Written by Liu Jiaqi (Academician of the Chinese Academy of Sciences, Geologist)
The South Pacific island nation of Tonga erupted violently for two consecutive days on January 14 and 15. The Australian Meteorological Agency said on the 15th that it observed a 1.2-meter-high tsunami wave in Nukualoafa, the capital of Tonga. Some media said that the power of the submarine volcano eruption was comparable to the 1,000 atomic bombs of Hiroshima.
On January 15, 2022, local time, an undersea volcano in the South Pacific island country of Tonga erupted on the 14th and erupted again on the 15th. (Source: World Wide Web)
On 16 January, Tonga was in a prolonged "out-of-touch" state due to a total disruption of the Internet and communications networks, unable to report detailed casualty figures. Tsunami warnings were issued by Japan, the United States, Canada, New Zealand, Fiji, Samoa, Vanuatu, Australia and Chile.
Some experts say that the crater has awakened and the eruption period can last for weeks or even years. Such a large volcanic eruption shocked the international community, and some public opinion even feared that "Tonga would sink because of it".
In today's world, the world has gradually understood the mechanism of natural disasters and found ways to prevent some natural disasters. However, in the face of nature's irresistible forces, technology often seems small.
Natural disasters accompany the growth of human civilization
So far, human beings are the only intelligent life on earth, and in the evolution of civilization, human beings are constantly facing the challenges of natural disasters. Because the earth has its own rhythms. Meteorological and geological activity is endless year-round, and other species that share the planet with humans are also multiplying. Natural disasters accompany it, which is what human beings have to endure when they live on earth.
Drought caused by too little precipitation
Primitive humans are almost powerless to resist natural disasters, and forest fires and floods and mudslides can have devastating consequences. But after the fire, human beings discovered the secret of fire and began to use fire to resist the cold, defend themselves and cook food, setting up the first milestone of civilization. Human beings have established civilizations, possessed languages and scripts, and all the history books of civilizations have left records of natural disasters.
Geological activity disasters leave a historical imprint
Among all natural disasters, the Chinese nation has a very deep collective memory of earthquakes. For example, the Tangshan earthquake of July 28, 1976 and the Wenchuan earthquake of May 12, 2008, these powerful earthquakes destroyed a large number of cities and villages, caused heavy casualties to the people in the disaster areas, and also interrupted transportation lines and communication networks, making emergency relief difficulties.
A building that collapsed in an earthquake
Earthquakes are actually the movement of the Earth's crust plates. Most of the world's earthquakes occur at the junction of large plates, and some occur on active faults inside plates. According to the global tectonic plate theory, the Earth's crust can be roughly divided into six plates, namely the Pacific Plate, the Eurasian Plate, the African Plate, the American Plate, the Indian Ocean Plate and the Antarctic Plate. Based on the distribution of these plates, there are three major seismic belts on Earth, namely the Pacific Ring Of Volcanic Seismic Belt, the Mediterranean-Himalayan Seismic Belt, and the Hailing Seismic Belt, the first two of which are related to continents. Therefore, the continent has often experienced earthquakes in history and is still threatened by earthquakes today.
Global Plate Tectonic Map (Image:Wikipedia)
The Pacific Ring of Volcanic Seismic Belt is the main of the three, concentrating about two-thirds of the world's seismic activity, including many active volcanoes. For this reason, this seismic belt is also known as the "volcanic chain". On May 18, 1980, a major eruption occurred at Mount St. Helen in the western state of Washington, releasing the equivalent of 1,600 atomic bombs in Hiroshima, killing 57 people and destroying 200 houses, 27 bridges, 24 kilometers of railroads, and 298 kilometers of highways. The eruption spewed out more than 4.2 cubic kilometers of material, a considerable part of which was shattered by powerful energy.
High-resolution photos of Santa Maria volcano in Guatemala taken by drone
Every time there is a large-scale volcanic activity, especially after a volcanic eruption, huge amounts of volcanic ash can cause serious problems for transportation, energy, sewage treatment and water treatment systems. Volcanic ash caused visibility to drop, sealing off highways and main roads, and closing multiple airports. Volcanic ash can also cause wear and tear on internal combustion engines and some other mechanical equipment and cause short circuits in transformers.
