What is a earthquake?

An earthquake is a natural phenomenon that occurs as a violent shaking or vibration of the earth surface. This can be caused by a number of events. There are earthquakes that can be man-made. It can be as simple as a surface vibration caused by a passing truck or as serious as an human-induced explosion.

What causes  an earthquakes?

Natural earthquakes are usually more destructive and can be caused by the dislocations of the earth's crust. This happens when energy generated in the earth's interior transfers into the crust, causing friction between the plates. This goes on until the frictional strain becomes too much for the plates to absorb. This in turn causes a violent displacement of the crust that shakes the ground, causing an earthquake.

The surface layer of the earth's exterior is made up of many plates that continuously slides over the earth's hot liquid interior. The plates also grinds with each other. When the threshold of frictional strain between the plates is reached, the following may happen:

Plates slide against each other. In this case, one plate may move north while the other one slides south. As both plates slide, they can also be pushed tightly against each other that causes a great deal of tension in the area where the two plates meet.

Plates can move apart. The two plates separate from each other, creating a gap where hot, molten rock flows up from the layers of mantle below the earth's crust. This magma then oozes out to the surface and becomes lava. As the lava cools, it hardens to form new crust that begins to fill in the gap. This usually happens in many areas below the ocean.

Plates can push against each other. Two plates can move toward each other with one plate pushing under the other one. This action makes one of the plates to sink into the lower mantle layers, where it begins to melt. But there are some areas in the earth's crust where neither of the plates are positioned to sink from under the other. Instead, they both push against each other, causing the crust to be pushed upwards. This type of occurrence enabled the mountains to form.

Consequences of the earthquake

Such events can either cause destructive earthquakes or minimal rumbles of the earth small enough not to be felt. Earthquakes can also cause other things to happen. In some areas, severe earthquakes can cause the liquefaction of the soil. This happens when violent shaking of an earthquake causes loosely packed sediments and soil to behave like a liquid. When a building or house is built on loosely packed soil, liquefaction can cause the building structure to sink and eventually collapse.

Highly developed areas such as beach front properties that are built on loose ground can suffer severe damage from even a mild earthquake. Liquefaction can also cause severe mudslides if ever such earthquakes happen near elevated or depressed areas.

Severe earthquakes that happen somewhere on the ocean floor can cause destructive tsunamis or tidal waves to form. This happens when the seismic waves of an earthquake radiates or transfers into the surrounding body of water, causing waves to form. The waves may not look massive in deep ocean where the seismic energy is spread over a large area.

But when the wave approaches shallow water, the area of concentration decreases which forces the wave to increase in size and the speed of approach. When it gains landfall, it becomes a large wave with energy strong enough to cause destruction to of anything that it passes.

On land, severe earthquakes can cause considerable damage to both life and property. It has the power to decimate city blocks and cause buildings and houses to collapse. Many earthquakes that happened throughout history has caused untold damage to property and loss of millions of lives. The destruction caused by earthquakes can't be avoided. But the loss of lives of an impending can certainly be prevented by being well-prepared.

Detection and recording

Early detection of earthquakes is one of the best ways of trying to lessen the loss and destruction that it can cause. With early detection, warnings can be sent out to help prepare the people way before actual event. Rescue teams can be put on standby immediately and sent to the affected areas at the aftermath of an earthquake. Scientist today are studying ways of detecting an impending seismic event at the earliest time possible.