Wang Taitung Stone Ancient Volcano.
Breccia formed by volcanic eruptions on Lingshan Island.
On January 14, a massive eruption of submarine volcanoes in the South Pacific island nation of Tonga had a huge impact on the region and triggered a strong tsunami that affected Pacific rim countries such as Australia, New Zealand, Japan and the United States. For a time, the animated pictures and videos of the volcanic eruption brushed the circle of friends, and everyone intuitively felt a "roar" of the earth. As the undersea volcanic eruption in Tonga continues to ferment, many citizens also have concerns and concerns. What impact will this eruption have on us? Will there be changes to the future climate? Yesterday, the reporter contacted experts in relevant majors of Qingdao's many universities in Qingdao to bring the relevant follow-up to the volcanic eruption.
There are many extinct volcanoes around Qingdao
Many old Qingdao know that in Qingdao, there is a volcanic island, where the scenery is beautiful, and it is still a good place to fish in the sea. That's right, Bamboo Fork Island. Zhucha Island is a volcanic island, and there is still a relatively complete volcanic crater on the island. Similar to Zhucha Island, Lingshan Island and Saitang Island also have a common feature, the island is surrounded by volcanic rock, just like pouring down from the sky, deformed and different, looking crisp, hard texture.
"The West Coast Wangtai Dongshi Scenic Area, the Jimoma Mountain Geopark, and some islands near Jiaozhou Bay all have ancient volcanoes, and some of them still retain intact craters." Ni Jinlong, an associate professor at the School of Earth Sciences and Engineering of Shandong University of Science and Technology, said that these ancient volcanoes (extinct volcanoes) were formed 100 million years ago, and the earth was in the Cretaceous era, which was also a period of dinosaur prosperity. It is understood that 100 million years ago, the earth's crust in North China underwent strong cracking, including Qingdao, Gaomi, Laiyang, Zhucheng and other places, there were strong volcanic eruptions, forming thick volcanic rocks on the surface.
The broad continental shelf weakens tsunami waves
"Will this volcanic eruption in Tonga affect us? "Recently, with the continuous fermentation of the volcanic eruption in Tonga, citizens in coastal cities have raised relevant questions. To this end, Wang Nan, a lecturer at the School of Oceanography and Atmosphere of the Ocean University of China, said: "The tsunami generated by the volcanic eruption in Tonga hit the countries along the Pacific coast, but the continent is far from Tonga in the South Pacific, and the continent has a very wide continental shelf, which can effectively weaken the energy of the tsunami wave, and the wave height of the tsunami wave monitored in the coastal areas of the mainland generally does not exceed 20 cm, so the tsunami caused by the volcanic eruption of Tonga will not bring us a catastrophic impact." ”
Why did the Tonga volcano "thunder" this time? Wang Nan said, "Tonga Volcano is at the junction of the Indo-Australian Plate and the Pacific Plate, and the tonga trench on its east side can reach a maximum depth of 10,882 meters, which belongs to the typical active continental edge island arc volcanic system, and when the Pacific plate subducts under the Indo-Australian Plate in the depths of the trench, the accompanying earthquakes and volcanic activity will occur frequently." In addition, there may be mantle columns and magma chambers in the lower part of the Tonga volcano, which are also the source of material energy for the deep earth where volcanic eruptions may occur. Based on this tectonic environment and the history of periodic eruptions of Tonga volcanoes, the volcano will most likely continue to erupt multiple times, lasting from weeks to months. ”
Although the tsunami caused by the volcanic eruption in Tonga has no catastrophic impact on the mainland, Wang Nan said that continuous volcanic eruptions produce large amounts of volcanic ash and harmful gases, which can block solar radiation or affect atmospheric circulation and produce cooling, and can also produce large amounts of aerosols to cause rainfall. Current volcanic eruptions are still relatively small in relative history and may have a large impact on the local climate of the Southern Hemisphere, with limited impact on the Northern Hemisphere and the global climate. Subsequent international monitoring of the frequency, intensity and duration of eruptions of Tonga volcanoes will continue to be monitored internationally, and whether they can have an impact on the continental or global climate will ultimately be calculated according to the volume of the eruptions.
Qingdao's geological structure environment is stable
"Because the continental coastal zone is not at the boundary of large plates, it is located on the edge of a passive continent, the continental shelf is wide, the plate tectonic movement is relatively stable, and the earthquake mainly comes from the local tectonic movement inside the plate, usually with low frequency and small magnitude." Therefore, there is no such frequent volcanic and seismic activity as Japan and Tonga in the coastal areas of the mainland, and everyone can rest assured. In addition, Wang Nan also said that the state will set the elevation level zero point in Qingdao, but also because the local geological structure environment in Qingdao is stable, and the uplift and decline of the earth's crust are not obvious, which is conducive to the long-term stability of the elevation benchmark.