On 24 June 1982, a British Airways Flight B747 flew from the United Kingdom to New Zealand while The Gallungan Volcano on the Indonesian island of Java was active. As the plane passed near the island of Java, it flew into this cloud of volcanic ash. Volcanic ash is sucked into the aircraft engine, rubbing against the high-speed rotating turbofan, causing the temperature inside to rise sharply, and some of the ash is also adsorbed inside the engine. At the same time, the fuel inside the engine is contaminated with volcanic ash, and the failure of poor transportation occurs. The combined effect of these two factors caused all four engines of the aircraft to stop working. Fortunately, as the aircraft lost power and lowered its altitude, the air played a cooling role, and the engine did not start, and the temperature continued to drop rapidly to cause the volcanic ash to fall off. This allowed the plane to restart its engines in the immediate moments before the crash and make a forced landing in Jakarta, Indonesia.
Perhaps the most famous volcanic activity in human history may have been the eruption of Mount Vesuvius in Italy on August 24, 79 AD. The ash completely buried the ancient Roman city of Pompeii, about 10 kilometers from the volcano, and all the people in the city were hidden under the ash. It was not until more than 1,000 years later, from the end of the 16th century to the middle of the 18th century, that sporadic relics were unearthed due to local engineering construction, and people gradually realized that Pompeii, which mysteriously disappeared in the past, was buried underground because of volcanic eruptions. After archaeological excavations and conservation and restoration work, Pompeii has been revived. Various buildings and objects from the Roman period have been preserved, making the entire city ruins a museum that showcases the lifestyle of the Roman period.
Formation of tsunamis
If an earthquake occurs by the sea or in the middle of the sea, the earthquake can also cause a tsunami. Seismic waves will stir up the seawater, and when the huge waves set off by the earthquake approach the coast, because the water depth drops sharply, the seawater carrying huge energy will rise as quickly as a sharp brake, forming a tsunami that engulfs the coast and causes serious damage. On December 26, 2004, a magnitude 9.3 earthquake struck the seabed north of the Indonesian island of Sumatra. It was the second most powerful earthquake ever recorded, causing a strong tsunami that rippled around the Indian Ocean. Because this is the peak tourist season for the Christmas holidays, there are many tourists on vacation on the tropical waterfront. Most of them did not understand the precursors of the tsunami and the methods of escape, so the tsunami caused a total of 292206 deaths.
Manpower can't beat the sky, but it can be prepared
In the history books we can find many accounts of natural disasters, not only earthquakes, but also floods, droughts, locust plagues and severe plagues.
Human activities have the potential to increase the probability of natural disasters in some areas or make them potentially cause more serious losses. Fortunately, humans have discovered the causes of some natural disasters and have found corresponding preventive measures.
Human activities contribute to global warming
However, the operation mechanism of Earth's meteorology is quite complex, and the weather may change unpredictably due to factors that are not yet understood by human beings. There are also some natural disasters, such as earthquakes, which are difficult to predict at the current level of human technology, because humans do not yet know enough about the structure of the earth's depths.
Prediction of earthquakes still has a long way to go
Therefore, the best way to reduce the loss of natural disasters is to carry out targeted prevention in areas where one type or several types of disasters are likely to occur.
However, there are some natural disasters that are difficult for humans to resist with existing technology, and they are often related to astronomical activities. For example, a sudden burst of intense solar activity could wreak havoc on global power networks and computer chips. It would undoubtedly be costly to strengthen global transmission networks and computer systems for such a low probability event, but as long as such an event occurs, it may have a strong impact on contemporary societies that are highly dependent on electrical energy and information technology.
Although human beings have created brilliant civilizations, they cannot overcome the heavens after all. Contempt for the laws of nature's operation, arrogance in trying to "conquer nature", are bound to invite punishment. On the contrary, if we can always be in awe of nature and be prepared for possible disasters, more lives will be saved.
This article is from the book "Meet Science - Academicians and Experts Talk About Science" (all 2 volumes), part of the content from the WeChat public account "Global Network"