Earthquakes are defined as a sudden and violent shaking of the ground. They are caused by the shifting of tectonic plates, which are pieces of the earth’s crust. When these plates crash into each other they “remain locked until enough pressure builds that one of them is forced under the other.” (univertoday.com) This process is called ‘subduction,’ and is responsible for the shock that travels up to the earth surface causing an earthquake. The shock waves that travel to the surface are known as ‘surface waves’, while the ones that stay in the planet are known as ‘body waves.’ The area in which these plates come together is known as faults, and most earthquakes happens around these fault lines.
Earthquakes are measured on a Richter scale, developed in 1935 by Charles Richter, which measures and show the amount of energy release by a quake. The scale measures magnitudes from 0-10 usually, but actually has no limits either way.
- Earthquakes measuring less than 4.0 magnitude occur in small areas and might not even be noticed, much less cause any serious damage.
- Earthquakes measuring 4.0–4.9 magnitude cover a larger area. They are felt, but damage is light.
- You start to see some damage with a 5.0-magnitude earthquake, starting with poorly constructed buildings.
- Higher up on the Richter scale, you see greater damage over a greater area.(dummies.com)
Earthquakes have different kinds of shocks as well. Before the major shock of an earthquake, foreshocks take place. No one can tell if an earthquake is a foreshock, until the major shock happens. The major shock is also known as the main shock, and is followed by aftershocks which can continue for weeks or even months after.
Earthquakes, on top of the damage they already cause, can cause a host of other things than can lead to more death and destruction. This includes:
Earthquakes, on top of the damage they already cause, can cause a host of other things than can lead to more death and destruction. This includes:
- Avalanches and landslides
- Tsunamis