An earthquake is a natural disaster that occurs when the surface of the Earth shakes and trembles. Numerous earthquakes happen every day but they are not strong enough for people to sense them. However, once in a while, a major earthquake with bigger consequences occurs.
But let’s see what an earthquake is. The crust of the Earth is its outer layer and it consists of pieces called tectonic plates. Those plates are constantly moving very slowly and sometimes they collide together. Pressure begins building up under them and if it escapes, it sends shock waves to the surface of the Earth. We call those waves seismic waves.
Through the seismic waves we can also tell how strong an earthquake was. They are measured with a seismograph by the seismologists – the scientists who study earthquakes. Then they use the Richter scale to define the intensity of the earthquake. If it measures 3 on the scale, most people can not even sense it; on the other hand, an earthquake that scores 8 or more can cause houses to fall, cracks to appear on the surface of the Earth, and people to get seriously injured.
Usually a major earthquake is followed by some smaller ones, called aftershocks. In most cases pressure trying to escape causes a series of smaller shocks as well – we call them foreshocks.
There is a difference between epicenter and hypocenter. Hypocenter is where the earthquake starts, beneath the surface, whereas the epicenter is located directly above it on the surface itself.
We all agree that earthquakes are scary. Seismologists have not found a way to predict them yet. But there are a coupe of things we can do to stay as safe as possible during an earthquake. The most important one is to remain calm!! Then, if you are inside, find something sturdy to go under – a heavy table, a desk or even the frame of a door. This will protect you in case objects start falling down. Once the shaking has stopped, go outside in the open and try to avoid the proximity of tall buildings and trees.