Hello student,

Hope you are doing well

Coming to your question any sudden shaking of ground is called Earthquake . This is caused when some form of energy get released in the form of seismic wave through earth's rocks.

Earthquakes often occur at geographical region where rocks move with respect to another. About 50000 earthquakes occur annually every year all over the world .

Most important earthquake belt is Circum- Pacific belt which includes many populated regions like japan , new zealand, new guinea , alaska etc. This belt is popularly called as " Pacific ring of fire " as these earthquakes are often associated with volcanic activity.

Earthquakes are generally natural but sometimes it is caused by some man made activities like underground neclear explosion, excavation of mines and filling of large reservoirs. Earthquakes can sometimes cause tsunami.

Hope this helps!!

Good luck!!!

Hello,

Earthquakes can be human-made or natural, although the latter is more abundant. These earthquakes are not random; rather, they are the effect of different changes occurring in the earth’s crust for a long time.

The main causes of earthquakes fall into five categories:

1.  Volcanic Eruptions

The main cause of the earthquake is volcanic eruptions. Such type of earthquakes occurs in areas, with frequent volcanic activities. When boiling lava tries to break through the surface of the earth, with the increased pressure of gases, certain movements caused in the earth’s crust. Movement of lava beneath the surface of the earth can also cause certain disruptions. This sends shockwaves through the earth, causing damage. These earthquakes are mild. Their range is also limited. However, there have been certain exceptions, with volcanic earthquakes bring havoc and death to thousands of peoples.

2. Tectonic Movements

The surface of the earth consists of some plates, comprising of the upper mantle. These plates are always moving, thus affecting the earth’s crust. These movements categorized into three types: constructive, destructive, and conservative. Constructive is when two plates move away from each other, they correspond to mild earthquakes (https://www.infocuriosity.com/tag/earthquakes) . When two plates move towards each other and collide, this is known as destructive plate boundaries. This is very destructive. Conservative corresponds to passing by of plates of crust. Earthquakes of this type have varying intensities.

3. Geological Faults

A geological fault is known as the displacement of plates of their original plane. The plane can be horizontal or vertical. These planes are not formed suddenly but slowly develop over a long period. The movement of rocks along these planes brings about tectonic earthquakes. These faults occur due to the impact of geological forces. The displacement of plates creates the fracturing of rocks, which releases a lot of energy. This type of earthquake can be disastrous.

4. Man-Made

The interference of man with nature can also become a cause of the earthquake. The disturbance of crustal balance due to heavy clubbing of water in dams can cause earthquakes. Nuclear bombing can send specific types of shockwaves throughout the surface of the earth, which can disturb the natural alignment of tectonic plates. Mining can also cause disturbance due to the extensive removal of rocks from different areas.

5. Minor Causes

Some minor causes such as landslides, avalanches, the collapse of heavy rocks, etc. can also cause minor shockwaves. The gases beneath the surface of earth contract and expand, giving rise to movements in plates beneath the crust. The plutonic earthquake occurs because of adjustments in rock beds in the interior of the earth’s crust. All these factors correspond to minor earthquakes, but sometimes these can also vary to moderate earthquakes.

I hope this information help you.