EARTHQUAKES

Published on 23 Feb 2025

An earthquake is a natural phenomenon that occurs when there is a sudden release of energy in the Earth's crust, resulting in ground shaking, trembling, and sometimes the displacement of the Earth's surface.

Vulnerability of India

• Geographical vulnerability

• Tectonic plate boundary: India is situated at the boundary of the Indian Plate and the Eurasian Plate. The collision of these two plates makes the northern region highly susceptible to earthquakes.

• Example: Kashmir earthquake, 2005.

• Subduction zones: The northwestern region of India, including parts of Gujarat and Rajasthan, lies near the subduction zone where the Arabian Plate is converging with the Eurasian Plate.

• Example: Bhuj earthquake, 2001.

• Structural vulnerability: Poor construction practices, inadequate design/engineering standards, non-compliance with building codes, and substandard materials make infrastructure vulnerable to earthquake damage or collapse.

• Example: During the Bhuj earthquake, buildings collapsed or suffered severe damage due to inadequate construction practices and non-compliance with building codes.

• Socio-economic vulnerability: Factors such as high population density, poverty, inadequate infrastructure, limited access to healthcare and emergency services, and lack of awareness and preparedness make people in seismic zones vulnerable.

• Institutional Vulnerability: Includes inadequate preparedness and response capabilities of governments, emergency management agencies, and organizations responsible for disaster management.

Man-made earthquakes

• Reservoir-induced seismicity: The weight of the water in a large reservoir exerts pressure on the underlying rocks, which can induce earthquakes.

• Example: Koyna earthquake, 1967.

• Mining: The removal of large amounts of material from the Earth's crust can cause stress redistribution, leading to the occurrence of mining-induced earthquakes.

• Example: 1989 Newcastle earthquake has been attributed to deep coal mining in the region.

• Hydraulic fracturing (Fracking): Fracking is a method to extract oil/gas from shale rock by injecting high-pressure fluid underground. It can trigger seismic events, especially in faulted areas or with pre-existing stresses.

• Example: Studies link increased seismic activity in Oklahoma (USA) to wastewater disposal from fracking operations into deep underground injection wells.

• Underground nuclear Tests: The energy released by these explosions can generate seismic waves and cause earthquakes.

• Example: North Korean nuclear test in 2006 resulted in a seismic event with a magnitude of approximately 4.3.

Effects of earthquakes

• Economic effects

• Infrastructure damage: Earthquakes can cause severe damage to infrastructure, including buildings, roads, bridges, power lines, and water supply systems. The cost of repairing or rebuilding damaged infrastructure can be substantial.

• Economic losses: Business interruptions, job losses, and damage to industries can lead to significant economic losses following an earthquake.

• Impact on livelihoods: Damage to crops, livestock, and tourist attractions can result in loss of income for individuals and communities.

• Increased government spending: Substantial funds needed for emergency response, rescue and relief operations, and long-term recovery efforts after an earthquake can strain public budgets and impact overall economic development.

• Social effects

• Displacement: Earthquakes can lead to the displacement of people from their homes due to the destruction or severe damage of buildings.

• Disruption of Social Services: Earthquakes can disrupt essential social services, including healthcare, education, transportation, and communication infrastructure.

• Psychological effects: Earthquakes can have lasting psychological effects on individuals, causing anxiety, stress, and trauma. Witnessing the destruction, experiencing personal loss, and living in a state of uncertainty can have a significant impact on mental well-being.

• Environmental effects

• Landslides: Earthquakes can trigger landslides, especially in hilly or mountainous areas.

• Example: Earthquake triggered landslide in Sikkim, 2011.

• Tsunamis: In coastal regions, undersea earthquakes can generate tsunamis, that can cause extensive coastal flooding and damage ecosystems.

• Example: The 2004 Indian Ocean earthquake and tsunami.

• Liquefaction: During earthquakes, certain soils can liquefy (loses their strength and behaves like a liquid). This can result in the sinking, tilting, or collapsing of buildings and infrastructure.

• Example: The liquefaction-induced damage was widespread in parts of Bhuj in the 2001 earthquake.

• Changes in Water Bodies: Earthquakes can cause changes in water bodies such as rivers, lakes, and groundwater systems.

• Example: Assam earthquakes in 1897 and 1950 resulted in significant changes in Brahmaputra River system.

Challenges in mitigation of earthquakes

• Prediction: Earthquakes are complex natural phenomena, and accurately predicting their occurrence and magnitude is challenging. The scientific understanding of earthquakes and the ability to forecast them with precision is still limited.

• Geographical challenges: Most of the earthquake-prone zones are in hilly and mountainous areas. Retrofitting is challenging and expensive in these areas.

