World

Nepal earthquake: Shallow quakes pack more punch

Shallow earthquakes carry more destructive power, and Saturday's quake in Nepal was the largest of its kind since the 8.2 temblor off the coast of Chile in 2014.

Tremors brought down centuries-old temples and towers in Kathmandu

Volunteers work to remove debris at the historic Dharahara tower, a city landmark, in the wake of a 7.8-magnitude earthquake in Kathmandu, Nepal. (Niranjan Shrestha/Associated Press)

The U.S. Geological Survey put the magnitude of Saturday's quake in Nepal at 7.8. It said the quake hit at 11:56 a.m. local time at Lamjung, about 80 kilometres northwest of Kathmandu. Its depth was only 15 kilometres, the largest shallow quake since the 8.2 temblor off the coast of Chile on April 1, 2014.

Quakes that are closer to the surface carry more destructive power, and witnesses said the trembling and swaying of the earth went on for several minutes.

A magnitude 7 quake is capable of widespread and heavy damage while an 8 magnitude quake can cause tremendous damage. This means Saturday's quake — with the same magnitude as the one that hit San Francisco in 1906 — was about 16 times more powerful than the 7.0 quake that devastated Haiti in 2010.

"The shallowness of the source made the ground-shaking at the surface worse than it would have been for a deeper earthquake," said David A. Rothery, professor of planetary geosciences at the Open University in Milton Keynes, north of London.

All the houses around me have tumbled down.- Witness Jenny Adhikari

A major factor in the damage was that the buildings were not built to be quake-proof. An earthquake this size in Tokyo or Los Angeles, which have building codes for quake resistance, would not be nearly as devastating.

The power of the tremors brought down several buildings in the center of the capital, the ancient Old Kathmandu, including centuries-old temples and towers.

Among them was the nine-storey Dharahara Tower, one of Kathmandu's landmarks built by Nepal's royal rulers as a watchtower in the 1800s and a UNESCO-recognized historical monument. It was reduced to rubble and there were reports of people trapped underneath.

Hundreds of people buy tickets on weekends to go up to the viewing platform on the eighth story, but it was not clear how many were up there when the tower collapsed. Video footage showed people digging through the rubble of the tower, looking for survivors.

The quake shook Nepal's capital and the densely populated Kathmandu Valley before noon Saturday, causing extensive damage with toppled walls and collapsed buildings, officials said. (Niranjan Shrestha/Associated Press)

Buildings poorly constructed

The Kathmandu Valley is densely populated with nearly 2.5 million people, and the quality of buildings is often poor.

In Kathmandu, dozens of people gathered in the parking lot of Norvic International Hospital, where thin mattresses were spread on the ground for patients rushed outside, some wearing hospital pajamas. A woman with a bandage on her head sat in a set of chairs pulled from the hospital waiting room.

Doctors and nurses hooked up some patients to intravenous drips in the parking lot, or were giving people oxygen.

A Swedish woman, Jenny Adhikari, who lives in Nepal, told the Swedish newspaper Aftonbladet that she was riding a bus in the town of Melamchi when the earth began to move.

"A huge stone crashed only about 20 metres from the bus," she was quoted as saying. "All the houses around me have tumbled down. I think there are lot of people who have died," she told the newspaper by telephone. Melamchi is about 45 kilometres northeast of Kathmandu.

Nepal suffered its worst recorded earthquake in 1934, which measured 8.0 and all but destroyed the cities of Kathmandu, Bhaktapur and Patan.

The sustained quake also was felt in India's capital of New Delhi and several other Indian cities.

India's Prime Minister Narendra Modi called a meeting of top government officials to review the damage and disaster preparedness in parts of India that felt strong tremors. The Indian states of Uttar Pradesh, Bihar and Sikkim, which share a border with Nepal, have reported building damage. There have also been reports of damage in the northeastern state of Assam.

Pakistan Prime Minister Nawaz Sharif offered "all possible help" that Nepal may need.

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