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 death toll from these earthquakes is estimated at 26,000 people, apart from enormous damage to public property and infrastructure.
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.
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
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.
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”.
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
Tagged with: Bureau of Indian Standards Delhi Disaster Management Authority Disaster Preparedness Earthquake India National Disaster Management Authority Seismic Zones Turkey