Any sudden shaking of surface of earth which is caused by the passing of seismic waves through the Earth’s core is called an earthquake. When some form of energy is stored in the earth’s crust and then it is suddenly released, it causes the formation of seismic waves. Usually this happens when two huge rock masses holding up one another slip and suddenly fracture.
Earthquakes happen more often in some areas of the world. These regions are known as the fault lines of the world. In the regions, huge rock masses move opposite to each other and cause earthquakes. The major fault lines of the world are present at the edges of the tectonic plates which make the earth’s crust.
Seismology was introduced in the beginning of 20th century. Researchers and geologists knew very less about the earthquakes before it. Seismology is the scientific study of all the aspects and the causes of why do earthquakes occur. This study has answered so many unanswered questions.
Over the entire earth, about 50,000 of the big earthquakes are recorded annually. Big earthquakes are the earthquakes which are visible to a naked eye and can be observed without a measuring instrument. Amongst these 50,000 earthquakes, 100 are the ones which produce a substantial amount of damage in its surroundings.
It has been centuries since these deadly catastrophes have been wreaking havoc on the face of the earth. The biggest loss that humans face during these natural occurrences is the loss of other human lives. However, loss of wealth and damage of property are also an incalculable amount of loss.
Epicenters of Earthquakes;
According to the seismology, earthquakes are more likely to occur in the regions which lie above the tectonic plates. These areas are usually the epicenters of bigger earthquakes. The region which receives the most amount of these natural incidents is the Circum-Pacific Belt.
This belt touches a lot of coastal regions around the Pacific Ocean. Some of these highly populated and inhabited areas include the New Zealand, New Guinea, Alaska, Japan, Aleutian Islands and the western coast of the North and South of America.
This entire region is known as “the Pacific ring of fire”. It has so many volcanoes because of the seismic activities happening in the region. The intensity of this activity around the belt is not the same. Some countries receive more shocks than the other because there are different branches at various points.
There is another belt known as the Alpide Belt. This belt passes through the Mediterranean region and Asia to meet the Circum-Pacific Belt. This region includes most of the ocean ridges like the Indian Ocean, Atlantic Ocean and Arctic Ocean.
Causes of Earthquakes:
Earthquakes are caused by the gravity, elastic strain and chemical reactions between huge rocky masses. They can also be caused by the motion of huge bodies in the earth’s crust. Amongst all of these causes the release of elastic strain is the most common cause of this seismic activity.
Elastic strain is the only energy in the earth’s crust to create such disturbances on the surface of the earth. This type of earthquake is known as a tectonic earthquake.
A tectonic earthquake happens when two huge masses have opposed each other’s strength to a point where the tension between them becomes bigger than their own capacity of holding each other. This is when they fracture and a tectonic earthquake is recorded.
There is another type of earthquakes caused by the volcanic activities. These types of earthquakes are known as volcanic earthquakes. These volcanoes have trapped gas clouds inside them and when that gas is suddenly released it causes a disturbance on the surface of the earth.
Earthquakes are sometimes caused by human activities. A seismic activity can be observed as a result of an underground atomic explosion. Excavations of mines, injection of huge amount of fluids in deep wells or filling any sort of large reservoirs can also be the reason. All of these activities can cause an elastic strain to be released.
There are a number of countries which are continuously affected by these activities throughout the year. These nations have developed such lifestyles which can limit the loss of human lives or their economy due to these natural activities. If you are also an inhabitant of a region where you frequently face these activities, take care of yourself and your loved ones. Stay safe!