Earthquakes are nothing but the tremors arising from seismic waves.

What are these seismic waves, you ask?

Well, the earth’s crust is made up of 7 large and several smaller tectonic plates. When two such plates suddenly slip past each other, the friction between them disperses waves of seismic energy to the adjoining areas.

There are several other causes of earthquakes. However, before delving into those, you first need to understand the types of earthquakes.

Earthquakes all over the world originate along the fault lines between two tectonic plates. You can refer to this image below for understanding worldwide plate tectonics better.

Based on the origin, earthquakes all over the world can be classified into four categories.

Tectonic Earthquakes

These are earthquakes caused by natural tectonic plate movements. These quakes are the most common ones worldwide, usually occurring at the boundaries of the tectonic plates.

Tectonic quakes are the most devastating ones all over the world and usually originate from deep underground.

Volcanic Earthquakes

Volcanic earthquakes are associated with active volcanoes and occur when the volcano erupts. When a volcano erupts, it releases an enormous amount of embedded pressure. This pressure generates seismic waves and causes the earth to shake.

Volcanic earthquakes are usually not as strong as tectonic ones and occur near the surface. Hence, they are usually felt close to the hypocentre.

Induced Earthquakes

Human activities usually cause induced earthquakes. Man-made causes of earthquakes include tunnel construction, implementing geothermal or fracking projects, nuclear bombings and filling reservoirs.

Collapse Earthquakes

Collapse earthquakes occur due to extensive cave-ins. These quakes usually occur in karst areas or in the vicinity of mining facilities due to subsidence.

Now that you have understood the different types of earthquakes, let’s take a look at the detailed causes of this natural disaster.

The main cause of earthquakes here is the Indian plate’s gradual shift towards the Eurasian plate at an annual rate of about 50 mm. This gives rise to the most common tectonic earthquakes.

Other causes of earthquakes in India include human activities and cave-ins, as already discussed in detail under induced earthquake types.

Earthquakes always leave devastating effects in their wake. There are two types of effects in the event of an earthquake - primary and secondary.

• Primary Effects: Several structures collapse, including educational institutions, medical establishments, historical statues and monuments. An entire village, town or city can get demolished in the event of an earthquake.

Besides facing death and injuries, people also lose their money and property. As a result, earthquakes also leave the victims emotionally weak.

• Secondary Effects: Secondary effects mainly include the environmental ones. Earthquakes often cause tectonic uplift and subsidence, surface faulting, soil liquefaction, tsunamis, landslides, ground resonance, etc.

Some constructive effects of earthquakes include changes in coastlines, formation of waterfalls, lakes, landforms, estuaries, gulfs, etc.

Besides the causes of earthquakes, you should also know the safety measures to be followed during an earthquake. 

Here are some of them -

• Keeping calm and reassuring others.
• Moving away from buildings and electrical wires to open spaces.
• Taking cover under a desk or table if you are indoors.
• Staying away from glass doors and windows if you are indoors.
• Stop and stay inside your vehicle if you are driving.
• Set your pets free to let them run outside.
• Put out all kinds of open flames.

Earthquakes cannot be predicted or prevented. However, you can opt for a home insurance policy to get covered against property damages arising from earthquakes. A valid home insurance policy can provide you with financial support to deal with the damage repair, renovation and rebuilding expenses.

India has experienced a number of earthquakes over the last century. Studies show that over 59% of India’s land mass is prone to earthquakes. In fact, the entire north-eastern region, including the Himalayan belt, is at risk of experiencing earthquakes with a magnitude above 8.0.

With a clear understanding of the effects and causes of earthquakes, along with the safety measures and insurance options, we hope you will be able to deal with earthquakes in a better manner.