Seismic belts of the Earth. Names of Earth's seismic belts
Seismic belts of the Earth are zones wherethe lithospheric plates, of which our planet is composed, touch each other. The main characteristic of such areas is increased mobility, which can be expressed in frequent earthquakes, as well as in the presence of active volcanoes, which from time to time have the property of erupting. As a rule, similar areas of the Earth stretch for thousands of miles in length. Throughout this distance can be traced a large fracture of the earth's crust. If such a ridge is at the bottom of the ocean, it looks like a mid-oceanic trough.
Modern names of seismic belts of the Earth
According to the generally accepted geographical theory, nowadayson the planet there are two largest seismic belts. These include one latitudinal, that is, located along the equator, and the second - meridian, respectively, perpendicular to the previous one. The first is called the Mediterranean-Trans-Asian, and it originates in the Persian Gulf, and the extreme point reaches the middle of the Atlantic Ocean. The second is called the Pacific Pacific, and it passes in full accordance with its name. It is in these areas that the greatest seismic activity is observed. There are mountainous formations here, as well as permanent volcanoes. If these seismic zones of the Earth are viewed on a world map, then it becomes clear that most of the eruptions fall on the underwater part of our planet.
The largest ridge in the world
It is important to know that 80 percent of all earthquakesand volcanic eruptions fall precisely on the Pacific ridge. Most of it is located under salt water, but it also affects some parts of the land. For example, in the Hawaiian Islands, it is because of the split in the earth that earthquakes are constantly occurring, which often lead to a large number of human casualties. Further this giant ridge includes the smaller earthquake belts of the Earth. So, Kamchatka, the Aleutian Islands belong to it. It affects the west coast of the entire American continent and ends as much on the South Antilles Loop. That is why all the residential regions that are located along this line are constantly experiencing more or less strong earthquakes. Among the most popular giants, which is located in this volatile area is Los Angeles.
Seismic belts of the earth. The names of less common ones
Now consider the zones of so-called secondaryearthquakes, or secondary seismicity. All of them are quite densely located within our planet, but in some places echoes are not audible at all, while in other regions the tremors reach almost the maximum. But it is worth noting that this situation is inherent only in those lands that are under the waters of the World Ocean. The secondary seismic belts of the Earth are concentrated in the waters of the Atlantic, in the basin of the Pacific Ocean, as well as in the Arctic and in some areas of the Indian Ocean. It is interesting that strong shocks, as a rule, fall precisely on the eastern part of all terrestrial waters, that is, the "Earth breathes" in the Philippines, gradually descending to Antarctica. To some extent, the pockets of these blows spread to the waters of the Pacific Ocean, but in the Atlantic it is almost always calm.
A more detailed consideration of this issue
As was mentioned above, the earth's seismic beltsare formed precisely at the junction of the largest lithospheric plates. The largest of these is the meridian Pacific Ridge, on the entire length of which there are a huge number of mountain elevations. As a rule, the focus of blows, which causes tremors in this natural zone is subcrustal, so they spread very long distances. The most seismically active branch of the meridian ridge is its northern part. There are very high impacts, which often reach the California coast. It is for this reason that the number of skyscrapers that is being built in this area is always reduced to a minimum. Note that cities such as San Francisco, Los Angeles, in general, one-story. High-rise buildings are built only in the city center. Going lower, to the south, the seismicity of this branch is reduced. On the west coast of South America, the tremors are no longer as strong as in the North, but there are still subcortical foci there.
Many branches of one large ridge
The names of the Earth's seismic belts, whichare offshoots from the main meridian Pacific Ridge, are directly related to their geographic location. One of the branches is the Eastern one. It originates off the coast of Kamchatka, runs along the Aleutian Islands, then it traverses the entire American continent and ends on the Falkland Islands. This zone is not catastrophically seismic, and the tremors that form within it are small. It should be noted that the branch to the East is leaving the equator from it. The Caribbean Sea and all the island states that are located here are already in the zone of the Antilles seismic loop. In this region there have been many earthquakes that brought many disasters, but now the Earth has "calmed down", and the tremors that are heard and felt in all the resorts of the Caribbean Sea do not pose any danger to life.
A small geographic paradox
If we consider the Earth's seismic belts onmap, it turns out that the eastern branch of the Pacific ridge runs along the westernmost coast of our planet's land, that is, along America. The western branch of the same seismic belt begins at the Kuril Islands, passes through Japan, and then divides into two others. It is strange that the names for these seismic zones were chosen with accuracy and vice versa. By the way, those two branches to which this strip is divided also have the names "Western" and Eastern ", but this time their geographic affinity coincides with generally accepted rules. Eastern leaves New Guinea for New Zealand. In this area, there are strong enough tremors, often devastating. The eastern branch covers the coasts of the Philippine Islands, the southern islands of Thailand, as well as Burma, and finally connects with the Mediterranean-Trans-Asian belt.
Overview of the "parallel" seismic ridge
Now let us consider that lithosphere region, whichis located closer to our region. As you have already understood, the name of the seismic belts of our planet depends on their location, and in this case the Mediterranean-Trans-Asian ridge is the confirmation. Within its length are the Alps, Carpathians, Apennines and islands located in the Mediterranean Sea. The largest seismic activity occurs at the Romanian site, where strong tremors are often observed. Moving to the East, this belt captures the lands of Baluchistan, Iran and ends in Burma. However, the total percentage of seismic activity, which falls on this area, is only 15. Therefore, this region is quite safe and quiet.