RAS question
Northeast India, where the January 5 earthquake occurred, lies in which seismic zone?
Correct answer: (D) Seismic Zone V.
Northeast India lies in Seismic Zone V, the highest seismic-hazard zone in India.
Explanation
Northeast India falls in Seismic Zone V. The Central Water and Power Research Station Annual Report 2014-15, while discussing seismic design ground motion for the Loktak project, states that the entire Northeast India is included in Zone V of India's seismic zoning map and calls it the most severe seismic zone in the country. The region's high seismic hazard is tied to major plate interactions, with Indian-Eurasian plate collision being a key reason. Therefore, for a question asking the seismic zone of the January 5 earthquake region in Northeast India, the answer is Zone V, not a lower-risk zone.
Why the other options are wrong
- (A) Seismic Zone III is wrong because the entire Northeast India is in Zone V, not in this lower seismic zone.
- (B) Seismic Zone II is wrong because it is not the zone assigned to Northeast India in the seismic zoning statement.
- (C) Seismic Zone IV is wrong because Northeast India is Zone V, the most severe zone, rather than Zone IV.
Concept
This tests India's seismic zonation, especially the location of high-risk Himalayan and Northeast regions. It recurs in RAS because earthquakes link physical geography, disaster management and infrastructure planning.