Here's a map of where chile is in the world. It is one of the countries that has the most severe earthquakes in the world.
Here are locations of places in Chile where the most severe earthquakes happen. The places are Iquique, San Diego and Valdivia.
Diagrams of the causes of earthquakes
Animation of the causes of earthquakes
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Causes of EarthquakesEarthquakes are vibrations caused by rocks breaking when under stress, the underground surface rock breaks and moves this is called a full plane. Earthquakes are caused by a sudden lateral or vertical movement of rock. The surface where the earthquake starts is called the hypocenter and the surface directly above it is called the epicenter. The earth has four major layers
-Inner core -Outer core -Mantle -Crust The crust and the top of the mantle make up the surface of the earth but this surface is not all in one piece, it is made up of many pieces covering along our surface and slowly move around sliding past each other and bumping into one another. These pieces are called tectonic plates and the edges of these pieces are called plate boundaries. The plate boundaries are the reason earthquakes occur as they are made up of many faults, the edges of the plates are rough and they get stuck while the rest keep moving along. Once the plate has moved far enough the edges unstick and this is when the earthquake occurs. |
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Process of Earthquakes
Studying earth, scientist tell us that the ocean floors and the continents are always moving. And sometimes, this movement is violent and may cause great destruction. The surface of the Earth is not permanent as had been thought. The surface is constantly moving. Continents float on pieces of the Earth’s outer skin, or crust. Crust is created when melted rock pushes up inside the planet. Crust is destroyed when it rolls down into a hot area and melts again. There are 20 of the tectonic plates covering the Earth. The plates float around slowly, some crashing into each other, others movings away from each other and others moving along side each other. The process called plate tectonic is one of the most important revolutions in scientific thoughts as some experts say. The continents move with the plates when they move. Sometimes, the continents split of it is above two plates. Earthquake could be caused by moving tectonic plates. In several places around the Earth, instruments show that around 90% of all earthquakes take place along the lines. After an amount of time, the built up pressure and energy cause huge movement tensions in the plates, and is a massive pressure on the fault lines. And this is when plates move over, against or apart from each other. At this point, there is an earthquake. The escaping energy radiates forward from the fault in all directions in the form of seismic waves. When the waves reach the continents, it affects the ground by shaking and everything on it, destroying buildings and structures. |
Clearing rubble after an earthquake, Tarapaca, Chile
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d Iquique, Chile
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d d Effects on road structure
Chileans doing all they can to support their country.
The effect of earthquakes on buildings and houses diagram. Shows what happens before and during the earthquake.
The Effects on houses
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d d d d d d d d d d d d d d d d d d d How Tsunamis Work- Before, during and after |
Effects of an earthquake
Earthquakes can destroy settlements and kill many people. Aftershocks can cause even more damage to an area. It is possible to state the impacts of an earthquake, by taking the following factors into account: - Short-term (immediate) impacts - Long-term impacts - Social impacts (the impact on people) - Economic impacts (the impact on the wealth of an area) - Environmental impacts (the impact on the landscape) Short Term (Immediate) Impacts Social Impacts- People may be killed or injured. Homes may be destroyed. Transport and communication links may be disrupted. Water pipes may burst and water supplies may be contaminated. Economic Impacts- Shops and business may be destroyed. Looting may take place. The damage to transport and communication links can make trade difficult. Environmental Impacts- The built landscape may be destroyed. Fires can spread due to gas pipe explosions. Fires can damage areas of woodland. Landslides may occur. Tsunamis may cause flooding in coastal areas. Long Term Impact Social Impacts- Disease may spread. People may have to be re-housed, sometimes in refugee camps. Economic Impacts- The cost of rebuilding a settlement is high. Investment in the area may be focused only on repairing the damage caused by the earthquake. Income could be lost. Environmental Impacts- Important natural and human landmarks may be lost. Factors affecting the impact of an earthquake - Distance from the epicentre - the effects of an earthquake are more severe