The Indian subcontinent has a history of devastating

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

s. The major reason for the high frequency and intensity of the earthquakes is that the

Indian plate The Indian Plate (or India Plate) is a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian Plate broke away from the other fragments of Gondwana , began ...

is driving into

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

at a rate of approximately 47 mm/year. Geographical statistics of India show that almost 58% of the land is vulnerable to earthquakes. A

World Bank The World Bank is an international financial institution that provides loans and grants to the governments of low- and middle-income countries for the purpose of pursuing capital projects. The World Bank is the collective name for the Inte ...

and

United Nations The United Nations (UN) is an intergovernmental organization whose stated purposes are to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmoniz ...

report shows estimates that around 200 million city dwellers in India will be exposed to storms and earthquakes by 2050. The latest version of seismic zoning map of India given in the earthquake resistant design code of India S 1893 (Part 1) 2002assigns four levels of seismicity for India in terms of zone factors. In other words, the earthquake zoning map of India divides India into 4 seismic zones (Zone 2, 3, 4 and 5) unlike its previous version, which consisted of five or six zones for the country. According to the present zoning map, Zone 5 expects the highest level of seismicity whereas Zone 2 is associated with the lowest level of seismicity. File:Earthquake hazard zoning map of India.gif, Revised earthquake hazard zone map of India

National Center for Seismology

The National Center for Seismology

Ministry of Earth Sciences The Ministry of Earth Sciences was formed on 29 January 2006 from a merger of the India Meteorological Department (IMD), the National Centre for Medium Range Weather Forecasting (NCMRWF), the Indian Institute of Tropical Meteorology (IITM), Pune ...

is a nodal agency of the

Government of India The Government of India (ISO: ; often abbreviated as GoI), known as the Union Government or Central Government but often simply as the Centre, is the national government of the Republic of India, a federal democracy located in South Asia, ...

dealing with various activities in the fields of

seismology Seismology (; from Ancient Greek σεισμός (''seismós'') meaning "earthquake" and -λογία (''-logía'') meaning "study of") is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other ...

and allied disciplines. The major activities currently being pursued by the National Center for Seismology include a) earthquake monitoring on a 24/7 basis, including real time seismic monitoring for early warning of tsunamis, b) operation and maintenance of national seismological network and local networks, c) seismological data centre and information services, d) seismic hazard and risk related studies, e) field studies for aftershock/swarm monitoring snf site response studies and f) earthquake processes and modelling. The MSK (Medvedev-Sponheuer-Karnik) intensity broadly associated with the various seismic zones is VI (or less), VII, VIII and IX (and above) for Zones 2, 3, 4 and 5, respectively, corresponding to Maximum Considered Earthquake (MCE). The IS code follows a dual design philosophy: (a) under low probability or extreme earthquake events (MCE) the structure damage should not result in total collapse, and (b) under more frequently occurring earthquake events, the structure should suffer only minor or moderate structural damage. The specifications given in the design code (IS 1893: 2002) are not based on detailed assessment of maximum ground acceleration in each zone using a deterministic or probabilistic approach. Instead, each zone factor represents the effective period

peak ground acceleration Peak ground acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a par ...

s that may be generated during the maximum considered earthquake

ground motion Ground motion is the movement of the earth's surface from earthquakes or explosions. Ground motion is produced by seismic waves that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the earth a ...

in that zone. Each zone indicates the effects of an earthquake at a particular place based on the observations of the affected areas and can also be described using a descriptive scale like the

Modified Mercalli intensity scale The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. It measures the eff ...

or the

Medvedev–Sponheuer–Karnik scale The Medvedev–Sponheuer–Karnik scale, also known as the MSK or MSK-64, is a macroseismic intensity scale used to evaluate the severity of ground shaking on the basis of observed effects in an area where an earthquake transpires. The scale was f ...

Zone 5

Zone 5 covers the areas with the highest risk of suffering earthquakes of intensity MSK IX or greater. The IS code assigns a zone factor of 0.36 for Zone 5. Structural designers use this factor for earthquake resistant design of structures in Zone 5. The zone factor of 0.36 (the maximum horizontal acceleration that can be experienced by a structure) is indicative of effective (zero period) level earthquakes in this zone. It is referred to as the Very High Damage Risk Zone. The regions of Kashmir, the

Western Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US *Western Creek, Tasmania, a locality in Australia *Western Junction, Tasmania, a locality in Australia *Western world, countries that id ...

and Central Himalayas, North and Middle Bihar, the North-East Indian region, the

Rann of Kutch The Rann of Kutch (alternately spelled as Kuchchh) is a large area of salt marshes that span the border between India and Pakistan. It is located in Gujarat (primarily the Kutch district), India, and in Sindh, Pakistan. It is divided into ...

and the Andaman and Nicobar group of islands fall in this zone. Generally, the areas having

trap rock Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include basalt, peridotite, diabase, and gabbro.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. ...

or basaltic rock are prone to earthquakes.

