Scientist A. Spiridonov told the portal about how this huge explosion took place, what its further consequences could be and what volcanoes could cause. 15min.
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This volcano in the Pacific Ocean is about a couple of feet high and 20 km wide. “It’s a huge underwater mountain,” says Spiridonov.
Scientists estimate that the explosion that erupted on January 14 after a volcano erupted between Hunga Tonga and Hunga Ha’apai Islands is the largest explosion in at least 30 years and probably one of the most powerful in 150 years, Spiridonov said.
It is a huge underwater mountain.
“The islands of Hunga Tonga and Hunga Ha’apai are on the edge of the so-called caldera. The caldera is a collapsing structure. The volcano grows and then when the magma chamber runs out, it collapses inwards. These islands are the fringes of that collapse, ”says the geologist.
What happened in Tonga is a freatomagmatic explosion that occurs when water enters a magma chamber that heats up in it and transitions to a supercritical state. An explosion occurs if the camera limit is not maintained.
“As far as history has been concerned, this is the most powerful vapor explosion,” says a VU geologist.
The volcano announced itself
It has long been thought that this volcano is inactive, but, as A. Spiridonov says, the activity or inactivity of a volcano is very conditional.
This is the most powerful vapor explosion
“If the volcano does not erupt, it is good that no processes are taking place in it,” says the scientist.
According to him, the volcano was not actively erupting until 2012, and since 2012. the situation began to change somewhat. The two islands of Tonga – Hunga Tonga and Hunga Ha’apai – merge through a gap in which a pyroclastic cone consisting of volcanic emissions has grown for nearly a decade.
“It is thought that as it grew, cracks formed in the water, which penetrated the magma chamber in the volcano. In this way, the activity of the volcano has been increasing over the course of the year, ”says A. Spiridonov.
According to the scientist, the volcano has been active for a decade and nothing dramatic has happened during it. The volcanic eruption was not predicted.
The volcano itself warned.
“It simply came to our notice then. But there were signs that an eruption was taking place, everyone knew there was no need to be there. The volcano itself warned, beginning to let in huge clouds that appeared menacing enough. The nearest settlements are a few tens of kilometers away, so no one comes to him, ”he says.
How did the explosion happen?
“It is believed that magma began to accumulate somewhere at a depth of five kilometers, went up the canals, formed pyroclastic cones, and then entered the magmatic chamber through cracks and canals of water. “The critical pressure has risen, the pyroclastic cone has ruptured, water has dripped down and an explosion has taken place,” says the scientist.
The eruption of the Tonga volcano has also been captured in photographs, but, according to a VU scientist, it does not really depict the big one.
“There are only prelude images taken a few days before. If people had been close to him during the real, big explosion, he would have taken them away, torn them to shreds, “says the scientist.
Tsunamis in such cases are rare, but this time there was a big one
Spiridonov says it is believed that a landslide occurred during the eruption of the volcano, which gave impetus to the tsunami.
“There are usually no tsunamis when volcanoes erupt. Tsunamis occur when a volcanic eruption occurs and that mass falls into the water, displaces the water and forms a huge wave, ”says the scientist.
The scientist points out that absolutely all coasts around the Pacific Ocean are at risk of a tsunami, so tsunami warning sensors warn residents in nearby countries of the need to go higher.
However, the tsunami claimed several lives. The tsunami in Tonga killed three people, including a British citizen, and killed two more before the waves in Peru.
“It simply came to our notice then that there was a tsunami just two meters high. While two meters is also a huge force: imagine the sea level rises two meters before your eyes and that sea starts flowing thirty to fifty kilometers an hour. You suddenly find yourself in the middle of a mountain river and that river flows into you. Then even two meters is very much. And in Tonga, it has been estimated that the local tsunami could have risen to as much as 15 meters. These are waves the size of a five-story house. Some places there are just swept away, “says A. Spiridonov.
It is believed that Tongoskalni has now released most of its energy, but the same explosion may have shaken the Earth’s mass, so there may continue to be remote areas that could cause another tsunami. However, it is thought that if there is another tsunami, it will not be as big as the initial tsunami, says a VU researcher.
The shock wave sank three times over the world
The surge in water waves caused by the eruption of the Tonga volcano was felt even in remote Alaska, and here the shock wave sank three times over the world. It is also recorded in Lithuania.
It is a physical event on a planetary scale. Our atmosphere shook like a bell on the planet.
The shock wave was recorded by barometers by meteorologists. According to A. Spiridonov, it has become apparent in Lithuania that the atmospheric pressure has increased by a hundredth since the wave.
“Interestingly, that wave was so strong that its waves traveled around the globe and near Algeria, which is the antipode of Tonga (in the opposite part of the world from Tonga), reflected and swept in the opposite direction again, in Vilnius again, then it was discussed at Hunga Tonga again, it was reflected again, it went again and it was noticed again in Lithuania. The wave was then captured three times.
It is a physical event on a planetary scale. “Our atmosphere vibrated like a bell on the planet,” says a scientist.
Could it save me from rapid climate change?
According to A. Spiridonov, the main mechanisms of action of these explosions are ash and aerosols, as well as various gases.
“The most important of these are SO2, sulfur oxides that, when entering the stratosphere, reflect the sun’s rays and can cool the climate,” says the geologist.
However, it is estimated that a relatively small amount of sulfur oxide was released into the atmosphere after the eruption of the Tonga volcano – about 400,000. tons.
Here is the 1991 the eruption of the Pinatubo volcano in the Philippines emitted 20 million tons of sulfur oxide. As a result, the global climate has cooled by as much as 0.7 degrees in two years, but there have also been stronger blizzards in the world, with extreme weather.
“In the case of Tonga, it is estimated that little of this gas has been released into the atmosphere and we are unlikely to have a small ice age. But it is possible that in the southern hemisphere it will be possible to admire beautiful sunsets red due to aerosols for some time, ”says the scientist.
There are benefits, but it also does harm
Although volcanic eruptions could slow down the planet’s heat, it would come at a cost.
“The problem with volcanoes is that their sulfur oxide aerosols quickly fall back into the soil or into the ocean. The effects may be severe, but they are short-lived. If there were an eruption to offset our CO2 emissions, that offset would take three years. The volcano should be blown up very hard every three years. It is not clear how the Earth system would react if it were constantly pushing and pushing, ”says A. Spiridonov.
According to the scientist, sulfur oxide falls out more than the CO2 removed. The lifetime of carbon in the atmosphere is calculated from tens of years to 2 years, and SO only in years.
It is not clear to what extent such an intervention would have a global impact, perhaps exacerbating everything.
“There are geoengineering ideas that might allow planes to emit SO2 into the stratosphere. The bottom line, however, is that ten million tonnes of sulfur oxides would be released into the atmosphere each year to offset carbon emissions, which later turn into sulfuric acid and fall on our heads and poison us. It is not clear to what extent such an intervention would have a global effect, perhaps it would make things much worse, ”says the VU researcher.
Unless a volcano that is low in carbon dioxide, low in sulfur oxide and scattered in the tropics could stop global warming with less dangerous consequences.
“This ash decomposes and absorbs CO2 very quickly, and such a mechanism would be able to produce climate change. But that absorption would still take a very long time – centuries, “A. Spiridonov assures.