1. What is an earthquake? How and where are they formed? what are their consequences ? Explain with examples.
| SYLLABUS: General Studies –I: Important Geophysical Phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc., |
IN NEWS: Earthquake kills over 800 in Afghanistan
An earthquake is a sudden shaking of the Earth’s surface caused by the release of energy stored due to tectonic stresses. These are among the most unpredictable and destructive natural hazards affecting human life, economy, and the environment.
As per the National Center for Seismology (NCS), India experiences hundreds of small to moderate earthquakes annually, with over 59% of its landmass vulnerable to seismic hazards.
1. Formation of Earthquakes:
a) Causes:
1. Tectonic Movements (primary cause)
- Occur due to the movement of Earth’s lithospheric plates.
- Energy builds up at fault lines due to friction and is released suddenly.
- Explained by the Elastic Rebound Theory.
2. Volcanic Activity: Earthquakes near volcanoes due to magma movement.
3. Anthropogenic Activities: Mining, dam reservoirs (e.g., Koyna, Maharashtra), hydraulic fracturing.
b) Zones of Formation:
1. Global Seismic Zones:
- Circum-Pacific Belt (Ring of Fire): 80% of global quakes.
- Alpide Belt: Includes Himalayas, Iran, Turkey.
- Mid-Atlantic Ridge: Divergent plate boundary.
2. India’s Seismic Zoning (Bureau of Indian Standards – BIS):
- Zone V (Very High Risk): NE states, Kashmir, Himachal.
- Zone IV: Delhi, Haryana, Bihar.
- Zone III & II: Central and Southern India.
India lies at the collision boundary of the Indian and Eurasian plates, making the Himalayan region highly seismic.
2. Consequences of Earthquakes
a) Humanitarian Impact:
- Massive loss of life, injuries, psychological trauma.
- Displacement and migration of vulnerable populations.
b) Economic Consequences:
- Damage to homes, infrastructure, industries.
- Example: Bhuj Earthquake (2001) – ₹15,000+ crore economic loss.
c) Environmental Effects:
- Trigger landslides (e.g., 2015 Nepal Earthquake)
- Tsunamis (e.g., 2004 Indian Ocean Tsunami)
- River course changes
d) Social & Political Challenges:
- Rehabilitation, governance breakdown in emergencies
- Stress on emergency services
3. Case Studies & Recent Examples
Afghanistan Earthquake (October 2025)
- Magnitude: 6.4
- Location: Western Afghanistan, near Herat
- Casualties: Over 1,500 deaths, thousands injured
- Damage: Extensive collapse of traditional mud houses
- Reason: Tectonic collision of Indian and Eurasian plates
India’s Ministry of External Affairs expressed condolences and offered humanitarian aid. This event highlights seismic vulnerability in under-prepared regions with poor infrastructure.
Delhi-NCR Earthquake Swarms (2025)
- 17+ minor earthquakes by July 2025 (highest in a decade).
- Most were shallow-focus (<10 km) leading to strong surface tremors.
- Structural vulnerability in pre-2000 buildings poses severe risks.
Myanmar Earthquake (April 2025)
- Magnitude 7.7 on Sagaing Fault.
- India launched Operation Brahma: sent NDRF, medical teams, and field hospitals.
Bhuj Earthquake (2001)
- Magnitude: 7.7 | Deaths: ~13,800
- Led to creation of Smritivan Earthquake Memorial, a symbol of resilience.
4. Institutional & Policy Response (India)
a) National Disaster Management Framework
| Institution | Role |
| NDMA (2005) | Earthquake risk reduction guidelines, retrofitting policy |
| NIDM | Capacity building and training |
| IMD/NCS | Earthquake monitoring & seismological data |
| BIS | Seismic Zoning Maps & Building Code (IS 1893) |
b) Government Schemes & Initiatives
- National Earthquake Risk Mitigation Project (NERMP): Capacity building, retrofitting, policy formulation.
- Smart Cities Mission: Integrates seismic vulnerability into urban planning.
- PMAY (Urban & Gramin): Promotes disaster-resilient housing.
- School Safety Programme (UNDP-NDMA): Seismic retrofitting and mock drills.
c) Technological Interventions
- Seismic monitoring stations increased from 80 (2014) to 168 (2024).
- Earthquake Early Warning System: Implemented in Uttarakhand, to be expanded nationally.
- GIS-based hazard zoning and satellite mapping (ISRO + MoES).
