How will Indian Cities Fare if a Turkey-like Earthquake Strikes the Subcontinent?

On 6 February, 2023 Southern Turkey and the adjoining areas in Syria were hit by a 7.8 magnitude earthquake followed by several aftershocks. The tremors have flattened buildings and destroyed roads and other infrastructure. At least 35,000 casualties (UPDATE) have occurred across Turkey and Syria, with the vast majority being in the former nation. A news report cited the Turkish environment minister saying that 24,921 buildings across the region had collapsed.

What would happen if a similar tragedy were to strike India? Are Indian cities any better prepared? How many major Earthquakes have occurred in India and what was the death toll? How many seismic zones are there in India? What are Indian construction standards and guidelines when it comes to earthquake resistant buildings? Are there any manuals or documents to disseminate information to the public?    

How vulnerable is India to Earthquakes?

India lies at the northwestern end of the Indo-Australian Plate, which encompasses India, Australia, a major portion of the Indian Ocean. This plate is colliding against and going under the Eurasian Plate in a process called subduction. A seismic zone map prepared in 1970 subdivided India into five zones: I, II, III, IV and V, arranged in ascending order to severity. The intensity in each of these zones is V or less (moderate), VI (strong), VII (very strong), VIII (severe), and IX and higher (violent) respectively, as per the modified Mercalli intensity scale.   

Source: Learning Earthquake Design and Construction, C.V.R Murty, Indian Institute of Technology, KanpurSource: Learning Earthquake Design and Construction, C.V.R Murty, Indian Institute of Technology, Kanpur

The Bureau of Indian Standards re-classified India into four seismic zones in 2002 by merging zone I into zone II. An Indian Express news report states that according to the Ministry of Earth Sciences, Zone V includes Northeastern India, parts of Jammu and Kashmir and Himachal Pradesh, Uttaranchal, Rann of Kutch in Gujarat, parts of North Bihar and Andaman & Nicobar Islands.

Zone-IV includes the remaining parts of Jammu and Kashmir and Himachal Pradesh. Delhi-NCR region, Sikkim, northern parts of Uttar Pradesh, Bihar and West Bengal, parts of Gujarat and small portions of Maharashtra near the west coast and Rajasthan also fall in this zone.

Regions under zone III are Goa, Kerala, Lakshadweep, remaining parts of Uttar Pradesh, Gujarat and West Bengal, parts of Punjab, Rajasthan, Madhya Pradesh, Bihar, Jharkhand, Chhattisgarh, Maharashtra, Orissa, Andhra Pradesh, Tamilnadu and Karnataka.

The remaining portion of the country falls under zone II.

What are the major earthquakes India has experienced?

According to a document prepared by the National Disaster Management Agency there were six major earthquakes that struck India between 1990 and 2006. These were:

•    The Uttarkashi earthquake of 1991.
•    The Latur earthquake of 1993.
•    The Jabalpur earthquake of 1997.
•    The Chamoli earthquake of 1999. 
•    The Bhuj earthquake of 26 January 2001 
•    The Jammu & Kashmir earthquake of 8 October 2005.

The death toll from these earthquakes is estimated at 26,000 people, apart from enormous damage to public property and infrastructure. 
 
 
Source: Learning Earthquake Design and Construction, C.V.R Murty, Indian Institute of Technology, Kanpur

What are the government agencies tasked with setting guidelines for natural disasters?

The National Disaster Management Authority, which functions under the Prime Minister, is the apex body for disaster management. In 2007 it released a document titled ‘Guidelines on Management of Earthquakes’. It states that India’s high earthquake risk and vulnerability is evident from the fact that about 59 per cent of India’s land area could face moderate to severe earthquakes. It added that there were 6 major earthquakes between 1990 and 2006 and that “All these major earthquakes established that the casualties were caused primarily due to the collapse of buildings”. The report makes the following points:

•    All these six major earthquakes established that the casualties were caused primarily due to the collapse of buildings.
•    The occurrence of several devastating earthquakes in areas hitherto considered safe from earthquakes indicates that the built environment in the country is extremely fragile.
•    Our ability to prepare ourselves and effectively respond to earthquakes is inadequate.
•    High intensity earthquakes in the United States and Japan do not lead to such enormous loss of lives, as the structures in these countries are built with structural mitigation measures and earthquake-resistant features.
•    This emphasises the need for strict compliance of town planning bye-laws and earthquake-resistant building codes in India.

