I was sad last weekend when Arsenal lost to Brighton and Hove Albion. Although my profile states that I'm a former arsenal fan, truth is I console myself with that. While I was wallowing in my self induced despair, I thought about those that are really sad, the millions who have been displaced from their homes due to earthquakes. Those who have lost friends and family to this natural disaster.

This made me wonder why earthquakes occur, how it occurs and how deadly it can be. I read about it and now I want to share my newly acquired knowledge with you. Stay with me.

_{Wikimedia Commons: Road in Nepal after Earthquake}

What is an Earthquake

Earthquake is the impromptu frantic trembling of the earth surface, which happens as a result of underground motion along a fault plane or volcanic activity. The area below where earthquakes originate is known as the hypocenter while the area above is called the epicenter. It is unpredictable and happens with sufficient amount of force to bring down buildings.

According to National Geographic, 80% of earthquakes take place along the Pacific Rim called " The Ring of Fire " which is due to the massive volcanic activity there.

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Random fact about Earthquake

An Earthquake is capable of producing up hundreds times more energy than the nuclear bomb that was dropped on Hiroshima in Japan in 1945.

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What brings about Earthquakes

Earthquakes causes damages to structures , loss of property, also death to human. Mainly, earthquakes results from tectonic plates movement , volcanic activity and underground explosions

• Tectonic plates movement

Most earthquakes occur as a result of tectonic plates movement. Tectonic plates are large rock particles within the earth crust. The plates are characterized by fault line formed when they slip past each other, they induce shock waves. These shock waves are due to energy stored within the earth crust as a result of underground pressure of the earth's inner core.

The huge pressure from the shock waves make the fault lines to fall over and the plates to move up, against and over each other. Earthquakes occurs when the pressure stored along the fault lines becomes greater than the force holding the tectonic plates together. Which usually occurs when the plates unexpectedly split up at ultrasonic speed giving off the stored up pressure.

When this pressure reaches the earth surface, an earthquake occurs in the form of rippling bolt energy (seismic waves). This rippling effect is what is responsible for the swift and strong vibration of the earth surface, quavering and ripping apart everything on it including buildings and the earth itself.

• Volcanic activity

Aside tectonic plates movement, volcanic activity can also cause enormous earthquake. As molten magma rises to the crust during a volcano eruption it is usually followed by earthquake.This is due to the unexpected rearrangement of underground rocks.

Fault lines and underground rumbles which incite the unexpected slipping of tectonic plates can be created by volcanic activity. Which in turn frees up the stored pressure in all directions.

• Underground explosions

Underground explosions which maybe as a result of underground construction of railways, subways and also underground mining creates seismic waves that can invoke earthquake. Some Seismic waves produced by these explosions are not significant enough to cause an earthquake.

However, seismic waves as strong as those that causes natural earthquake can be produced by underground nuclear testing. Little wonder it is banned worldwide.

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Fun fact about earthquake

An earthquake on the moon is called a moonquake. Moonquakes are usually weaker than earthquakes.

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How to record the impact of an earthquake

The size of an earthquake is referred to as magnitude. Which is recorded by an instrument known as seismograph. The seismograph is rooted to the ground and has a free weight. When earthquakes happen, it shakes the ground. The base of the seismograph shakes too, but the free weight doesn't. The spring by which it's hanging stores all of the movement.

The variance in position between the moving part to the stationary part of the seismograph is what is recorded as the magnitude of the earthquake. Quakes measuring 3 -5 are referred to as minor or light, 5 - 7 are considered moderate or strong, while those between 7 and 8 are called major. Anything more than 8 is said to be great.

What to do in an event of an earthquake

In an event of earthquakes strong enough to cause the earth to shake, here are some of the things to do when the ground starts shaking.

• Stay low and take cover under a desk or table.
• Stay indoor until you are sure it's safe to exit.
• Move away from bookshelf and stuffs that can fall over.
• When driving, slow down and find a safe spot to park. And stay in the car.
• When outside, find a spot away from trees, buildings and power lines. Stay on the floor.
• In tall buildings, stay away from the windows and expect fail safe devices like fire alarm, sprinklers to go off.

Earthquakes prediction

Unfortunately, even with the wide range technological advancements, when and where an earthquake will occur can not be determined yet by scientific method. Many scientists have attempted and failed.

Conclusion

Although, little can be done to stop this natural disaster from ripping apart our dear beloved earth more can be done to prevent loss of lives during this incident. By building buildings that sway instead of those that buckle under the stress of an earthquake and also having proper emergency plan and education about earthquake will go a long way in reducing the number of casualties.

References

• National Geographic

• Earth Eclipse

• Wikipedia

• The science of earthquakes

• Earthquake safety tips

• Facts retrieval

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