You know Why Chile is a seismic country ? This South American country is known worldwide for the large number of earthquakes and tremors that are reported every year.
The location of Chile on the planet, together with the Andes Mountains and great volcanic activity make it one of the most seismic places in the world.
Geology of Chile
Chile was formed by the process of orogenesis on the west coast of South America, which corresponds to the border in which two tectonic plates converge: the Nazca plate (oceanic plate) and the South American plate (continental plate).
This border was formed during the Paleozoic and Precambrian periods, where a pure subduction zone was created by microcontinents and old lands.
This subduction gave shape to four important geological features of the zone: the Cordillera de los Andes, the Intermediate Depression, the Cordillera de la Costa and the coastal ditch of Peru and Chile. Chile is in the most active margin of these geological accidents, reason why the volcanic activity is significant.
This, together with the constant collisions of the Nazca, South American and Antarctic plates, make it susceptible to a large number of earthquakes affecting the whole country.
The location of Chile is known as the Pacific Ocean Fire Belt.
One of the most seismic countries in the world
Earthquakes are unpredictable, especially in a country located in the middle of important tectonic plates such as Chile. The plates that are united in its coast, Nazca and South America, are extensive slabs of terrestrial soil and approach to each other in a range of 80 millimeters per year.
Studies indicate that in Chile approximately every 10 years an earthquake occurs with a magnitude greater than 7 degrees in the Richter Scale. This is why more than 100 earthquakes have been reported since the year 1570 to date.
The Nazca plate is the Pacific ocean floor off Chile and is permanently absorbed under the South American plate. That is why the country is the second most seismic in the world - after Japan - with events that affect not only its territory but the entire South Pacific area in the world.
The fault of the Chilean coast is known as a subduction fault and is the same as that found in the coasts of Japan, Alaska and Indonesia, producing some of the most intense earthquakes in the history of the world.
Since the first measurements of earthquakes in Chile, which date back to 1522, dozens of violent earthquakes have been recorded, affecting the town of Valdivia in the south of the country in 1960, the most powerful one recorded with instruments In the world, with a magnitude on the Richter scale of 9.5.
Thousands of people died and several places were completely destroyed, devastated by the earthquake or by the waters of the tsunami that happened minutes later, with waves that reached 10 meters in height.
Another of the biggest earthquakes Chile has experienced was the year 2010, on February 27, with an epicenter in the city of Concepción, also in the south of the country. The magnitude of this event was 8, 8 degrees on the Richter scale and the violent movement destroyed buildings and houses.
On the other hand, the subsequent tsunami devastated several coastal towns such as Iloca and Duao in the south and the archipelago of Juan Fernandez, especially the town of San Juan Bautista, which was completely damaged.
This earthquake, known as 27-F, was so intense that it even modified the geography of the coast, raising the ground more than 4 meters, which was discovered by finding algae and sea shells on the water.
Due to Chile's geographic location on two subduction tectonic plates, which in geology is known as an immersion fault, all of its territory - including its archipelagos of Isla de Pascua, Juan Fernández and Chiloé - are in permanent movement, since The plate of Nazca day after day is introduced under the South American plate.
That is why according to experts, Chile has permanently experienced a series of earthquakes throughout history, which has caused both authorities and the Chilean population to be highly prepared to deal with such disasters.
A country prepared
Chile's infrastructure is one of the best prepared in the world to deal with the earthquakes that constantly affect its territory.
In addition to this there is a preventive system and alerts that circulate in its population. For example, turning on the sirens whenever an earthquake is felt in the coastal cities, so that the population can ascend to higher areas and prevent damage in case of a subsequent tsunami.
On the other hand, building codes must be prepared to withstand an earthquake of magnitude 9 on the Richter scale.
The building may crack and stagger, but should not collapse. This among other security protocols in earthquakes have been adapted and implemented to the local reality of Chile, being widely handled by all its population.
This seismic culture is found not only in the new constructions, but also the old buildings that exist in the north of Chile, as is the case of the use of geometry in the Andean houses, built only with adobe (mixture of mud, straw and Water) due to the scarcity of wood in the area. These houses have a trapezoid form and with this they achieve greater stability in the center of the building.
On the other hand, in Tarapacá, to the north of Chile, another material known as"quincha", very light and malleable to the movements of the earth is used, reason why it does not collapse or collapse in the case of a seismic event of importance .
That is why Chile is considered one of the examples in the world in the management of seismic events.
References
- Geology of Chile. Retrieved from Wikipedia.com.
- Chile's long experience of quakes. Retrieved from news.bbc.co.uk.
- What Caused the Chilean Earthquake? Faults Explained. Retrieved from news.nationalgeographic.com.
- How did Chile manage to survive its recent earthquake virtually unscathed? Retrieved from theguardian.com.
- Why do so many powerful earthquakes happen in Chile? Recovered from quora.com.
- Case study: Vernacular seismic culture in Chile. N. Jorquera Department of Architecture, University of Chile, Santiago, Chile H. Pereira PROTERRA Iberian-American Network and Metropolitan Technological University, Santiago, Chile. Recovered from repositorio.uchile.cl.
- Huge Chilean Earthquake Raised Country's Coast. Retrieved from livescience.com.