UNDERSTANDING RECENT EARTHQUAKE ACTIVITY

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TAG: GS 3: ECOLOGY AND ENVIRONMENT

THE CONTEXT: Recent seismic activity in parts of north India and Nepal has been attributed to the activation of the Almora fault, according to Earth Sciences Minister.

EXPLANATION:

Background Seismicity and Recent Spike

• Consistent Background Seismicity:
  • The Earth Sciences Minister highlighted the steady level of background seismic activity, denoting usual earthquake occurrences, in the regions under scrutiny.
• Recent Spike in Earthquakes:
  • Despite the consistent background seismicity, certain areas in north India and Nepal experienced a surge in seismic events, particularly attributed to the activation of the Almora fault.

Role of Almora Fault in Earthquake Occurrences

• Triggering Significant Earthquakes:
  • The Almora fault, a critical geological structure in the western Himalayas, has played a pivotal role in recent seismic activity.
• Key Mainshocks and Their Magnitudes:
  • Notable earthquakes were reported on January 24 (5.8 magnitude), October 3 (6.2 magnitude), and November 3 (6.4 magnitude), all linked to the Almora fault.
• Geological Significance:
  • The fault line lies adjacent to active faults within the Himalayan region, where the Indian plate subducts under the Eurasian Plate, resulting in frequent seismic occurrences.

Impact and Concerns

• Geographical Impact:
  • The seismic events had a wide-reaching impact, with tremors felt across a significant area.
  • For instance, the January 24 quake centered in Nepal was felt strongly in Delhi, Uttar Pradesh, and Uttarakhand.
• Safety and Preparedness Concerns:
  • The recent activation of the Almora fault has raised concerns regarding regional safety measures and preparedness for potential earthquakes.

Mitigation Efforts and Safety Measures

• Bureau of Indian Standards (BIS) Initiatives:
  • The BIS’s has played an important role in releasing the Seismic Zoning Map of India, categorizing regions into different risk zones (II to V) and offering guidelines for constructing earthquake-resistant structures.
• National Disaster Management Authority (NDMA) Interventions:
  • The NDMA is actively implementing precautionary measures, including earthquake drills, awareness campaigns, and incident management strategies to enhance preparedness and response capabilities in seismic zones.

Lessons and Continued Vigilance

• Aftermath and Aftershocks:
  • The aftermath of the earthquakes, especially the powerful November 3 quake registering a magnitude of 6.4, was marked by more than 382 aftershocks.
  • It emphasized the necessity for continued vigilance and adherence to safety protocols in seismically active regions.
• Regional Safety and Ongoing Concerns:
  • The recent seismic events underscore the ongoing concern for regional safety and the need for sustained efforts in earthquake preparedness and risk reduction strategies.

Conclusion

• The statement by Earth Sciences Minister highlighted the increased seismic activity in specific regions attributed to the activation of the Almora fault.
• By emphasizing the significance of geological structures like the Almora fault and the subsequent impact on safety, the minister underscores the importance of proactive measures, guidelines, and initiatives aimed at mitigating the risks associated with earthquakes and enhancing preparedness in earthquake-prone areas.

SOURCE: https://www.indiatoday.in/science/story/what-led-to-frequent-earthquakes-this-year-earth-sciences-minister-answers-2473074-2023-12-07