Human-Induced Earthquakes

Recent studies and seismic data have highlighted the increasing frequency of human-induced earthquakes in India, with significant linkages to groundwater extraction, reservoir loading, and infrastructural activities in seismically vulnerable regions.

Rising Anthropogenic Activities and Seismic Vulnerability: A Case Study of Human-Induced Earthquakes in India

1. Understanding Human-Induced Earthquakes

• Definition and Global Context: Human-induced earthquakes (HIEs) are seismic events triggered by anthropogenic activities. As per Seismological Research Letters (2017), over 700 such events have occurred globally in the last 150 years.
• Mechanism: Activities such as mining, fluid injection, dam construction, and groundwater depletion alter the stress balance along fault lines, potentially triggering seismic events.

2. India-Specific Observations

• Delhi-NCR and Groundwater Depletion: A 2021 study in Scientific Reports linked shallow earthquakes in Delhi-NCR to groundwater extraction between 2003–2012. Seismic activity decreased post-2014 when the water table stabilized.
• Koyna Earthquake (1967): A 3 magnitude quake, caused by water impoundment in the Koyna dam, killed over 180 people and destroyed thousands of houses. This was one of the earliest confirmed instances of a reservoir-induced earthquake (RIE) in India.
• Other Vulnerable Zones:
  • Mullaperiyar Dam (Kerala)
  • Palghar district (Maharashtra)
  • Sahyadri Range (Western Ghats) – showing signs of seismicity induced by extreme rainfall.

3. Anthropogenic Triggers of Earthquakes

• Groundwater Extraction:
  • Depletes sub-surface pressure balance.
  • Increases vertical stress and may activate dormant fault lines.
• Reservoir-Induced Seismicity (RIS):
  • Caused by loading and percolation of water in faulted rock zones.
  • Risk aggravated in tectonically active areas like the Himalayas.
• Fracking and Energy Extraction:
  • India has 56 fracking sites across six states.
  • Injection of fluid causes fissures and displacement, triggering seismic events.
• Construction of Tall Infrastructure:
  • Concentrated loading in high-rise cities in seismically active zones, e.g., Delhi, increases vulnerability.

4. Impact of Climate Change on Seismicity

• Glacial Melting: Observed in Antarctica and Greenland; loss of mass alters stress distribution along tectonic plates.
• Rainfall Variability: Sudden, intense rainfall alters surface pressure and water loading—evident in the Sahyadris.
• Drought and Seismic Reactivation: 2014 California quake attributed to prolonged drought-induced fault reactivation.

5. Scientific and Policy Recommendations:

• Scientific Monitoring:
  • Expand seismic networks across fault-prone regions.
  • Real-time monitoring systems to track fluid migration and stress changes.
• Regulatory Reforms:
  • Enforce controlled dam-filling/emptying protocols, as done in the U.S.
  • Limit fracking and energy projects in seismic zones.
• Groundwater Governance:
  • Encourage rainwater harvesting and managed aquifer recharge.
  • Integrate hydrogeology with urban planning and cropping patterns.
• Environmental Impact Assessment (EIA) Reforms:
  • Mandatory seismic risk assessment for large infrastructure projects.
  • Incorporate climate-induced seismic risk metrics in EIA reports.