World Distribution of Earthquakes

To describe the distribution of earthquakes in the world, aspirants need to understand the science behind an earthquake. An earthquake is a sudden jolt or shaking of the earth’s surface, leading to mass destruction. Preparing for the IAS exam calls for in-depth knowledge about all the topics and earthquakes, and their frequency across the countries of the globe is one of them. Learning about the reasons and types of an earthquake is also essential.

For detailed information about the types, causes, effects and measurement of earthquakes, aspirants can download the NCERT notes of Earthquakes at the linked article.

Why do earthquakes occur?

One of the most recurrent topics of the UPSC syllabus is the theories related to an earthquake. An earthquake occurs when two blocks of the earth move past one another on a surface, popularly known as the fault plane or simply a fault. An earthquake occurs whenever these plates deviate from their paths and move away from the faults. The area where an earthquake begins below the earth’s surface is called a hypocentre and one above the earth’s surface, the epicentre.

A part of the UPSC prelims delves into the study of earthquakes. The earth’s surface is primarily divided into four layers, the outer and inner core, the mantle and the crust. The upper layer of the earth’s surface, the mantle and the crust are divided into tiny pieces known as tectonic plates. The boundaries of these tectonic plates made up of several faults are where most earthquakes occur.

Classification of Earthquakes

Earthquakes can be classified into the following types:

• Volcanic Eruptions

When a volcano erupts, the molten lava tries to escape the earth’s surface through the crevices present on the earth’s surface. The pressure these gases release sends shockwaves below the earth’s surface, resulting in earthquakes. However, these are mostly relatively mild in strength.

• Tectonic Movements

Constructive, destructive and conservative are the three kinds of tectonic plate movement. When two tectonic plates move away from each other, causing minor earthquakes, they are called Constructive earthquakes. When they move towards each other and collide, it creates destruction and powerful earthquakes. These are called destructive earthquakes. Finally, where the tectonic plates slide past each other, causing earthquakes of varying densities, it is referred to as conservative earthquakes.

• Man-Made Earthquakes

Human activities such as heavy mining, the creation of dams, and nuclear bombing are a few of the reasons that have led to earthquakes all over the earth.

These questions come quite frequently in Current Affairs Quizzes. So, include these earthquake types in your notes.

Candidates can get answers to questions based on earthquakes and tectonic movements by referring to the links given below:

Distribution of Earthquakes around the World

As you prepare for the UPSC 2023, it is essential to know that most earthquakes occur along the boundaries of the tectonic plates. The distribution of earthquakes in world is as follows:

• The Circum-Pacific Belt or the coasts around the Pacific Ocean are affected by earthquakes comprising the populated regions around the Pacific Ocean such as New Zealand, New Guinea, Japan, Alaska and the western coasts of North and South America. The volcanic activity around this belt is distributed throughout at varying intensities naming this belt the ‘Pacific Ring of Fire’. Approximately 68% of the earthquakes around the world occur in this belt.
• The Alpine Belt comprises 15% of the world’s earthquakes. Extending parallel to the equator from Mexico across the Atlantic Ocean, this belt ranges from the Mediterranean sea to the Alpine-Caucasus range to the Caspian Sea, across the Himalayan ranges and its adjoining areas.
• The Rift Valleys of East Africa is another such region along with the oceanic ranges of the Arctic, Atlantic and Western Indian Ocean, where one can witness a widely connected zone of seismic activities.

An aspirant’s preparation for the UPSC cannot be complete without incorporating the distribution of earthquakes in the world. Therefore, the descriptions as mentioned above should be learnt by heart.

Aspirants can visit the linked article and get details about the upcoming government exams that comprise current affairs and general awareness as an important topic in the syllabus.

For the best preparation strategy for competitive exams candidates can visit the linked article and get detailed study material and preparation tips to excel in the examination.