at its centre. - The higher on the Richter scale, the more severe the earthquake is. - Level of development (MEDC or LEDC) - MEDCs are more likely to have the resources and technology for monitoring, prediction and response. - Population density (rural or urban area). The more densely populated an area, the more likely there are to be deaths and casualties. - Communication - accessibility for rescue teams. - Time of day influences whether people are in their homes, at work or travelling. A severe earthquake at rush hour in a densely populated urban area could have devastating effects. - The time of year and climate will influence survival rates and the rate at which disease can spread. Effects are often classified as primary and secondary impacts. Primary effects occur as a direct result of the ground shaking, eg buildings collapsing. Secondary effects occur as a result of the primary effects, eg tsunamis or fires due to ruptured gas mains. When the ground shakes, buildings respond to the to the speed that continually increases, which is transmitted from the ground to the structure of the building. The inactivity of the building can cause shearing to the structure which can cause stresses on the weak walls or joints in the structure resulting in failure or perhaps total collapse. The type of shaking and the frequency of shaking depends on the structure. Tall buildings tend to increase the motions of longer period motions when compared with small buildings. Taller buildings tend to shake longer than small buildings, which can make them cause more harm and damage. Fortunately many tall buildings are constructed to withstand strong winds and some precautions have been taken to reduce their tendency to shake, and they can be made resistant to earthquake vibrations. The effects of a tsunami on a coastline can range from unnoticeable to devastating. The effects of a tsunami depend on the characteristics of the seismic event that generated the tsunami, the distance from its point of origin, its size (magnitude) and, at last, the configuration of the bathymetry (that is the depth of water in oceans) along the coast that the tsunami is approaching. Tsunamis Tsunami is a Japanese term that means "harbor wave". Tsunamis are frequently confused with tidal waves or "seismic sea waves". The term "tidal wave" is misleading, even though a tsunami's impact upon a coastline is dependent upon the tidal level at the time a tsunami strikes, tsunamis are unrelated to the tides. (Tides result from the gravitational influences of the moon, sun, and planets.) The term "seismic sea wave" is also misleading. "Seismic" implies an earthquake-related generation mechanism, but a tsunami can also be caused by a non-seismic event, such as a landslide or meteorite impact. Tsunamis arise from the sudden displacement of gigantic water masses due to earthquakes on the sea bed, Volcanic eruption above and under water, landslides or meteorite impacts. About 86 % of all Tsunamis result from so-called seaquakes. The difference between tsunamis and normal waves or waves caused by strong wind is the large amount of distance there is between wavelengths. This is the distance from one wave crest to the next wave crest, which can be between 100 and 300 km. Even though they can travel up to 1 000 km/h, these waves are generally not noticeable in deep waters. The wave itself only becomes dangerous once it has arrived at land. In coastal areas where water levels slowly become shallower, the wave will slow down but rise into a wave wall as much as 30 meters high. The reason for this is the mass of water and energy held in the tsunami wave. Whereas only the upper water layers are being moved in wind created waves, with a Tsunami wave, an entire mass of water from the sea bed to the surface is in motion. If a trough tsunami wave reaches land first, the water will be pulled back into the sea by enormous currents. In this case, and if recognised, people on the beach and beachfronts have between a few minutes and half an hour to escape to higher ground. The time to escape depends on when the wave crest strikes the land. The first wave, that can grow to be up to 30 meters high at the beach, will usually be followed by more waves that are sometimes even more large and more dangerous. Not only the crests of waves are dangerous but also the troughs, since their currents are strong enough to pull people and whole houses many miles into the sea. The Tsunami Alarm warning time can be between a few minutes up to several hours, depending on distance from the earthquake's epicentre. The effects of a tsunami on a coastline can range from unnoticeable to devastating. The effects of a tsunami depend on the characteristics of the seismic event that generated the tsunami, the distance from its point of origin, its size (magnitude) and, at last, the configuration of the bathymetry (that is the depth of water in oceans) along the coast that the tsunami is approaching. Here's a video that shows the effects of earthquakes: https://www.youtube.com/watch?v=_Cq5Fqfo98k |