"For a long time, many citizens have misunderstood the 'hot springs' and 'seismic belts'. Ni Jinlong said that there is no necessary connection between "hot springs" and "seismic belts". There are many hot springs in Qingdao Jimo District because Jimo is on the Muping-Jimo fault zone, which extends along Jimo to Muping City in the north of the peninsula, and due to the large depth of the fracture cutting crust, hot water in the deep part of the crust flows out along the fault zone where the surface pressure is low.
Related developments
Ministry of Foreign Affairs: There are no reports of casualties among Chinese citizens in Tonga
Foreign Ministry spokesman Zhao Lijian said at a regular press conference on the same day on the 18th that on the afternoon of the 17th, the Consular Department of the Ministry of Foreign Affairs live-linked the Embassy in Tonga to learn about the latest situation of local Chinese citizens, and there are no reports of Casualties of Chinese citizens.
Zhao Lijian said that earlier, the Chinese Embassy in Tonga assisted a resident in Guangdong to contact his relatives in Tonga who had lost contact due to communication interruptions and confirmed that they were safe and sound. The embassy also called Shandong Liaocheng University via satellite phone to inform it that all three of its teachers were safe.
"The Ministry of Foreign Affairs and the Embassy in Tonga will continue to pay close attention to the situation of Chinese citizens in Tonga and provide consular protection and assistance in a timely manner." At the same time, we also remind Chinese citizens in Tonga and neighboring countries to pay close attention to the relevant early warning information of the host country and strengthen security precautions. Zhao Lijian said.
In view of the serious disasters, shortage of materials and difficulties in people's lives in Tonga, Zhao Lijian said that china is very concerned about the practical difficulties caused by the volcanic eruption in Tonga to the production and life of the people in Tonga, and feels the same way. He said that in order to help the Tongan government and people tide over the difficulties, the Chinese side will, at the request of the Tongan side, provide assistance to a batch of emergency supplies such as drinking water, food, personal protective equipment, disaster relief equipment, etc., and arrive as soon as the local airport resumes operations and the flight conditions permit. According to Xinhua News Agency
Science
How to influence La Niña is controversial
Experts say the location of the Tonga volcano eruption is very special, located on the south side of the el-La Niña phenomenon key monitoring sea area. The National Climate Center also said that volcanic eruptions will affect the current trend of La Niña's state through sea-air interaction.
But how it will be affected remains controversial. Data suggest that since 1882, four-fifths of volcanoes have experienced El Niño-like situations after eruptions, but the sample size makes it difficult to explain. Some scientists have also shown that volcanic eruptions at different locations in different SST states lead to different effects. For example, in neutral states (neither El Niño nor La Niña), volcanic eruptions will develop into An El Niño; under El Niño conditions, El Niño will be maintained after a volcanic eruption; and in La Niña conditions, especially after volcanic eruptions in the Southern Hemisphere, la Niña is readily maintained.
Zhou Bing, chief expert of the National Climate Center, said that volcanic eruptions, especially in the central Pacific island country of Tonga, have different academic views on the connection with El Niño-La Niña, and consistent conclusions have not yet been formed.
Affecting the climate? It is too early to draw conclusions
In most of our minds, the crater is like Mount Fuji or Mount Changbai in Japan, and only the small circle at the top of the mountain is the crater. But in fact, the crater is huge... Therefore, the power of this volcanic eruption is particularly powerful. And it's not just Tonga that is facing disaster this time. The tsunami caused by the volcanic eruption has swept across the Pacific Ocean from east to west and from south to north.
Although the mainland is far from Tonga, experts say that atmospheric circulation connects the world into a whole, involving the whole body. So will this eruption cause a change in the global climate? Experts say it is too early to draw conclusions, there are still uncertainties about the volcanic eruption in Tonga, and the most important point is that the level of the volcanic eruption in Tonga cannot be determined. 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 volcanic eruption, and it is impossible for volcanologists to give the volcanic eruption level in a short period of time. The internationally common indicator for judging the size of volcanic eruptions is called the volcanic eruption index (VEI for short), which is a comprehensive measure of the intensity of volcanic eruptions 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, which is divided into 8 levels. For now, the energy of the Tonga volcano is far less than that of the 1815 Tambora eruption (VEI7 level), and its short-term weather impact may be relatively obvious, and it is difficult to make conclusions in a short time as for the climate impact.
This edition is written by Guanhai News/Qingdao Morning Post reporter Zhong Shanglei The photo is provided by the interviewee