How to explain the presence of volcanoes in Japan. Mainland - where there are no volcanoes? In what area are there many of them? The highest and most dangerous volcanoes in the world
Help with geography) What explains the presence of active volcanoes on the territory of Chile? and got the best answer
Answer from Condorita[guru]
The presence of a huge subduction zone (subduction of the oceanic Pacific lithospheric plate under the continental South American plate)
A subduction zone is where the oceanic crust plunges into the mantle. Most earthquakes and many volcanoes are confined to subduction zones.
The geomorphological expression of subduction zones is deep-sea trenches.
Other names for the subduction zone: seismofocal zone, since most deep-focus earthquakes are concentrated in it, or Zavaritsky Benioff Wadati zone, Benioff zone, Wadati zone after the names of the scientists who identified this special zone. The reason for this was seismic data, which showed that earthquake foci are located deeper and deeper in the direction from the deep-sea trench to the continent. The subduction zone is clearly visible on seismic tomographic profiles, at least to the boundary of the upper and lower mantle (670 km).
Two widespread geodynamic settings are associated with subduction zones: Active continental margins and island arcs. In the classical version, a subduction zone occurs when two oceanic or oceanic and continental plates interact. However, in recent decades it has been revealed that during the collision of continental lithospheric plates, one lithospheric plate is also pushed under another; this phenomenon is called continental subduction. Subduction is one of the main geological regimes. With a total length of modern convergent plate boundaries of about 57,000 kilometers, 45,000 of them are subduction, the remaining 12,000 are collision.
Subduction zones are where the most powerful earthquakes and tsunamis occur.
A pile of tectonic plates torn off from a subducting lithospheric plate is called an accretionary prism.
The most famous subduction zones are located in the Pacific Ocean: Japan, the Kuril Islands, Kamchatka, the Aleutian Islands, the coast of North America, the coast of South America. Also subduction zones are Sumatra and Java in Indonesia, the Antilles in the Caribbean Sea, the South Sandwich Islands, New Zealand, etc.
Humanity,usually, does not expect any special favor from nature. Recently, there have been reports of large-scale natural disasters every now and then. Huge areas are flooded with water, hurricanes sweep away entire villages, not to mention earthquakes... However, recently Japan received a pleasant surprise - a volcanic eruption gave the country a new territory!
When at the end of November 2013, 1000 kilometers south of Tokyo, a tiny piece of land appeared, it greatly pleased the Japanese, who were not too spoiled by freedom.
The area where the Ogasawara mountain range is located is known for its seismic activity. The miracle happened thanks to the eruption of an underwater volcano. The “birth” took place in agony. The eruption lasted about two days, and the earthquake managed to affect 30 islands. Fortunately, they all turned out to be uninhabited, and no people were injured...
Interestingly, the border guards discovered the new island by accident. Their attention was attracted by a column of thick smoke from an erupting volcano, the height of which reached 600 meters. This volcanic activity is explained by the fact that the entire territory of Japan is located in the Pacific Ring of Fire - an area along the perimeter of the Pacific Ocean in which most active volcanoes are located.
The Japanese government's response to the replenishment of the archipelago was swift and cautiously optimistic. “If this formation becomes a real island, the area of our territorial waters will increase,” Chief Cabinet Secretary Yoshihide Suga said at a press conference in Tokyo.
Four and a half months passed, and the area of land emerging from the sea had indeed increased considerably. Experts who constantly collect information about this territory claim that since its discovery it has already grown 70 times. According to the latest measurements, the area of the new island in the Ogasawara ridge is more than 700 square kilometers. In addition, during its growth, the “newcomer” connected with the neighboring island of Nishinoshima, also volcanic in origin. As a result, the outline of this formation began to resemble the American cartoon character the dog Snoopy.
The last time an underwater volcano in this area woke up was almost 40 years ago - in 1974. Then, also as a result of the eruption, the island of Nishinoshima appeared... Volcanic activity in this area continues, and it is possible that the newly appeared land area will only grow. According to most researchers, the island most likely will not go under water, as often happens with ocean volcanic formations, and will become part of the territory of Tokyo, since legally the Ogasawara ridge belongs specifically to the Japanese capital.
Now seismologists are putting forward various theories about how the land generated by the volcano will behave in the future. In their opinion, several small lakes are also possible in this area.
The world community, like the Japanese themselves, is more concerned about increasing Japan's resources. After all, growing by the sea, the wealth of the Land of the Rising Sun must inevitably increase. According to international law, waters at a distance of 12 nautical miles (22.2 kilometers) from the coastline of a state are considered its territorial sea, the next 12 nautical miles are the contiguous zone. At a distance of 200 nautical miles (370 kilometers) from the coast, the state’s exclusive economic zone ends and the continental shelf begins, then the open sea. For Japanese fishermen this is additional money, for the state - taxes to the treasury...
However, the Japanese do not live by fish alone. Scientists assume that the new island will be used in the future as a platform for equipment used to search for expensive mineral and energy resources. And minerals are one of the decisive factors of prosperity for any country.
