THE CONTEXT: India’s demand for groundwater, reservoir storage and unconventional hydrocarbons is rising sharply. These activities change the stress field in the upper crust and can trigger human-induced earthquakes. Globally more than seven hundred such events have been catalogued since the late nineteenth century, and the frequency is increasing.
THE BACKGROUND:
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- The 1967 Koyna earthquake of magnitude 6.3, linked to impoundment of the Koyna reservoir, killed about one hundred and eighty people and remains the world’s largest and best-documented case of reservoir-induced seismicity.
- Subsequent Indian examples include low-magnitude swarms around the Mullaperiyar and Idukki reservoirs in Kerala and around the Bhatsa and Warna reservoirs in Maharashtra.
CONCEPTUAL FRAMEWORK (WHAT–WHY–HOW):
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- What: A human-induced earthquake is one whose timing or magnitude is significantly altered by anthropogenic loading or unloading of the crust, fluid injection or extraction, or surface construction.
- Why: Changes in pore pressure and mass perturb the effective normal stress on pre-existing faults. When the stress drop reaches a critical threshold, a slip event occurs.
- How: Typical mechanisms are reservoir-induced seismicity, groundwater withdrawal, hydrocarbon extraction including hydraulic fracturing, high-rise loading on soft sediments and deep wastewater reinjection.
GLOBAL EVIDENCE AND LESSONS:
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- Oklahoma’s shale-gas province recorded more than eight hundred magnitude three-plus events after large-volume wastewater injection.
- Norway’s Alta and China’s Zipingpu dams show that staged filling and controlled drawdown reduce seismic response.
- The United States Geological Survey recommends a traffic-light system that halts industrial operations once ground motion exceeds predefined limits.
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- Fifty-one per cent of administrative units are semi-critical to over-exploited for groundwater (CGWB 2023).
- Reservoirs store more than 250 billion cubic metres of water across six hundred and fifty major and medium dams.
- Hydraulic fracturing is planned or under way at fifty-six sites in six water-stressed States.
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INDIAN EVIDENCE AND VULNERABILITY MAP:
| Region | Anthropogenic driver | Maximum observed magnitude |
|---|---|---|
| Koyna–Warna, Maharashtra | Reservoir level oscillations | 6.3 (1967) |
| Delhi National Capital Region | Groundwater overdraft | 4.5 (2011) |
| Gangetic plains (UP–Bihar–WB) | Aquifer depletion >0.3 m yr⁻¹ | Microseismic swarms ≤3.5 |
| Mullaperiyar–Idukki, Kerala | Reservoir loading and rainfall infiltration | 4.3 (2012) |
| Cambay and Krishna–Godavari basins | Hydraulic fracturing at fifty-six sites in six States | Nil >3 so far |
Delhi lies in Seismic Zone IV and hosts thick unconsolidated alluvium that amplifies ground motion. Similar conditions exist in Patna, Kanpur and Lucknow.
THE DRIVERS:
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- Water stress: Fifty-one per cent of India’s assessed administrative units are semi-critical to over-exploited for groundwater. Average decline in the Indo-Gangetic plain is thirty centimetres per year.
- Aggressive reservoir operation: Fast filling and drawdown cycles to meet peaking power demand increase Coulomb stress on basement faults.
- Unconventional hydrocarbons: Shale-gas pilots involve high-pressure fluid injection in already stressed cratonic basins.
- Vertical urbanisation: Delhi–NCR has added over three hundred high-rise structures since 2005, imposing static loads on compressible alluvium.
- Climate variability: Intensifying monsoon bursts and prolonged droughts alternately load and unload catchments, modulating pore pressure.
POLICY AND REGULATORY LANDSCAPE:
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- Seismic zoning: Bureau of Indian Standards draft IS:1893 (2024) maintains four zones but introduces site-specific design spectrum up to ten-second natural period.
- Disaster management doctrine: National Disaster Management Authority guidelines (2024) emphasise multi-hazard microzonation and resilient lifeline infrastructure.
- Groundwater governance: Central Ground Water Authority notification (2023) mandates digital flowmeters and piezometers for major extractors, yet enforcement remains weak.
- Dam safety: Dam Safety Act 2021 and Central Water Commission reservoir operation manuals lack explicit seismic traffic-light protocols.
THE CHALLENGES:
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- Fragmented monitoring: Only one thousand five hundred digital seismometers feed into the National Seismological Network, leaving gaps in high-risk basins.
- Data opacity: Private well owners and energy companies seldom share real-time extraction or injection data.
- Regulatory overlap: Groundwater, mining, petroleum and river-valley projects fall under different ministries, leading to siloed decision-making.
- Fiscal moral hazard: States favour short-term electricity, or irrigation gains over long-term seismic safety.
- Capacity deficits: District disaster management plans rarely include induced-seismicity scenarios or evacuation drills.
THE WAY FORWARD:
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- Densify seismic networks: The Ministry of Earth Sciences should add five hundred broadband stations in aquifer hot-spots and around large reservoirs. Data must stream to an open-access portal for real-time risk analytics.
- Adopt a traffic-light protocol for dams and fracking: Reservoir filling rates should not exceed one metre per day in seismically sensitive zones. Automatic alarms must suspend injection when peak ground acceleration crosses a threshold set by the Bureau of Indian Standards.
- Mandate integrated water-energy planning: Environmental impact assessments need a coupled hydro-mechanical model that quantifies seismic hazard before licence approval. The model outcomes should guide permissible extraction volumes.
- Implement aquifer recharge credits: Farmers and industries that recharge more water than they extract receive tradable credits under the Atal Bhujal Yojana. This will align groundwater economics with seismic safety.
- Enforce zonal building restrictions: Municipalities in Zone IV and Zone V must prohibit new high-rises on soft sediment without raft-pile foundations vetted by geotechnical audits.
- Strengthen dam instrumentation: All major reservoirs should install continuous GPS, tilt-meters and pore-pressure gauges to detect crustal response. The data should inform adaptive reservoir operation curves.
- Promote climate-resilient catchment management: Reforestation and lake revival upstream of dams reduce rapid inflow peaks that destabilise reservoir levels. Such nature-based solutions complement engineering measures.
- Issue seismic risk bonds: States can transfer part of their contingent liability by issuing catastrophe bonds linked to an induced-seismicity index. The proceeds will fund retrofitting of critical lifelines.
- Support alternative energy portfolios: Accelerating solar and wind in water-stressed regions reduces pressure on hydropower expansion in seismic hot-spots. Fiscal instruments like accelerated depreciation can aid adoption.
THE CONCLUSION:
India cannot afford to postpone decisive action on anthropogenic seismicity. Scientific surveillance, prudent resource management and people-centric governance together will minimise avoidable quakes while securing water and energy for development. Risk-informed choices today will avert humanitarian and fiscal shocks tomorrow.
UPSC PAST YEAR QUESTION:
Q. Dam failures are always catastrophic, especially on the downstream side, resulting in a colossal loss of life and property. Analyze the various causes of dam failures. Give two examples of large dam failures. 2023
MAINS PRACTICE QUESTION:
Q. Human-induced earthquakes highlight the unintended consequences of meeting water and energy needs in India. Discuss.
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