Mount Tambora in Indonesia erupted, and as much as 1.5 million cubic kilometers of dust and rocks were thrown into the air, resulting in significant cold weather in the United States in 1816, rare heavy rain in Western Europe, a significant drop in temperature in the southern part of the continent, and an abnormal cold climate that froze trees and rice to death, leading to famine. Some scholars believe that this is due to the extreme events of the climate caused by the eruption of Mount Tambora, and call 1816 the "year without summer".

Dong Hanwen, an associate researcher at the Institute of Geology of the Chinese Academy of Geological Sciences, said that the internationally common indicator for determining the size of volcanic eruptions is called the Volcanic Explosivity Index (VEI), which is based on the volume of debris ejected by the volcano, the height of volcanic ash exceeding the peak or entering the atmosphere, and the type of volcanic eruption to comprehensively measure the intensity of volcanic eruptions, which is divided into 8 grades.

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)

In general, the size of the volcanic eruption level is controlled by factors such as the total amount and duration of the detritus of the eruption, and it is impossible for volcanologists to give the volcanic eruption level in a short period of time. At present, the eruption index of the Tonga volcano cannot be determined, and the concentration of sulfur dioxide entering the stratosphere caused by the volcanic eruption is not particularly accurately assessed, and it can only be preliminarily speculated that the state of the eruption may not be lower than VEI5, so it is not yet possible to judge the extent of the impact of the eruption on the future climate.

"Judging from the state record of the eruption, the energy of the eruption of the Tonga volcano is far less than that of the Tambora eruption." Dong Hanwen said, "At present, scientists have begun to calculate data such as sulfur dioxide concentration after the eruption of Tonga volcano to provide reference for future climate change. ”

According to Hu Xiao, the impact of volcanic eruptions on the climate is not decisive on a longer-term scale. Temperature changes from the Xiaoice River climate period from 1500 to 1850 on the mainland can be found, and the continental climate was generally cold from 1790 to 1900. Before the eruption of Mount Tambora in 1815, the continent began to turn significantly colder, and the coldest of this period occurred around 1870. Although the eruption of The Vei7 level of Mount Tambora will significantly change the short-term weather trend, the impact on the climate is not decisive.

Therefore, the volcanic eruption in Tonga may have an impact on short-term weather, and it is too early to draw conclusions as to whether it will affect long-term climate changes.

What impact will this eruption have on the mainland? Dong Hanwen said: "Tonga is located in the southern hemisphere, and the impact on the northern hemisphere is not so fast and not so intuitive. According to the latest monitoring results of the tsunami warning center, the coastal waters of the mainland monitored tsunami waves in the early morning of the 16th, and the maximum tsunami wave amplitude was about 20 centimeters, although the impact was small, but the mainland Hainan, Zhejiang, Fujian and other places still need to strengthen prevention. ”

Source: Xinhua News Agency