Zone 4

This zone is called the High Damage Risk Zone and covers areas liable to MSK VIII. The IS code assigns a zone factor of 0.24 for Zone 4. Jammu and Kashmir,

Ladakh Ladakh () is a region administered by India as a union territory which constitutes a part of the larger Kashmir region and has been the subject of dispute between India, Pakistan, and China since 1947. (subscription required) Quote: "Jammu ...

Himachal Pradesh Himachal Pradesh (; ; "Snow-laden Mountain Province") is a state in the northern part of India. Situated in the Western Himalayas, it is one of the thirteen mountain states and is characterized by an extreme landscape featuring several peaks ...

Uttarakhand Uttarakhand ( , or ; , ), also known as Uttaranchal ( ; the official name until 2007), is a state in the northern part of India. It is often referred to as the "Devbhumi" (literally 'Land of the Gods') due to its religious significance and ...

Sikkim Sikkim (; ) is a state in Northeastern India. It borders the Tibet Autonomous Region of China in the north and northeast, Bhutan in the east, Province No. 1 of Nepal in the west and West Bengal in the south. Sikkim is also close to the Silig ...

, parts of the Indo-Gangetic plains ( North Punjab,

Chandigarh Chandigarh () is a planned city in India. Chandigarh is bordered by the state of Punjab to the west and the south, and by the state of Haryana to the east. It constitutes the bulk of the Chandigarh Capital Region or Greater Chandigarh, which a ...

Western Uttar Pradesh Western Uttar Pradesh is a region in India that comprises the western districts of Uttar Pradesh state, including the areas of Rohilkhand and those where Khariboli, Braj and Kannauji are spoken. The region has some demographic, economic and cul ...

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, a major portion of

Bihar Bihar (; ) is a state in eastern India. It is the 2nd largest state by population in 2019, 12th largest by area of , and 14th largest by GDP in 2021. Bihar borders Uttar Pradesh to its west, Nepal to the north, the northern part of West ...

, North Bengal, the

Sundarbans Sundarbans (pronounced ) is a mangrove area in the delta formed by the confluence of the Padma, Brahmaputra and Meghna Rivers in the Bay of Bengal. It spans the area from the Baleswar River in Bangladesh's division of Khulna to the Hooghly R ...

) and the capital of the country

Delhi Delhi, officially the National Capital Territory (NCT) of Delhi, is a city and a union territory of India containing New Delhi, the capital of India. Straddling the Yamuna river, primarily its western or right bank, Delhi shares borders ...

fall in Zone 4. In Maharashtra, the Patan area (

Koynanagar Koynanagar is a town in Maharashtra, India. It is situated on the Chiplun-Sangli state highway on the banks of Koyna River. The town is small but famous for Koyna Dam and the Koyna Hydroelectric Project which is the largest completed hydroelectri ...

) is also in Zone 4.

Zone 3

This zone is classified as a Moderate Damage Risk Zone which is liable to MSK VII. The IS code assigns a zone factor of 0.16 for Zone 3. Several megacities like

Chennai Chennai (, ), formerly known as Madras ( the official name until 1996), is the capital city of Tamil Nadu, the southernmost Indian state. The largest city of the state in area and population, Chennai is located on the Coromandel Coast of th ...

Mumbai Mumbai (, ; also known as Bombay — List of renamed Indian cities and states#Maharashtra, the official name until 1995) is the capital city of the Indian States and union territories of India, state of Maharashtra and the ''de facto'' fin ...

, Bengaluru,

Kolkata Kolkata (, or , ; also known as Calcutta , the official name until 2001) is the capital of the Indian state of West Bengal, on the eastern bank of the Hooghly River west of the border with Bangladesh. It is the primary business, comme ...

and Bhubaneshwar lie in this zone.

Zone 2

This region is liable to MSK VI or lower and is classified as the Low Damage Risk Zone. The IS code assigns a zone factor of 0.10 for Zone 2. It is the zone with low chances of having earthquakes. Cities like Trichy or Thiruchirappalli are in this zone ,ex- cities of Bulandshahr , Moradabad, Gorakhpur, Chandigarh

Zone 1

Since the current division of India into earthquake hazard zones does not use Zone 1, no area of India is classed as Zone 1,as it is no such thing.

Notes

{{reflist

External links

India Meteorological Department
Zoning Geology of India Emergency management in India Geographic areas of seismological interest Seismology Seismic zones by country