Tragic lessons of India's quake

Cracks up to a metre wide appeared in the ground

By BBC News Online's Ivan Noble

Many lives could have been saved in the Gujarat earthquake if building codes had been enforced and cheap protection measures carried out, Indian scientists say.

A new study concludes that much of the damage to relatively new multi-storey buildings happened because regulations for building in high earthquake-risk areas were ignored.

Non-adherence to the high-risk zone building codes is chiefly responsible for the damage to many recently constructed multi-storied buildings

Indian National Geophysical Research Institute team

Building codes must be strictly enforced and existing buildings strengthened to prepare the country for any future quakes, say experts at the National Geophysical Research Institute, Hyderabad.

At least 30,000 people were killed when the earthquake struck the Kutch region of Gujarat in western India on the morning of 26 January.

Metre-wide cracks

The research by Harsh Gupta and colleagues, published in the journal Science, reveals that cracks up to a metre (three feet) wide appeared in the ground close to the epicentre of the quake. Buildings not engineered to withstand earthquakes collapsed entirely.

Dr Gopal Madabhushi of the University of Cambridge, UK, says that when he visited the area with a British team after the quake, he drew similar conclusions:

When the earthquake starts, the mortar cracks and they just turn into a pile of rubble

Dr Gopal Madabhushi
Cambridge University

"Indian building codes, even though they are old, do have some earthquake resistance measures.

"But on the ground we found no implementation at all. Even the basic things had not been done correctly," he told BBC News Online.

'Pile of rubble'

Buildings in Bhuj, close to the epicentre, are usually built from local sandstone and covered with a clay mixture called adobe.

Some use regular sandstone blocks, but the cheapest buildings use irregular blocks held together with mortar.

"We found that the regular blocks offered quite good earthquake protection but with the irregular blocks, when the earthquake starts, the mortar cracks and they just turn into a pile of rubble," Dr Madabhushi explained.

Encouraging local builders to use regular blocks would save lives in any future quake, he said.

History of destruction

January's earthquake in Gujarat was unusual in that it took place in the middle of a tectonic plate.

Earthquakes usually happen at the edges of tectonic plates when tension caused by them rubbing together is released.

But the Bhuj earthquake was by no means the first in the region.

The Hyderabad team detail a series of serious quakes in the area in centuries past:

• In 1668, all 30,000 houses in the town of Samaji on the Indus delta reportedly sank into the ground.
• In 1819, 2,000 people were killed in Ahmedabad and Kutch and a 90 km (56 mile) long scarp up to nine metres (30 feet) high was formed.
• In 1956, 115 people were killed in a magnitude seven quake in Anjar.