Volcanoes and their features, continents without volcanoes and with a large number of them. The highest and largest volcanoes of the world, Europe, Russia and the USA. The danger of an explosion at the Yellowstone volcano.
Is there a continent without volcanoes?
The question of which continent has no volcanoes may cause confusion. Indeed, these huge mountains, throwing out fire and lava, are found all over the globe. Even in Antarctica, the ice-covered continent, there are several extinct volcanoes! However, scientific facts prove that there is one continent on our planet where there are no volcanoes at all.
Australia is a place where there are no volcanoes. To understand the reason for this, we should remember the nature of such mountains. Volcanoes arise at fault sites, at the boundaries of tectonic plates. In these zones, magma comes closest to the surface and can splash out onto it. And volcanoes in this case serve as a crack in the crust through which magma flows out.
And in Australia there are no active volcanoes precisely because the mainland is located far from faults. Australia is located at the very center of the Australian Plate, and therefore tectonic processes, including volcanism, hardly occur here.
Why are there many volcanoes in Japan?
Japan can be called the antipode of Australia in terms of volcanism. Unlike the calm mainland, the islands of Japan are located in the most dangerous tectonic zone in the world. If Australia lies on one tectonic plate, then Japan is located at the junction of as many as four! The Eurasian, Pacific, North American and Philippine plates converge at this point, creating faults and tectonic belts (see the picture below, Japan is marked with a yellow circle)
It is clear what explains the presence of volcanoes on Japanese territory, but their number is amazing. In total, there are more than 450 fire mountains, 110 of which are active, that is, they erupt frequently. The country's highest point, Fuji, is also a volcano. True, Mount Fuji is considered a dormant volcano because the last eruption here occurred in 1707!
The large number of volcanoes in Japan is closely associated with earthquakes. This region is part of the Ring of Fire tectonic belt. This zone stretches along the circumference of the Pacific Ocean. Earthquakes and volcanic explosions are common here.
What volcanoes are located in Europe?
There are many dangerous, extinct and active volcanoes on the European continent. But only the eruption of some volcanoes became a legend and these events entered world history.
Italian volcano Vesuvius
This famous volcano is located on the territory of modern Italy, near the city of Naples. This is the only active volcano located on continental Europe. The eruption of Vesuvius is quite well known to us from history. It was because of him that in 79 AD the densely populated ancient city of Pompeii was buried under a huge amount of lava and volcanic ash. At the same time, two other ancient cities disappeared from the face of the earth: Herculaneum and Oplontis. This tragedy formed the basis of many paintings and films.
Santorini
This gentle volcano is located on the Greek island of Thira in the Aegean Sea. According to history in 1645-1600 BC. e. There was a powerful volcanic eruption. The volcano rose high above the ground and the eruption was so powerful that its walls collapsed, causing a high tsunami wave of 100 meters to form, which covered the islands. Some scientists believe that it was this eruption that destroyed the Minoan civilization on the island of Crete.
Sicilian Etna
The highest volcano in Europe, Mount Etna, is located on the Italian island of Sicily. Etna is almost 2 times higher than Visuvius. Since this is an active volcano, its height is constantly changing. This volcano erupts on average 3 times a month, and once every 150 years it destroys a neighboring village. The inhabitants of the island adore their volcano, as it is considered not dangerous. After all, by periodically erupting, a volcano cannot accumulate strength and energy for a more destructive eruption. Tourists love to visit this volcano, even during an eruption. If you follow all safety precautions and are not near the crater during an eruption, you can even run away from the erupting lava.
What are the tallest and largest volcanoes in the world?
The largest volcano in the world is a title that Mauna Loa and the Tamu Massif compete for. The first volcano is located in the Hawaiian Islands and is active. The last time Mauna Loa erupted was in 1984. The volume of the volcano is 75,000 cubic km, and the height is 10,168 m! The Tamu Massif is an extinct underwater volcano in the northwest Pacific Ocean. Its volume reaches 2.5 million cubic km, but scientists argue whether this giant can be considered a separate volcano.
Other record holders and simply impressive volcanoes:
- - Mauna Kea is the highest extinct volcano and the mountain with the maximum absolute height. Taking into account the underwater part, this mountain exceeds Everest by almost 2 km, having a height of 10203 m.
- - Llullaillaco is the highest active volcano. This mountain rises in the Andes at 6739 m. The last time an eruption was observed was in 1877.
- - Klyuchevskaya Sopka is a volcano in Kamchatka, the highest active volcano in Eurasia. Its height is 4835 m, and it erupted on April 25, 2016!
- - Erebus - this volcano is located in Antarctica. It is the southernmost such formation, and at the same time constantly operating!
Yellowstone is the most dangerous volcano in the United States
In the USA there is a huge volcano called Yellowstone. This is a caldera - a large round basin left after the collapse of the walls of the volcano. The dimensions of the giant are 55x72 km! Researchers are convinced that Yellowstone will one day explode. The danger of such an explosion lies in the size of the volcano. After the eruption, volcanic ash will cover the atmosphere. This will cause climate change, cooling, acid rain. If the Yellowstone volcano explodes, many species of plants and animals will die. Human existence will also be under threat.
