4.9-magnitude earthquake hits Uttarakhand:Tremors also felt in Delhi-NCR, Himachal Pradesh, Punjab, Haryana; no casualties reported

Earthquake struck Uttarakhand at 10:30 pm on Tuesday, prompting people to step outside their homes. Tremors felt across several parts of northern India, including Delhi-NCR, Himachal Pradesh, Punjab and Haryana. The region lies in high seismic zone and is prone to tremors. The earthquake was initially reported as measuring 4.4 magnitude, but the latest data from the National Centre for Seismology put its magnitude at 4.9. A 4.9-magnitude earthquake is generally classified as a light earthquake and there were no reports of casualties or damage following the strike. Earlier in the day, a 4.5-magnitude earthquake struck Assam’s Nagaon at around 4.30 am, according to the seismological department. Why do earthquakes occur? The surface of our earth is mainly made up of 7 large and many small tectonic plates. These plates keep floating continuously and sometimes collide with each other. Due to collision, the corners of the plates often bend and when there is more pressure, these plates start breaking. In such a situation, the energy coming out from below finds a way to come out and after this disturbance an earthquake occurs. What is a shallow-depth earthquake? This earthquake in Delhi was a shallow-depth earthquake, with its origin located about 5 km deep. Shallow earthquakes tend to cause more noticeable shaking and are felt strongly near the epicentre. A shallow-depth earthquake occurs when the quake’s origin is near the Earth’s surface (less than 70 km deep). Shallow quakes generally feel stronger because the energy has less distance to travel before reaching the surface. Shallow quakes can cause more intense shaking and damage, especially in densely populated areas. What caused a boom-like sound during the earthquake? When the earthquake’s waves move through the ground, they can create vibrations that are loud enough to hear as a boom-like sound. The shaking can also cause pressure changes in the air and stress on buildings, making the sound louder. These vibrations move through the air, interacting with structures, and create a rumbling or booming noise during the quake. ​