An earthquake occurs when the Earth's crust shifts and releases energy in the form of seismic waves from within the planet. The two main parts of an earthquake are the hypocenter and the epicenter. Earthquakes can be classified into several types depending on their origin, whether natural or caused by human activity.
In this article we are going to tell you what they are the parts of an earthquake, how it originates and some types of earthquakes that exist.
Characteristics of an earthquake
Earthquakes can be classified based on their classification, which takes several factors into account.
- Origen
- Magnitude
- Forms
However, each of these phenomena is characterized by its fleeting nature, that is, it They only last a short period of time, ranging from a few seconds to, sometimes, a couple of minutes. To understand the entirety of this event, it is necessary to understand certain fundamental concepts.
Among the parts of an earthquake we have the hypocenter and the epicenter.. The hypocenter of an earthquake, also known as its point of origin, is distinguished from the epicenter, which simply refers to the location on the Earth's surface directly above the hypocenter.
Once we have established our understanding of what constitutes an earthquake, let's delve into the mechanics of how these seismic events occur and uncover their underlying origins.
It is a fact that tectonic activity is mainly responsible for the occurrence of earthquakes. This phenomenon is based on the knowledge that the Earth's lithosphere is formed by tectonic plates that have the ability to slide and potentially collide with each other, giving rise to tectonic activity. It is precisely this movement and collision of plates that explains most earthquakes.
Parts of an earthquake
As we have mentioned before, the main parts of a whole terrain are the following: hypocenter and epicenter.
The hypocenter, also known as the seismic focus, It is the point within the Earth where the rupture that causes the earthquake begins. This point is generally located several kilometers deep in the Earth's crust. It is here where the accumulated stresses exceed the resistance of the rocks and energy is released in the form of seismic waves. The depth of the hypocenter can vary widely, from a few kilometers to hundreds of kilometers in some cases of deeper earthquakes.
On the other hand, the epicenter is the point on the Earth's surface that is directly above the hypocenter. Although the hypocenter is the place where the earthquake originates, The epicenter is the place where the most intense effects are normally felt and where the greatest material damage is usually concentrated. This is because seismic waves propagate outward from the hypocenter and reach the surface, causing ground movement.
Types of earthquakes
There are different types of earthquakes depending on their origin. There are earthquakes considered natural and others with artificial causes. Let's see what the different types are:
Natural causes
- Tectonic earthquakes: They are the most common and occur when tectonic plates come into contact with each other or, in rare cases, when there are weak points within the plates.
- Volcanic earthquakes: are a specific type of seismic activity caused by the fragmentation of rock due to volcanic activity in a given region.
- Collapse earthquakes: They are characterized by abrupt displacements of rock or soil masses, such as when a slope experiences a rapid descent followed by seismic activity.
Throughout history, the occurrence of earthquakes caused by meteorite impacts on planet Earth has been rare; however, There have been cases of seismic activity resulting from the intense vibrations produced after the impact.
Earthquakes caused by human activities
When it comes to earthquakes caused by human activities, known as anthropogenic earthquakes, we can identify several types that are worth mentioning:
- Earthquakes induced by reservoirs They are the result of the excessive weight of water in reservoirs and the abrupt changes that occur during its release. On the other hand, seismic activity caused by nuclear explosions tends to be moderate in magnitude, while earthquakes caused by mine and quarry explosions are usually smaller in scale.
- The hydraulic fracturing process, commonly known as fracking, is used to extract natural gas and oil. This method often causes microearthquakes and sometimes larger seismic events as a result of ground fractures.
How earthquakes are measured
Earthquakes can be measured in several ways, with different scales assessing the magnitude or intensity of the event. However, The most used scale is the Richter scale, also known as the local magnitude scale (M). This logarithmic scale quantifies the magnitudes of earthquakes based on the force and energy released during the event. Specifically, the Richter scale allows measuring earthquakes of magnitude 2 to 6,9 and that occur at depths of 0 to 400 kilometers.
Additionally, the seismological moment magnitude scale is commonly employed due to its ability to evaluate earthquakes of magnitudes greater than 6,9, providing a more precise determination of extreme values. This scale also evaluates rock stiffness and average displacement distance.
Consequences of an earthquake
Although there is usually some knowledge about the formation and measurement of earthquakes, it remains undeniable that the magnitude and intensity of these seismic events can have a multitude of consequences.
- One of the frequently observed consequences of an earthquake is the breaking up of the terrain, leading to extensive destruction of buildings, infrastructure such as roads and highways, and various other structures. Additionally, flooding can occur after an earthquake due to dam failure or shifting river beds, causing catastrophic flooding.
- Landslides They are caused by the abrupt displacement of tectonic plates, which causes instability in both valleys and mountains and leads to the appearance of landslides.
- The tsunamis, also known as tidal waves, are the result of the vertical movement of massive masses of water, which manifest as a series of powerful waves of different sizes. These tsunamis can be caused by different factors, such as earthquakes that originate in the middle of the ocean or earthquakes that have their epicenter near coastal areas.
I hope that with this information you can learn more about the parts of an earthquake and what its consequences are.