The volcanic eruption of Tonga directly led to the loss of contact for many days in the entire territory of Tonga, and many countries issued tsunami warnings. From the satellite cloud map, this submarine volcanic eruption is quite frightening.
The country has suffered an unprecedented disaster. After the tsunami, all houses on one of the country's islands were destroyed, and only two houses survived on another island.
Volcanic eruptions, essentially the same as earthquakes, are a form of outward release of energy from the inside of the Earth's crust, a natural phenomenon. The monitoring of the 1,000-meter-resolution multi-channel true-color composite map produced by our country's Fengyun-4 B satellite data shows that the moment of the eruption of the Tonga volcano, it is as if the earth burps from the mantle and exhales a hot breath.
So how is this energy released?
The structure of the Earth, from the outside to the inside, is the earth's crust, the upper mantle, the lower mantle, the outer core, and the inland core. Among them, the top of the crust and the upper mantle is solid rock, which together constitute the lithosphere, and below the lithosphere, there is an asthenosphere in the upper part of the upper mantle.
The asthenosphere is very hot, reaching 600-1300 degrees, the pressure is 30,000 atmospheres, it is close to the melting point of the rock, the material here is semi-viscous, and the asthenosphere is also the birthplace of magma. Under the action of thermal convection, the material of the asthenosphere can flow slowly,
The movement of the asthenosphere will also drive the movement of the lithosphere. Since the lithosphere is not connected together, but splits into pieces, this is what we call: plates. Driven by the asthelous circle, these plates will move. There will be relative movement between plates and plates, some are squeezed, some are separated, and some are misplaced. As long as three conditions are met at this point:
1, there must be magma at the bottom;
2, there must be a volcanic passage;
3, have the power to make the magma surge.
Then, there is a possibility of volcanic eruptions. The plate and the plate are relatively weak, and it is easier to achieve these three conditions. As a result, the vast majority of volcanoes are located in the Pacific Ring of Volcanic Seismic Zones.
Volcanic eruption rating
In the process of erupting, volcanoes will bring a large amount of material and energy to the ground. Like earthquakes, volcanoes have a total of 8 grades, which are denoted by "VEI", the lowest level is "VEI-1" for the first level, and the highest level is VEI-8 with "VEI-8".
Among them, the fourth level is a sill, beyond which it is a serious volcanic eruption, which releases energy equivalent to an earthquake of magnitude 8.2. In 1902, the Pere Volcano on the Caribbean island of Martinique erupted, which was a Class 4 volcanic eruption, which reduced the entire island to ashes and killed 29,000 people.
A magnitude 5 eruption, releasing energy equivalent to an 8.7-magnitude earthquake, is the fifth magnitude of the famous eruption of Mount Vesuvius in history, which occurred in 79 AD, when volcanic ash and debris flows directly swallowed up two ancient cities of the ancient Roman Empire: Pompeii and Stabbia, killing 3,300 people. The lowest level of the Tonga volcano this time is also 5, and it may even reach 6.
A magnitude 6 volcano erupts, releasing energy equivalent to a magnitude 9.3 earthquake. In 1991, the eruption of Mount Pinatubo on the Philippine island of Luzon fell into this category. At that time, the volcano ejected twenty million tons of sulfur dioxide into the stratosphere, and sulfur dioxide formed aerosol particles in the stratosphere, which could reflect sunlight and thus weaken solar radiation. At the same time, because they are located in the stratosphere, these aerosol particles are not easy to disperse, which, according to the study, has led to a 10% reduction in sunlight on Earth, and the average global temperature has dropped by 0.5 degrees.
A magnitude 7 eruption releases energy equivalent to a magnitude 9.8 earthquake. In 1815, the eruption of Mount Tambora in Indonesia belonged to this category. The eruption killed 50,000 residents and destroyed more than 35,000 homes, dropping global temperatures by an average of 0.53 degrees, and the year 1816 in the entire Northern Hemisphere is known as the Year of No Summer.
So the question is, how serious a magnitude catastrophic is a level 8 eruption?
The eruption of a 8-magnitude volcano, releasing energy equivalent to a 10.2-magnitude earthquake, 74,000 years ago, the eruption of Toba Volcano belongs to this level, and studies have shown that the impact of this volcano almost led to human extinction, and even only 3,000-10,000 people involved in reproduction remained, resulting in a serious population bottleneck for human beings, which greatly reduced human genetic diversity.
There are not many volcanoes most likely to reach a magnitude 8 eruption today, and the Yellowstone Volcano in the United States is one of them, its crater diameter is very large, 2/3 of the entire Yellowstone Park is a crater, because the crater is so large that we can't observe the crater at all.
If There is another Magnitude 8 eruption of Yellowstone, and it is an explosive eruption, then this eruption must cause a large amount of volcanic ash to enter the stratosphere, causing a more severe cooling of the earth, and the impact may last for thousands of years.
The level 8 volcano will definitely affect human beings and cause a great famine in the human world, but whether it will destroy human civilization or even make human beings completely extinct, in fact, it is still quite difficult. After all, human beings are not vegetarians, and will devote all their scientific and technological power to ensure their own safety, even if they are powerless to resist, it is still very difficult to completely extinct billions of people.
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