How do Earthquakes Happen

It's time to leaf through your Geography textbooks and learn the mechanism behind earthquakes. For kids keen to unfold the mystery, this lesson for the day goes as follows.
It's one of the most destructive forces of nature. It happens when two blocks of earth slip past one another, all of a sudden. This is what is defined as an earthquake. Many a time, earthquakes have foreshocks, which means that with a humongous earthquake, there are smaller earthquakes that occur in the same place. These small earthquakes are termed as foreshocks, which, sometimes, make it impossible for scientists to predict until the bigger earthquake occurs at a particular area. While foreshocks are small, mainshocks are the actual or main earthquake, which is followed by aftershocks. The effects of aftershocks entirely depend on how big the mainshock is, for aftershocks may continue for weeks, months, and even years post mainshock. That said, there is a bit of information on how exactly do earthquakes happen. To unleash the hidden facts, the following section makes up for a must-read.

The Science Behind Earthquakes

Unlike many mysteries that the world holds within, there are no ambiguities that brim exactly what causes earthquakes. The reason being a simple fact that as per what scientists have revealed, there are two understandings behind the occurrence of earthquakes - eruption of the volcanoes and disturbance in the tectonic plates of the earth. When the molten magma under the earth's crust releases its pressure, it searches for an opening, thereby, exerting enormous pressure on the crust, thus, erupting a volcano. This, in turn, exerts pressure on the tectonic plates too. As is universally known, there are four main layers of the earth that comprise the crust, the mantle, the outer core, and the inner core. The crust and the mantle form a strong layer of the earth called the lithosphere, which further breaks down into plates known as the tectonic plates. Just so you know, the plates which underline the oceans are called oceanic plates, while the ones that underline the continents are known as continental plates.

As a result of volcanic eruptions, the mantle within the earth's crust moves, thereby, moving the plates as well. Oftentimes, the plates start pulling away from each other, and bump into one another, creating either of the three types of movements - extensional, compressional, and transform. These three types of movements create three distinct kinds of earthquakes. Understanding a few simple facts on earthquakes could help you figure out as to exactly where do earthquakes happen. Well, it is the very area where a volcano erupts that is prone to earthquakes the most, and since, the pressure exerted by the magma exceeds the limit, it is these tectonic plates that get disturbed, thus, moving from their original places or resettle. Needless to say, this can result into severe tremors on the surface of the earth.

Not only are volcanoes the key reason behind exactly why do earthquakes happen, it is also the enormous exploitation of the resources of the earth by humans that causes earthquakes. Various earthquake facts let slip that building dams and storing heaps of water, bomb-blasting, creating bridges and roads anywhere and everywhere would definitely cause natural disruptions in the earth's atmosphere, and rapid developments and establishments by humans in order to improve the way of living clearly outline how and why earthquakes happen so frequently in the world.

The Great Chilean Earthquake was the biggest earthquake ever recorded in the history of humankind, with a magnitude of 9.5 on the Richter scale. Out of the various stakes that earthquakes involve, the increasing population of the world is exposed to maximum risk. It is dreadful to see how earthquakes happen to damage the world so brutally, and how we, as humans, can do nothing but prepare ourselves for yet another disaster.
By Veethi Telang
Last Updated: 9/26/2011
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