Though scientists had warned of the high probability of a massive earthquake in Nepal, the devastation caused by the 7.9-magnitude temblor was greater because of unplanned urbanisation and the failure of authorities to put in place measures to mitigate the damage.
Saturday’s earthquake killed more than 2,200 and left tens of thousands more without shelter. Many people were killed or injured when shoddily constructed buildings collapsed in congested cities such as the capital Kathmandu.
A report published earlier this month by GeoHazards International, a US-based nonprofit that helps poor nations in tackling disasters, had warned that Kathmandu ran the risk of massive destruction whenever a calamity struck because of its annual population growth rate of 6.5% and one of the highest urban densities in the world.
“It was also clear that the next large earthquake to strike near the (Kathmandu) Valley would cause significantly greater loss of life, structural damage, and economic hardship than past earthquakes had inflicted,” the report said.
The report further said the Nepal government did not control the valley’s rapid development and there were no building codes in place. “…nearly all construction took place without consideration of seismic force concerns,” it said.
A group of 50 earthquake experts had visited Kathmandu a week earlier to discuss how to prepare the city for a “big one” like the 8.1-magnitude quake of 1934 that killed 19,000 people in Nepal and Bihar.
"Physically and geologically what happened is exactly what we thought would happen," said seismologist James Jackson, head of the earth sciences department at the University of Cambridge, who was a part of that group.
"I was walking through that very area where that earthquake was and I thought at the very time that the area was heading for trouble," he said.
A report from the US Geological Survey explaining Saturday’s earthquake said the primary reason for the temblor was the forces acting between the India and Eurasia tectonic plates. It hinted at the inevitability of the quake because the Himalayan region witnesses a huge degree of seismicity.
According to the plate tectonics theory, the earth's outer shell is divided into several plates that glide over the rocky layer above the core.
“Northward under-thrusting of India beneath Eurasia generates numerous earthquakes and consequently makes this area one of the most seismically hazardous regions on Earth,” said the USGS report.
This interplay of forces began more than 25 million years after these plates crashed into each other.
“The India and the Eurasia plates constantly brush against each other and situations often arise when minor tremors are created. But sometimes this brushing lead to massive quakes,” Anirban Chakraborty, a research scholar at the Disaster Prevention and Research Institute, Kyoto University, Japan.
Chakraborty questioned Kathmandu’s urban development plans and said a quake of the same intensity would kill fewer people in a sparsely developed area than in a congested area like the Kathmandu Valley.