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Seismic Zones of India
Seismic zones in India are regions that are classified based on the likelihood of earthquakes occurring in the area. The classification of Seismic zones in India is done by the Bureau of Indian Standards (BIS), and other agencies are the European Mediterranean Seismological Centre (EMSC), and the United States Geological Survey (USGS) which help in determining the design and construction standards for buildings and structures in different parts of the country.
For example, in high-risk seismic zones, building codes may require the use of stronger and more flexible materials, such as steel and concrete, and the structures may need to be designed to better withstand the forces of earthquakes. It’s important to note that the seismic zones are not static and can change over time as new data is gathered and analysed. Therefore, it’s crucial for building design and construction to take into account the latest seismic zone information and follow the appropriate standards for the area.
Seismic zones are determined based on several factors, including the historical record of earthquakes in the region, the type of geology and tectonic activity, and the level of seismic risk. The seismic zones are typically classified into several categories, with the most seismically active zones being designated as high-risk areas, and the least active zones being designated as low-risk areas.
Read about: Earthquakes in India
Seismic Zones of India Origin
Seismic zones form due to the movement of tectonic plates that make up the Earth’s crust. The Earth’s crust is broken into several large plates that move and interact with each other along plate boundaries. When two tectonic plates move away from each other, this is called a divergent boundary, and when two plates move towards each other, this is called a convergent boundary.
At a convergent boundary, one plate is forced beneath the other and is forced down into the Earth’s mantle. This process is called subduction, and it is at these subduction zones where most of the world’s largest and most destructive earthquakes occur.
Read More: Plate Tectonics Theory
The locations where earthquakes are most likely to occur are known as seismic zones, and these areas are typically associated with plate boundaries and areas where the Earth’s crust is undergoing significant deformation. Seismic zones can also form near active faults, where two blocks of the Earth’s crust have moved past each other along a fault plane.
The origin of seismic zones in India is primarily due to the tectonic activity associated with the collision of the Indian Plate with the Eurasian Plate. The Indian Plate, which began moving northward from the Southern Hemisphere about 50 million years ago, collided with the Eurasian Plate about 40 million years ago and continues to do so today. This collision has resulted in the uplift of the Himalayan Mountain range and the formation of the world’s highest peaks, including Mount Everest.
The collision of the Indian and Eurasian plates has also resulted in the formation of several active faults and fault zones that run through the Himalayas, the Indo-Gangetic plain, and other parts of the country. These faults are capable of producing large earthquakes, and the surrounding areas are considered to be seismically active.
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Seismic Zones in India Map
India is divided into four seismic zones based on the level of seismic hazard, with Zone 5 being the most seismically active and Zone 2 being the least.
Earthquake Zones of India
The following is a summary of the four Seismic Zones of India:
|Zone 5||This zone includes areas that are highly susceptible to earthquakes and includes parts of the northwest, northeast, and the Andaman and Nicobar Islands. Buildings in this zone are required to be designed and constructed to withstand the highest level of seismic activity.|
|Zone 4||This zone includes areas that are moderately susceptible to earthquakes and includes parts of the Himalayan region, the western and eastern coasts, and parts of the central and southern regions of the country.|
|Zone 3||This zone includes areas that have a low to moderate level of seismic hazard and includes parts of the central and southern regions of the country.|
|Zone 2||This zone includes areas that have a very low level of seismic hazard and includes parts of the northeastern region of the country.|
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Seismic Zones of India UPSC
The seismic zones of India are an important topic in the Union Public Service Commission (UPSC) exams, particularly in the context of disaster management and environmental geography. The UPSC exams often test the candidates’ knowledge of the geography, geology, and seismology of India and other parts of the world, and the seismic zones of India form a crucial part of the syllabus. The seismic zone map of India is regularly updated and revised to take into account new information and data on seismic activity. It is important for UPSC candidates to understand the seismic zones of India and the factors that influence the level of seismic hazard in different parts of the country.
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