A powerful earthquake measuring 4.0 on the Richter scale struck Delhi this morning and the quake was experienced in several neighbouring areas of the national capital.
The quake occurred at a depth of approximately 5 km, as per the National Centre of Seismology. Though there have been no reports of casualties or injuries, people heard a loud noise for a few seconds when the earthquake struck Delhi.
The grumbling noises produced at the time of the tremors are normally seen in a shallow-focus earthquake. The US Geological Survey (USGS) states that high-frequency ground vibration from shallow earthquakes creates a booming noise as the ground shakes and develops a short-period seismic wave motion that travels to the air and is converted into sound waves.
The lower the epicentre, the more energy and noise can be generated. At times, earthquakes are capable of producing booming noises without any vibrations being experienced.
Delhi is situated in the Seismic Zone IV with relatively high seismicity, as stated by the Delhi Disaster Management Authority. Earthquakes tend to occur in the range of 5-6 magnitude in the zone, and even 7-8 sometimes. Zoning is a progressive procedure that constantly changes.
The North Indian seismicity, including that of the Himalayas, results from the Eurasian plate being collided with the Indian plate. The colliding plates bend and accumulate energy in the way a spring stores energy, and when the plate margin eventually breaks to release this energy, the result is an earthquake.