And what do the guidelines say?

They have been prepared to reduce the risk and impact of earthquakes, while recognizing that there are enormous challenge in improving seismic safety because of the inadequate numbers of trained and qualified civil engineers, structural engineers, architects and masons proficient in earthquake-resistant design and construction of structures. 

•    The Need for Making All New Constructions Earthquake-Resistant
•    Need for Seismic Strengthening of Existing Structures: There are approximately 12 crore buildings in seismic Zones III, IV and V. Most of these buildings are not earthquake-resistant and are potentially vulnerable to collapse in the event of a high intensity earthquake. The NDMA recommends structural safety audits and retrofitting of select critical lifeline structures and high priority buildings.
•    Building Codes and Other Safety Codes: State governments/State Disaster Management Authorities will establish the necessary techno-legal and techno-financial mechanisms. State governments will also review, revise and update town and country planning Acts, land use and zoning regulations. 
•    Public Awareness: Public awareness materials like brochures, manuals, booklets, action plans, videos, and demonstration kits will be developed for creating public awareness on this subject. Such materials will be fine-tuned by the state governments/SDMAs to suit local needs. 

There are other NDMA authored documents pertaining to earthquakes. For instance the ‘Earthquake Preparedness Guide’ in Hindi and English is an illustrated ready reckoner for home dwellers with Dos and Don’ts. There is also a document with a compilation of all the material collated for different stakeholders and a seismic vulnerability assessment of buildings in India. 

A report by the Delhi Disaster Management Authority prepared in October 2022 states that “Pockets with high rise buildings or ill-designed high-risk areas exist without specific consideration of earthquake resistance. Similarly, unplanned settlements with sub-standard structures are also prone to heavy damage even in moderate shaking”. It further adds that “The Central Business District namely Connaught Place, numerous District Centres and sprouting high rise group housing schemes are high risk areas due to the vertical as well as plan configurations. The walled city area, the trans-Yamuna area, and scattered pockets of unplanned settlements also figures as high risk zones due to their substandard structures and high densities”.

Bureau of Indian Standards: The BIS is the national standards body of India. It formulated two standards, IS 1893:1984, a design standard for designing earthquake resistant buildings, elevated structures, bridges, concrete, masonry and earth dams. Standard No. IS 4326:1993 deals with the selection of materials, special features of design and construction for earthquake resistant buildings. 

What is the Current state of building stock?

According to the Delhi Disaster Management Authority, although the first code of practice for earthquake resistant design was developed in India as early as 1930's after the 1935 Quetta earthquake till date there is no legal framework to require constructions in Delhi must implement seismic code provisions. “The results is that most buildings in Delhi may not meet codal requirements on seismic resistance. Moreover, even if from now on we somehow ensure that all new construction will be earthquake resistant, there still will remain a very large inventory of old buildings that will be deficient for seismic safety. We need to develop a rational seismic retrofitting policy, first for the government- owned buildings and later for the private constructions”.

References:
Guidelines on Management of Earthquakes, released in April 2007, National Disaster Management Authority, click here to access 

An Earthquake Preparedness Guide, National Disaster Management Authority, click here to access 

Matrix of IEC material for earthquake Safety and Preparedness, National Disaster Management Authority, click here to access 

Seismic Vulnerability Assessment of Building Types in India, a Technical document prepared by the Seismic Vulnerability Assessment Project Group, Indian Institutes of Technology, click here to access 

Learning Earthquake Design and Construction, authored by C.V.R. Murty, Indian Institute of Technology Kanpur, sponsored by Building Materials and Technology Promotion Council, New Delhi, click here to access 

Turkey steps up collapse buildings investigation, Reuters,  12 February, 2023, click here to access 

High Risk Seismic Zones in India: How Prone is your city to Earthquakes? The Indian Express, September 21, 2017, click here to access 

Earthquakes, Delhi Disaster Management Authority, October 2022, click here to access

Earthquake Resistant Design and Construction of Buildings – Code of Practice, Bureau of Indian Standards, IS 4326:1993, reaffirmed 2008, click here to access

IS 1893:1984 Criteria for Earthquake Resistant Design of Structures, Bureau of Indian Standards, reaffirmed 2018, click here to access

Image Courtesy: Search and rescue operations continue, in the aftermath of a deadly earthquake in Kahramanmaras, Turkey | Reuters/The Week