Which of the following can be the reasons behind the number of earthquakes in Delhi in recent times? 

1. Closeness to main boundary thrust fault.

2. Movement of the Indian tectonic plate.

3. Loose soil in the Ganga Alluvial Plain.

4. Presence of many weak zones and faults.

Select the correct answer using the code given below:

Solution

Option 1 is correct. Delhi is located within a distance of 200-400 km from diff erent locations of the main boundary thrust fault. The main boundary thrust fault of the Himalayas, which runs from Kashmir to Arunachal Pradesh, is highly active. Option 2 is correct. Earthquakes in Delhi-NCR were due to the “release of stress” accumulated from the movement of the Indian tectonic plate and its collision with the Eurasian tectonic plate. Option 3 is incorrect. The “large sediment thickness (loose soil) in the Ganga Alluvial Plains” to the north of Delhi t ends to amplify the impact of earthquakes. It is not directly responsible for the generation of earthquakes. Option 4 is correct. There are so many weak zones and faults in the Delhi-NCR: - Delhi-Haridwar ridge, Mahendragarh-Dehradun subsurface fault, Moradabad fault, Sohna fault, Great boundary fault, Delhi-Sargodha ridge, Yamuna River lineament, Ganga River lineament etc.