Nepal has a history of huge seismic activities owing to its geological and geographical vulnerability. This Himalayan region has always been prone to frequent earthquakes.
The January 15, 1934 earthquake had destroyed several places in Nepal, Bihar and West Bengal. Over 30,000 people were killed in the disaster. This quake is considered to be one of the worst quakes in Indian history. The epicenter of the earthquake was in eastern Nepal.
Why is Nepal prone to severe earthquakes?
The remnants of a prehistoric lake, a 300 meter-deep layer of black clay, lies underneath the Kathmandu Valley. According to a study by the Netherlands-based International Institute for Geo-information Science and Earth Observation, this augments the damage caused by severe earthquakes. Therefore, the region is susceptible to soil liquefaction. During strong quakes the solid ground turns into something like quicksand, swallowing everything above the ground.
Also read What is an earthquake?
What caused the recent Nepal Earthquake?
The 7.9 magnitude earthquake that hit Nepal on Saturday was the result of an ongoing collision of tectonic plates, which has caused deadliest earthquakes in the past including the Kashmir quake in 2005.
The Indus-Yarlung suture zone, lying in the southern border of Nepal, collided with the Eurasian plate some 40 million to 50 million years ago. Today, the Indian subcontinent lies on the Indus-Yarlung suture zone and the Eurasian plate includes most of Europe and Asia. This collision created the Himalayan mountain range.
When the India plate pushes its way towards Asia, immense pressure builds up at the point where the two landmasses meet. Consequently, one landmass slides above the other giving rise to a shock-wave called an earthquake.
Why was the Nepal earthquake so dangerous?
Magnitude is not the only measure of an earthquake’s potential for destruction, depth at which occurs is equally important. The closer the epicentre of the quake, larger is the impact above the ground. The location of the occurrence of a quake also matters.
Several factors worked together to make Saturday’s earthquake in Nepal such a devastating event. First of all, it recorded 7.8 on the Richter scale and was reported to be one of the most powerful earthquakes to strike the region in the past 80 years. Secondly, it was shallow as it occurred just about 10 km below the ground.
Image credit - Omar Havana
