At least 38 Indian cities lie in high-risk seismic zones; nearly 60% of the subcontinental landmass is vulnerable to earthquakes and except for rare exceptions—such as the Delhi Metro—India’s hastily-built cities are open to great damage from earthquakes.
The earthquake that devastated the Kathmandu Valley in Nepal and jolted northern India, damaging buildings as far apart as Agra and Siliguri, was expected by geologists, who have warned of more Himalayan earthquakes, caused by the growing pressures of the subcontinent grinding into the Asian mainland.
You may or may not have felt the tremors of recent earthquakes but do you know how safe you are in your home and office when a major earthquake (I hope it should never) hits your city. Its good to buy an apartment in a high rise building with a superb view from top floors but have you taken the earthquake safety into consideration.
India is very prone to earthquakes. The major reason for the high frequency and intensity of the earthquakes is that the Indian plate is driving into Asia at a rate of approximately 47 mm/year. According to the estimates shown by a World Bank and United Nations report; around 200 million city dwellers in India will be exposed to storms and earthquakes by 2050.
Gujarat and Uttar Pradesh appear to be the most vulnerable states, with six cities each in earthquake- prone zones. Both the states have one city each under zone IV and five cities marked under zone III. Maharashtra is next with four cities in zone III.
The Bureau of Indian Standards [IS-1893 – part – 1: 2002], based on scientific inputs from a number of agencies, including earthquake data supplied by Indian Meteorological Department (IMD), has grouped India into four seismic zones, II, III, IV and V.
The Modified Mercalli (MM) intensity scale, which measures the impact of earthquakes on the surface of the earth, is broadly associated with India’s earthquake zones, as follows:
|Intensity Of Earthquakes In Different Zones|
|Seismic Zone||Intensity on Modified Mercalli scale||% Of Total Area|
|Zone II (Low intensity zone)||VI (or less)||43|
|Zone III (Moderate intensity zone)||VII||27|
|Zone IV (Severe intensity zone)||VIII||18|
|Zone V (Very severe intensity zone)||IX (and above)||12|
Zone 5 is highly prone to the earthquake with the highest level of seismicity whereas Zone 2 is associated with the lowest level of seismicity. So, the Zones – marked two to five -indicate areas most likely to experience tremors with five being the most vulnerable.
Indian cities, ranging from the metros to the smaller cities – all at least once have been shaken up due to earthquakes which usually range from medium to high intensity on the Richter scale.
With some research we present you the top 10 Indian cities which are observed as high earthquake prone zones:
1. Guwahati – Assam
Guwahati falls in zone five of the seismic zones in India which is highly prone to earthquakes. The place has seen some of the deadliest earthquakes and even today small tremors are a common situation. Guwahati receives earthquake predictions on a daily basis; resulting which many adjoining areas in the North-East get affected.
2. Srinagar – Jammu and Kashmir
This capital city of Jammu and Kashmir also comes under Seismic Zone 5.
Most parts of the Kashmir Valley, which is around 11% of the area of the state covering the Districts of Srinagar, Ganderbal, Baramulla, Kupwara, Bandipora, Budgam, Anantnag, Pulwama, Doda, Ramban, Kishtwar, come under Seismic Zone 5, where around 50% of the population of the state lives. The rest of the state, including the whole of the Ladakh region and Jammu Division (90% of the total area of the state), are under the Seismic Zone 4.
Being very close to the Himalayas, Srinagar faces heavy risk of earthquakes, high as well as moderate. The friction between the Indian and the Eurasian plane causes earthquakes to occur on the areas close to the Himalayas.
Delhi is categorised under Seismic Zone 4.
Delhi has been hit by five devastating earthquakes measuring higher than magnitude of 5 since 1720. The most prone to earthquake neighbourhoods in Delhi lie about two miles on either side of the Yamuna river, the southwestern outskirts of the city known as the Chhattarpur basin, as well as an area popularly known as The Ridge in Delhi.
4. Mumbai – Maharashtra
Mumbai falls in the Zone 4 of the seismic zone divisions which makes it quite vulnerable to damage.
We all know Mumbai is located on the coastal line, which increases the risk of facing tsunami-like disasters. Mild to strong earthquakes are very common in parts of Mumbai. Mild earthquakes are often faced by people living there and parts of the adjoining regions of Gujarat. It should be noted that for the last 20 years, almost all of the buildings in Mumbai have been designed and built keeping in mind that the city falls in seismic zone 4.
5. Chennai – Tamil Nadu
The city, formerly in the comfort Zone 2, has now shifted to Zone 3 – indicating higher seismic activity. According to the seismic mapping , districts in the western part along the border with Kerala are also in Zone 3, along with districts along the border of Andhra Pradesh and a section of the border with Karnataka.
The status of Chennai along with major towns on the eastern coast in terms of vulnerability has increased especially after Chennai experienced tremors in September 2001 following a quake measuring 5.6 on the Richter scale off the Pondicherry coast.
Tamil Nadu, had faced the wrath of the deadly 2004 tsunami when the Marina beach was affected.
Recently, in the year 2012, Chennai shook terribly due to a rather high intensity earthquake (having its epicentre in the Indian Ocean).
The other 5 cities in right order of chronology are:
6. Pune – Maharashtra
7. Kochi – Kerala
8. Kolkata – West Bengal
9. Thiruvananthapuram – Kerala
10. Patna – Bihar
History serves warning that a big one may come at any time. Those lessons come from Bihar in 1934 and Assam in 1950.
Although its epicentre was 10 km south of Mount Everest, the Bihar earthquake of 1934 was felt from Mumbai to Lhasa, flattening almost all major buildings in many Bihar districts and damaging many in Calcutta. At 8.4 on the Richter scale, it was pretty severe, killing more than 8,100 (Mahatma Gandhi said it was punishment for the sin of untouchability).
The 1950 Assam earthquake, may have geologically set the stage for a really big one in the Himalayas, according to geologists. Now that 65 years have passed, it may be time for a big one.
“India has had five moderate earthquakes (Richter Magnitudes ~6.0-6.4) since 1988 as reminders to improve the earthquake preparedness of the country. And, historically, some of the great earthquakes (Richter Magnitudes >8.0) have occurred in India and that too four in the last 115 years,” a professor at the Indian Institute of Technology (Kanpur), wrote in 2000.
The world seismic community has taken advantage of the experiences from these events, but we in India have paid no heed to these reminders. Today, the number of persons interested in improving the earthquake preparedness in the country is effectively very small. Moreover, most of these persons are in the academia.
Source: National Disaster Management Authority. GOI
Image Source: NDMA