Earthquake in Nepal, tremors in Delhi: What it means to be in seismic zone 4

As a 6.3 Richter earthquake struck Nepal early on Wednesday, the tremors and aftershocks were felt in the Delhi-NCR. North India, being in the seismic zone 4, has to prepare for such shocks. Here's what the preparations involve when a region is in zone 4.

Many residents of Delhi-NCR woke up abruptly early Wednesday morning as tremors from an earthquake in Nepal struck the NCR region. The earthquake was logged at 6.3 on the Richter Scale on 1.57 am on Wednesday, according to the National Center for Seismology.

AFTERSHOCKS CONTINUED FOR SEVERAL MINUTES

"Earthquake of Magnitude:6.3, Occurred on 09-11-2022, 01:57:24 IST, Lat: 29.24 & Long: 81.06, Depth: 10 Km, Location: Nepal," National Center for Seismology tweeted soon after the earthquake.

According to the NCS, the epicentre was located about 90 km east-southeast of Pithoragarh in Nepal. Soon after the initial shocks, the National Earthquake Monitoring Centre of Nepal recorded a 6.6-magnitude quake at 2.12 am, with its epicentre in the Doti district. Mild aftershocks of these earthquakes were also felt in the Uttarakhand-Nepal region at 3.15 am (3.6 Richter) and 6.27 am (4.3 Richter).

DELHI-NOIDA BUILDINGS SHOCK RESISTANT

In Noida's high-rise societies, people felt the tremors and rushed onto the streets. There were no casualties or massive structural damage reported in northern India due to the strong earthquake. Experts said the construction quality prevented any major damage due to the tremors.

According to structural engineers, the technology available at present has been developed over the years to withstand major shocks during events, such as earthquakes. Such technology is required because most of northern India and parts of the Himalayan range are categorised under seismic zone 4.

REGION PRONE TO EARTHQUAKES

The Himalayan belt is the seismically most active belt. Earthquakes occur in this region when two continent plates — Indian and Eurasian —collide. The earthquake in April 2015 was logged at 7.8 on the Richter scale near Kathmandu, which devastated Nepal.

It seems the quake that hit Delhi on Wednesday was 5.7 Richter — the biggest in Delhi in 60 years. The last strong earthquake — 5.7 Richter — was recorded in July 1960.

Delhi is prone to earthquakes because it is located in the fourth-highest seismic zone out of the five.

However, Delhi has seldom been the epicentre of an earthquake. It, however, experiences tremors when an earthquake occurs in high-seismic areas like central Asia or the Himalayan ranges.