An earthquake is a violent, rapid, and vibrating movement of the Earth’s surface that is caused by disturbances that affect the interior of our planet. An earthquake can be a tremor, a movement of low intensity, or an earthquake, a movement of greater intensity with almost destructive power.
What is an Earthquake?
It is the tremor or shaking of the earth due to internal movements. In some countries, the term earthquake is used to refer to tremors that have a low intensity and are not considered earthquakes.
They are usually produced by the collision of tectonic plates, this causes a release of energy and the reorganization of the Earth’s crust. The movements continue until the cortex returns to equilibrium.
Other processes that cause earthquakes are the movements of the slopes, the collapse of karst cavities, volcanic processes, and the deformation of the rocks present in a fault. They can also be produced by changes in atmospheric pressure, alterations in the river regime, and human intervention.
The place where the earthquake originates is known as the seismic focus or hypocenter, from there and in a vertical direction to the surface, we will find the epicenter. In this place, the seismic waves have their greatest power.
Types of earthquakes:
There are different earthquakes and they can be classified according to their origin, magnitude and movement:
Types of earthquakes according to their source
Natural earthquakes: are those that occur due to completely natural causes and release large amounts of energy.
Artificial earthquakes: they are caused by humans due to explosions, especially from weapons for war.
Types of earthquakes according to their magnitude
Microseisms: they do not cause damage to the earth’s surface. They do not exceed a magnitude of 3 on the Richter scale.
Minor earthquakes: are those that cause minor damage and have a magnitude ranging from 3 to 3.9 on the Richter scale.
Light earthquake: damage is reported, but of little importance. Its value ranges from 4 to 4.9 on the Richter scale.
Moderate earthquake: it has a magnitude of between 5 and 5.9 on the Richter scale and can cause damage to precarious buildings.
Strong earthquake: it is considered an earthquake, its magnitude ranges from 6 to 6.9 on the Richter scale and causes serious damage.
Major earthquake: its magnitude ranges from 7 to 7.9, it can cause irreparable damage to buildings and infrastructure.
Great earthquake: it is the most powerful, it produces serious damage to buildings and the earth’s crust, it can cause tidal waves and strong aftershocks. Its magnitude is greater than 8 on the Richter scale.
Epic magnitude: it is considered by scientists as an earthquake that can destroy 80% of the planet by overflowing the seas, altering the course of rivers and modifying the geography of the planet. It is a theory that severely worries seismologists.
Types of earthquakes according to their origin
Preliminary earthquake: these are the earthquakes that precede an earthquake, they initiate the release of energy.
Perimetric earthquake: it is the earthquake caused in the tectonic plates.
Tectonic earthquakes: they are caused by the collision of tectonic plates.
Volcanic earthquakes: they are produced by the release of magma, which fractures the rocks. It is not very powerful, but it can cause severe damage.
Tsunamis: These are seismic movements that occur deep in the ocean. If they release a lot of energy, they can displace large amounts of water, causing flooding and damage to the coasts.
Types of earthquakes according to the movement of the earth
Oscillatory earthquake: it is caused by waves that propagate in different directions. It produces a feeling of dizziness similar to being in the sea.
Trepidatory earthquakes: they occur in areas close to the tectonic plates and the epicenter, the movement is vertical and objects and buildings give the impression of jumping.
Earthquakes contain two types of motion, trepidation and wave motion.
What can we do to reduce the effects of earthquakes?
The work of seismologists has allowed the development of systems that warn of the arrival of an earthquake a few seconds before it occurs, offering the population enough time to seek shelter. However, it is impossible to predict the occurrence of an earthquake well in advance.
Animals can perceive small earthquakes and a change in their behavior can be a warning of an earthquake about to occur.
The construction of earthquake-resistant homes in earthquake-prone areas is necessary. You must also have a prevention and protection plan in the event of an earthquake.
Before an earthquake you should know the exits from your home or building. If the family is separated, everyone should know a meeting point and keep it memorized. It is also necessary to have a backpack or earthquake kit that contains water, a first aid kit, a copy and original of important documents, non-perishable food, a tent and clothing.
You must know where the main gas, water and main electricity switch is, as you must cut off all services after an earthquake to avoid accidents. Heavy objects should be securely secured to the walls so that they do not fall during a strong earthquake.
