Context:
- Following recent earthquakes in the Aegean Sea (Turkey–Greece region), mysterious lights observed in the sky have been identified as Earthquake Lights (EQLs).
Key Highlights:
- Scientific Principle / Phenomenon
- Earthquake Lights (EQLs) are flashes, streaks, glowing orbs, or pillars of light seen:
- Before, during, or after earthquakes.
- They occur due to electrical activity in stressed rocks.
- Formation Mechanism
- Tectonic movements cause stress and friction in Earth’s crust.
- Rocks (especially containing quartz or specific minerals) generate electrical charges under pressure.
- These charges:
- Travel through fault lines and cracks.
- Reach the surface and ionise air molecules.
- Ionisation creates plasma-like glowing lights without heat or fire.
- Geological Conditions
- More common in areas with:
- Vertical or straight faults
- Rift zones (easy pathways for electric discharge)
- Significance / Observations
- Rare and not fully understood phenomenon.
- Can serve as possible indicators of seismic activity (though not reliable predictors).
Relevant Prelims Points:
- Earthquake Basics:
- Caused by movement of tectonic plates.
- Energy released as seismic waves.
- Faults:
- Fractures in Earth’s crust where movement occurs.
- Quartz Properties:
- Exhibits piezoelectric effect (generates electric charge under stress).
- Ionisation:
- Process where atoms lose/gain electrons, forming charged particles (plasma).
- Rift Zones:
- Regions where tectonic plates move apart (e.g., East African Rift).
Relevant Mains Points:
- Scientific Importance
- Helps understand electromagnetic phenomena linked to earthquakes.
- Opens avenues for interdisciplinary research (geology + physics).
- Disaster Management Perspective
- Though not reliable predictors, studying EQLs may contribute to:
- Early warning research frameworks.
- Improved understanding of pre-seismic signals.
- Challenges
- Lack of consistent observation and scientific consensus.
- Difficult to distinguish from other atmospheric phenomena (auroras, lightning).
- Way Forward
- Increase instrument-based monitoring of seismic zones.
- Promote global collaboration in geophysical research.
- Integrate findings with earthquake prediction studies cautiously.
UPSC Relevance:
- GS Paper 1: Geography (Earthquakes, Geophysical Phenomena)
- GS Paper 3: Disaster Management, Science & Technology
- Prelims: Earthquake mechanism, Faults, Ionisation, Piezoelectric effect