Series of earthquakes hit Tibet near Nepal border; tremors felt in parts of north India

Chinese media reported that people had been killed in the affected towns, but did not say how many.

According to the US Geological Survey, the 7.1 earthquake, which occurred at 6.35 in the morning, was followed by at least seven aftershocks of magnitude about five. A magnitude difference of one represents a difference of 32 times in the amount of energy released by the earthquake. In other words, a magnitude 7 earthquake is about 1,000 times (32 x 32) more devastating than an earthquake of magnitude 5.

This morning’s earthquakes, including the big one were quite shallow, originating about 10 km below earth’s surface, according to USGS, which means that its potential to cause destruction was very high. In general, the closer to the earth’s surface the origin of the earthquake is, the higher is its destruction potential. That is because earthquakes originating much deeper lose much of their energy by the time they reach the surface. The 2015 Nepal earthquake also originated around 10 km below the surface.

The damage caused by an earthquake is also a factor of how populated the region is. Most of the damage happens near the origin of the earthquake. The tremors can be felt far away depending on how deep below the earth has the quake originated, but these do not lead to much damage. Earthquakes propagate in waves, and they lose energy as they travel. Deeper the origin, the farther they can travel, but the further a place is from the origin, the lesser the chances of destruction.

The location of Tuesday’s earthquakes lies in a region that is susceptible to earthquakes. The entire Himalayan region, from Afghanistan till the end of India’s northeast, is seismically active because of collision between Indian and Eurasian tectonic plates that are pushing against each other. The formation of the Himalayan mountains is also attributed to this same geological activity.