Why do earthquakes occur frequently in Chile? Nature of chile
In most cases, people do not think about the essence of geological processes, and the reason for earthquakes is called features of mountainous terrain. However, the mere presence of mountains does not become an indispensable sign of seismic activity. Why do earthquakes occur frequently in Chile? Is it only because of the long ridge that stretches along the entire Pacific coast? In fact, experts point to a combination of causes, among which the Andes are not the main culprits of natural disasters.
Features of geographical location
If we consider the foothills in general, as one of the factors of a possible seismic hazard, then of all the countries of South America, it is Chile that is located literally on the front line of the disaster front. The country is literally flattened along the southern part of the Cordillera mountain belt. Andes belong to the so-called revived mountains.That is, here once upon a time there were mountains that were formed in the Jurassic period of the Mesozoic era, and due to natural processes grew old. The Andes are now experiencing a resurgence of seismic activity, and turbulent geological processes can already serve as an explanation for why earthquakes occur frequently in Chile. However, experts believe that this is only a consequence of a more global phenomenon.
Movement of lithospheric plates
The main cause of all earthquakes in this part of the globe is the junction of the massive South American continental plate and the Nazca oceanic plate. These two plates touch off the coast of Chile, forming a deep-sea Atakam Trench, also called the Peruvian-Chilean.
Why do earthquakes occur frequently in Chile? This can be briefly explained by the phenomenon of subduction. This is the friction of two areas of the earth's crust, during which the Nazca plate is shifted under the South American Plate. The subduction zone is unstable, because the edge sinking deep into the slab penetrates the mantle, while destabilizing the state of the upper slab.The vast majority of earthquakes recorded in Chile originate in the Peruvian-Chilean trench, up to a hundred kilometers from the coast.
Pacific Ring of Fire
If you look at the Pacific Ocean, you can see how it is surrounded by a kind of seismically active circle, which conventionally begins in the south of Chile, stretches along the entire western coast of the American continents, in the north in a smooth arc passes through the Kamchatka Peninsula through Japan and further south. This area is called the Pacific Ring of Fire, despite some of the stability zones that it has in the New Zealand region and along the Antarctic coast. This fact also explains why earthquakes occur frequently in Chile.
Ring subduction of the lithospheric plates of the Pacific Ocean creates conditions in which an earthquake off the coast of Chile rolls to the shores of Japan, and the same happens in the opposite direction. With the largest cataclysms, sensitive echoes reached California, despite the great distance. It turns out that a sufficiently strong seismic activity at any point in the Pacific Ring of Fire can cause damage to any country that is in this dangerous “community”.
Chile's worst earthquake
The strongest of the recorded earthquakes occurred on May 22, 1960, and was called the “Great Chilean Earthquake”. In terms of power and consequences, this was the most severe seismic cataclysm among the documented seismic observations in the entire history. The main push with a magnitude of 9.5 on the Kanamori scale occurred in the vicinity of the city of Valdivia, and provoked a chain of aftershocks and a cascade of weaker earthquakes throughout Chile.
Surviving witnesses argued that the earth was waving like water, and even on all fours it was difficult to stay in place. The impulses provoked several tsunamis up to 10 meters high, and it was they who caused even more terrible destruction and a huge number of victims. After the tremors, the tsunami swept across the ocean and hit the shores of California and Japan. Given the distances, this alone indicates a powerful tectonic shift. If we analyze why earthquakes occur frequently in Chile, and whether the termination of these cataclysms is possible, then this is definitely friction of lithospheric plates, and there is no reason to expect the situation to stabilize in the coming decades.
Nature and steadily high seismic activity
Due to its geological and geographical features, Chile’s nature is incredibly diverse. In the northern part of the country there is the unique and the driest Atacama desert in the world, lush subtropics in the center and in the south, and alpine tundra extending to glaciers extends to the highlands. Seismic activity, of course, seriously affects the nature, soil composition. There is a high risk of salinization of agricultural land as a result of tsunamis or tectonic emissions.
A question from the school curriculum in preparation for the OGE “Why earthquakes occur frequently in Chile” implies that it is necessary not only to name the cause, but also to outline the consequences for natural resources and the economy.
The young and revived mountains are a stock of all kinds of minerals. In the Andes there are large reserves of rare metals, and in terms of reserves of nitrate and copper, Chile is in the first place in the world, and is also among the leaders in reserves of sulfur and molybdenum. Despite the high economic potential and the significant pace of development of the country, seismic activity imposes its limitations on the possibility of developing fields.Most likely, local residents also wonder why earthquakes occur in Chile, and would prefer to get rid of this phenomenon altogether.
Due to tectonic shifts and the constant risk of collapses and tsunamis, for any economic activity, additional funds have to be invested in the latest earthquake-resistant technologies, the development of new warning systems and evacuation, and additional energy security. As a result, the cost of any product or mined ore inevitably increases. In Chile, economic growth was maintained largely due to turnover, an increase in the volume of mining. Modern developments allow to revise this approach and increase production with an additional margin of safety.