After a lull of nearly two decades the earth rumbled in the Uttarakhand region of the high Himalayas with a moderate 5.6 magnitude earthquake on Monday night.
Sequentially, a 6.8 magnitude earthquake rocked Uttarkasi in October 1991. It was followed by a similar intensity quake that hit Chamoli in March 1999. Now after a gap of 18 years, an earthquake with its epicentre at Gupth Kashi in Rudraprayag district of Uttarakhand has occurred.
Described by earthquake experts as a `tectonic episode', the latest quake has so far reportedly not caused any significant damage, but for reports of people feeling the shake across the North, including the national Capital Delhi.
The Himalayan region is seismically active and the possibility of a major earthquake is always present. However, the activity witnessed in the Uttarakhand region is essentially a release of latent strains in the earth's interiors.
"In the past few hundred years there has been no major earthquake and there is a build-up of stresses, which makes it a highly stressed location. Moderate intensity quakes are a way of release this energy", said Srinagesh, a senior Seismologist with the National Geophysical Research Institute (NGRI), Hyderabad.
In contrast, major earthquakes have occurred in other parts of the Himalayan region. For example, the massive Kangra (Himachal Pradesh) earthquake of 1905 and the two big ones that wrecked havoc in Nepal -- 1934 and 2015.
The NGRI has three seismic observatory stations in Almora and Rudraprayag districts. Reports from there state that the ground shook but caused little or no damage. The depth of the earthquake recorded at 10.33 pm was 14 km, he told BusinessLine .
In scientific parlance the explanation for the earthquake is the result of the collision between the Indian-Eurasian plates. The region is called the diffused seismic zone where vulnerability is high.