Earth's seismic belts are zones where lithospheric plates that make up our planet are in contact. 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 tend to erupt. Typically, such areas of the Earth stretch for thousands of miles in length. Throughout this distance, a large fracture of the earth's crust can be traced . If such a ridge is located at the bottom of the ocean, it looks like a mid-ocean trench.
Modern names of Earth's seismic belts
According to generally accepted geographical theory, now there are two largest seismic belts on the planet. They include one latitudinal, that is, located along the equator, and the second is the meridian, respectively, perpendicular to the previous one. The first is called the Mediterranean-Trans-Asian and it originates approximately in the Persian Gulf, and the extreme point reaches the middle of the Atlantic Ocean. The second is called the meridional Pacific, and it passes in full accordance with its name. It is in these areas that the highest seismic activity is observed. Here mountain formations, as well as permanent volcanoes, have their place . If you look at these seismic zones of the Earth on a world map, it becomes clear that most of the eruptions occur precisely on the underwater part of our planet.
The largest ridge in the world
It is important to know that 80 percent of all earthquakes and volcanic eruptions occur precisely in the Pacific mountain range. Most of it is located under salty waters, but it affects some parts of the land. For example, in the Hawaiian Islands, precisely because of the split of the earth's rock, earthquakes constantly occur, which often lead to a large number of human casualties. Further, this giant ridge includes the Earth's smaller seismic belts. So, Kamchatka, the Aleutian islands belong to it . It affects the western coast of the entire American continent and ends already 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 earth tremors. Among the most popular giant cities located in this volatile area is Los Angeles.
Seismic belts of the earth. Names of less common ones
Now consider the zones of the so-called secondary earthquakes, or secondary seismicity. All of them are quite densely located within our planet, but in some places the echoes are not heard at all, while in other regions the tremors reach almost the maximum. But it is worth noting that this situation is inherent only to those lands that are under the waters of the oceans. Secondary seismic zones of the Earth are concentrated in the waters of the Atlantic, in the Pacific Ocean basin, as well as in the Arctic and in some parts of the Indian Ocean. It is interesting that strong shocks, as a rule, fall on the eastern part of all earthly waters, that is, the “Earth breathes” in the Philippines, gradually descending to Antarctica. To some extent, the centers of these attacks extend to the waters of the Pacific Ocean, but in the Atlantic it is almost always calm.
A more detailed discussion of this issue
As mentioned above, Earth's seismic belts are formed precisely at the junctions of the largest lithospheric plates. The largest among these is the Pacific meridian ridge, along the entire length of which there are a huge number of mountain elevations. As a rule, the source of impacts, which causes shocks in this natural zone, is subcrustal, therefore they spread over very large distances. The most seismically active branch of the meridian ridge is its northern part. Extremely high impacts are observed here, which often reach the California coast. For this reason, the number of skyscrapers that are being built in this area is always minimized. Please note that cities such as San Francisco, Los Angeles, in general, are single-story. High-rise buildings are erected only in the city center. Heading lower to the south, the seismicity of this branch is reduced. On the western coast of South America, the tremors are not as strong as in the North, but subcortical foci are still noted there.
Many branches of one large ridge
The names of the Earth's seismic belts, which are branches from the main meridian Pacific ridge, are directly related to their geographical location. One of the branches is East. It originates off the coast of Kamchatka, runs along the Aleutian Islands, then goes around the entire American continent and ends on the Falkland Islands. This zone is not catastrophically seismic, and the shocks that form within it are small. It should only be noted that in the equator region, a branch to the East leaves from it. The Caribbean Sea and all the island states that are located here are already in the Antilles seismic loop zone. In this region, many earthquakes were previously observed, which brought a lot of disasters, but in our days the Earth has "calmed down", and the tremors that are heard and felt in all resorts of the Caribbean Sea do not pose any danger to life.
A small geographic paradox
If we look at the Earth's seismic belts on a map, it turns out that the eastern branch of the Pacific Ridge runs along the westernmost coast of the land of our planet, that is, along America. The western branch of the same seismic belt begins at the Kuril Islands, passes through Japan, and then is divided into two others. It is strange that the names of these seismic zones were chosen exactly the exact opposite. By the way, those two branches into which this band is divided also have the names “Western” and “Eastern”, but this time their geographical affiliation coincides with generally accepted rules. Eastern leaves through New Guinea to New Zealand. Quite strong tremors can be traced in this area, often destructive. The eastern branch covers the shores of the Philippine Islands, the southern islands of Thailand, as well as Burma, and finally connects to the Mediterranean-Trans-Asian belt.
A brief overview of the “parallel” seismic ridge
Now consider the lithospheric region, which is located closer to our region. As you 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 proof of this. Within its length are the Alps, Carpathians, Apennines and islands located in the Mediterranean Sea. The greatest seismic activity occurs at the Romanian site, where quite often strong shocks are observed. Moving east, this belt captures the lands of Balochistan, Iran and ends in Burma. However, the total percentage of seismic activity that falls on this area is only 15. Therefore, this region is quite safe and calm.