Earthquakes

All of us must have noticed that our house shakes, whenever a bus or heavy duty vehicle goes past it

This is because when a heavy duty vehicle moves, it cause vibrations in the ground

This vibration then gets transmitted over some distance through earth's surface into the structure of your house, finally causing it to vibrate

But this type of vibration is not of huge intensity, that is why does not cause any destruction

When the intensity of this vibration is large enough, it has the capability to destroy a whole region

High intensity vibration of earth's surface which can cause huge destruction is called as Earthquakes

Let us have one very common example to understand the cause of Earthquake

A pencil is brittle in nature but as we try to bend it a little, we can see its elastic nature also

Similarly, the rigid outer part of the Earth, called lithosphere, is also brittle with some extent of elastic nature

Both the pencil and lithosphere are capable of storing energy, but both are also capable of breaking and releasing the stored energy in the form of vibrations and sound

This release of stored energy in case of Earth as one rock surface moves against another is called Earthquake

Let us now see the cause of earthquake

The Earth’s crust consists of large lithospheric plates and numerous smaller plates

The continuous motion of these plates causes a rise in pressure in the rock until the stress is sufficiently great that it is released in a sudden, jerky movement

The resulting waves then propagate through the ground and over its surface, causing the shaking of earth's surface, which we called as Earthquakes

The image describes the formation of earthquake

Unlike cyclones and lightning which can be predicted, earthquakes cannot be predicted, accurately

The shock waves radiate out from the point where the rocks first begin to break(fault), this point is called the focus of the earthquake

Epicenter is the point on the Earth's surface directly above the focus, where an earthquake originates

The effects of an earthquake are terrible and devastating

So let us now see the effects of earthquake

Some of the common effects of earthquakes include structural damage to buildings, fires, damage to bridges and highways, initiation of slope failures and tsunami

The types of effects depend to a large degree on where the earthquake is located: whether it is predominantly urban or rural, densely or sparsely populated, etc

Ground shaking is the most familiar effect of earthquakes. It is a result of the movement of sudden high energy stored waves through the earth's surface

This includes building damage and multi-storey buildings tend to be more seriously damaged than smaller ones

Ground rupture is another dangerous effect of earthquakes which occurs when earthquake finally breaks the Earth's surface

Landslides are caused by earthquakes both by direct rupture and by shaking of unstable slopes. They can easily destroy buildings in their path, or block roads and railroad lines

Image shows landslides due to earthquake in hilly areas

Earthquake also causes a huge loss of life and property

Revision

An earthquake is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earth's lithosphere that creates seismic waves

The shock waves radiate out from the point where the rocks first begin to break, this point is called the focus of the earthquake

Unlike cyclones and lightning which can be predicted, earthquakes cannot be predicted, accurately

Some of the common effects of earthquakes include structural damage to buildings, fires, damage to bridges and highways, initiation of slope failures and tsunami

The types of effects depend to a large degree on where the earthquake is located: whether it is predominantly urban or rural, densely or sparsely populated, etc

The End