Earthquake in Delhi: Key Insights

Recent Earthquake Event

• Delhi experienced a magnitude 4 earthquake, which was notable for being the strongest to have originated in the city in at least five years.
• The epicenter was near the Dhaula Kuan area, and no significant damage was reported.
• This contrasts with typical tremors in Delhi, often originating from distant locations like Afghanistan.

Seismic Activity and Zone Classification

• Delhi is classified under Zone 4 on India's official earthquake hazard map, indicating a high susceptibility to seismic activity.
• The Medvedev-Sponheuer-Karnik (MSK) scale assesses intensity and places Delhi at a vulnerability level susceptible to major damage (MSK-8).
• Zone 5, the most vulnerable areas, are susceptible to MSK-9 intensity or higher.

Geological Context: Aravalli-Delhi Fold Belt

• Delhi is part of the seismically active Aravalli-Delhi Fold Belt, characterized by deformed rock layers.
• This region has historically been more active, but tectonic activity has slowed, resulting in greater geological stability.
• Historical earthquakes suggest occasional mild tremors due to remaining faults.

Earthquake Sounds

• Peculiar sounds during earthquakes can be due to low-frequency vibrations beyond human hearing.
• Different sounds might be perceived due to the vibration of buildings rather than the earthquake itself.

Likelihood of Large Earthquakes

• History records significant past earthquakes in Delhi, such as those in 1720 and 1803, but these originated elsewhere.
• Current tectonic conditions in Delhi suggest the unlikelihood of a large earthquake occurring.
• Dense population and infrastructure make the potential impact of large earthquakes significant, though the probability remains low.