• Substandard construction: Many people in India reside in informal settlements or slums, where buildings are often constructed with substandard materials and techniques. These structures are highly vulnerable to earthquakes.

• Financial constraints: Implementing effective earthquake mitigation measures, such as retrofitting existing structures or constructing new buildings to withstand seismic events, can be expensive.

• Socioeconomic factors: Factors, such as poverty, unequal access to resources, and inadequate housing conditions, can hinder effective earthquake mitigation

• Lack of awareness and education: Lack of awareness hampers the adoption of preventive measures and the implementation of building codes and standards.

India’s current preparedness

• NDMA guidelines

• Seismic Strengthening and Retrofitting: While undertaking seismic retrofitting of the critical and lifeline structures, other structures will be insured against losses during future earthquakes.

• Building Codes and Other Safety Codes: State governments/SDMAs will, in consultation with their State Earthquake Management Committees and Hazard Safety Cells, establish the necessary techno-legal and techno-financial mechanisms.

• Compliance review: Designs of all structures will go through a mandatory compliance review by the professionals of the Urban Local Bodies and Panchayati Raj Institutions.

• Public awareness and education: Develop and implement public awareness campaigns to educate the public about earthquake risks, safety measures, and preparedness.

• Capacity building: Enhance the capacity of government agencies, first responders, and local communities in earthquake management through training programs.

• Community Based Disaster Response: State government/SDMAs and District Disaster Management Authority will coordinate several organizations, like NGOs, self-help groups, women’s groups, and volunteer agencies for performing various response activities.

• Institutional framework: Establish coordination mechanisms at the national, state, and local levels to ensure effective earthquake management.

• Institutional measures

• National Centre for Seismology (NCS): The NCS operates under the Ministry of Earth Sciences. It operates a network of seismic monitoring stations, analyzes seismic data, and provides earthquake information to various stakeholders.

• Bureau of Indian Standards (BIS): BIS develops and promotes standards for seismic-resistant construction practices in India. It formulates building codes, design guidelines, and specifications.

• Policy measures

• National Retrofit Program: It is aimed at enhancing the seismic resilience of existing buildings. Retrofitting techniques can include various structural modifications, such as adding shear walls, strengthening foundations, reinforcing beams and columns etc.

• National Building Code (2005): It is a comprehensive set of guidelines and standards for the design, construction, and maintenance of buildings in India.

• Technological measures

• Seismic zoning map: It is given by the BIS. The total area of the country is classified into four seismic zones. Zone V is seismically the most active region, while zone II is the least.

• ‘India Quake’ mobile app: It has been developed by the NCS for automatic dissemination of earthquake parameter (location, time, and magnitude) after the occurrence of earthquakes.

Implementation gaps

• Building codes enforcement: The lack of effective enforcement mechanisms leads to non-compliance with the seismic design requirements.

• Retrofitting of existing structures: There is a lack of widespread retrofitting initiatives in India, particularly for older structures. Limited awareness, financial constraints, and insufficient technical expertise contribute to the slow pace of retrofitting efforts.

• Land use regulations: Rapid urbanization, informal settlements, and inadequate infrastructure complicate the effective implementation of land use planning measures.

• Infrastructure resilience: Limited resources, budgetary constraints, and competing priorities affect the pace and scale of infrastructure resilience initiatives.

Way Forward

• Strengthening Building Codes and Regulations: This includes ensuring the use of appropriate construction materials, reinforcing structures, and implementing rigorous quality control measures during construction.

• Retrofitting Existing Structures: Identify and prioritize vulnerable structures, particularly older buildings and critical infrastructure, for retrofitting to improve their seismic resilience.

• Urban Planning and Land Use Regulations: Incorporate seismic considerations into urban planning and land use regulations to prevent the construction of new buildings in high-risk zones.

• Collaboration and Partnerships: Foster collaboration among different stakeholders, including government agencies, academic institutions, industry experts, and non-governmental organizations, to share knowledge, resources, and best practices.

Best practices

• Japan: Japan has one of the most advanced seismic building codes globally, which require structures to withstand earthquakes. Buildings are designed to absorb seismic energy and have features like base isolation and dampers.

• The USA: It has been developing an earthquake early warning system called ShakeAlert, which provides alerts before significant shaking reaches an area. This system allows individuals and organizations to take immediate protective actions.

Chile: Chile places a strong emphasis on public education and awareness about earthquakes. Schools regularly conduct drills, and public campaigns inform individuals about earthquake risks and preparedness measures.

Tags:
Disaster Management

Keywords:
EARTHQUAKES disaster disaster management earthquake Vulnerability of India Man-made earthquakes Effects of earthquakes Challenges in mitigation of earthquakes India’s current preparedness Best practices to mitigate earthquake

Syllabus:
General Studies Paper 3

Topics:
Disaster and Disaster Management