5. Challenges & Way Forward
| Challenges | Way Forward |
| Poor enforcement of seismic codes | Strengthen compliance through ULBs and state agencies |
| Lack of retrofitting in old buildings | Incentivize and subsidize retrofitting |
| Low community preparedness | Expand school/community-level disaster awareness |
| Insufficient monitoring in remote areas | Expand seismograph networks & sensor density |
| Rapid urbanization in seismic zones | Integrate risk maps into urban planning (SDG 11) |
Earthquakes, though natural, turn disastrous due to human vulnerability. With the increasing frequency of seismic events in South Asia—as shown by the 2025 Afghanistan earthquake—it is critical to transition from reactive to proactive seismic risk management. Scientific monitoring, resilient infrastructure, community awareness, and international cooperation form the pillars of earthquake disaster resilience.
| PYQ REFERENCE: (2025) Q. What are Tsunamis? How and where are they formed? What are their Consequences? Explain with examples. |
2.”Despite years of policy interventions, India continues to grapple with hazardous levels of air pollution, especially in the Indo-Gangetic Plain. Discuss the key causes, consequences, and suggest long-term mitigation strategies in the light of the Air Quality Life Index (AQLI) 2025 findings.”
| SYLLABUS: General Studies –III: Conservation, Environmental Pollution and Degradation, Environmental Impact Assessment. |
IN NEWS: All of India breathes bad air, AQLI 2025 report says
Air quality in India is bad by its own standards, which are more lenient. According to the report, 46% of Indians live in areas where the PM2.5 standard of 40 g/m3 has been breached
1. Causes of Persistent Air Pollution in India:
a) Anthropogenic Emissions:
- Vehicular emissions: Poor public transport, old diesel vehicles.
- Industrial pollution: Especially brick kilns, thermal power plants.
- Construction dust: Weak enforcement of dust-control norms.
- Residential heating: Biomass and coal-based cooking in rural/urban fringes.
b) Agricultural Practices: Stubble burning in Punjab, Haryana → Seasonal spikes in PM2.5 in North India.
c) Meteorological & Topographical Factors:
- Temperature inversion in winter traps pollutants.
- Himalayan barrier prevents dispersion of air masses.
- The Indo-Gangetic basin acts like a “pollution bowl”.
d) Cross-border Pollution: Pollution from Bangladesh, Nepal, and Pakistan adds to regional haze (AQLI 2025 confirms transboundary nature).
e) Policy-Implementation Gap: Many policies exist (e.g., National Clean Air Programme), but execution and monitoring remain weak.
2. Consequences of Air Pollution (As per AQLI 2025)
- Health: India’s population is exposed to PM2.5 levels ~9x WHO limit; the average Indian could gain 5.3 years of life if pollution is reduced to WHO norms.
- Economy: Productivity loss, increased healthcare burden (estimated ₹3 lakh crore/year by WB).
- Environment: Damage to crops (ozone exposure), acid rain, degraded soil and water bodies.
- Social Equity: Poorer populations suffer more (indoor cooking smoke, congested housing).
- Children & Elderly: Higher incidence of asthma, bronchitis, developmental issues.
3. Global Comparisons: Lessons from China (AQLI 2025)
- Despite a 2.8% rise in 2023, China has reduced PM2.5 by 40.8% since 2014.
- Measures taken:
- Phased out old coal plants
- Restricted private vehicles in major cities
- Shifted home heating from coal to electric/gas
- Strict real-time monitoring and enforcement
4. Government Measures in India:
a) Policy Interventions:
- National Clean Air Programme (NCAP) – 2019: 20-30% reduction in PM2.5 by 2024 (extended to 2026); covers 131 cities.
- Commission for Air Quality Management (CAQM): Statutory body for NCR; regulates seasonal burning, industrial pollution.
- Faster Adoption and Manufacturing of Electric Vehicles (FAME): Reduction in vehicular emissions.
- BS-VI Emission Norms: Introduced in 2020 to curb vehicular pollutants.
- Ujjwala Yojana Clean: LPG access to reduce indoor air pollution.
b) Technological Solutions:
- Smog towers in Delhi (pilot stage, mixed results)
- Green buffers and plantation drives
- Air Quality Monitoring Systems (CPCB, SPCBs)
- Satellite-based stubble detection via ISRO
5. Long-Term Sustainable Strategies:
- Urban Transport:Expand metro rail, e-buses, cycling infrastructure
- Clean Energy: Phase out coal plants near urban centers; solar rooftop push
- Agriculture: Incentivize no-burn technologies (e.g., Happy Seeder)
- Building Regulations: Enforce dust norms, green buildings
- Behavioral Change: Citizen participation via awareness (like ‘CleanAirForAll’)
- Cross-Border Collaboration: Regional SAARC/BBIN pollution management treaty
The AQLI 2025 reaffirms what India has long grappled with: air pollution is the single largest external threat to human health. Despite decades of policies, the Indo-Gangetic plain remains a hotspot. What is needed now is a coordinated national mission, similar in scale to the Swachh Bharat Abhiyan, that focuses on clean air as a fundamental right, backed by technology, governance, and public accountability.
| PYQ REFERENCE (2021) Q.Describe the key point of the revised Global Air Quality Guidelines [AQGs] recently released by the World Health Organisation [WHO].How are these different from its last update in 2005? What changes in India’s National Clean Air Programme are required to achieve these revised standards ? |