Early warning: A map of the 12 May quake zone showing the epicentre in Sichuan, China.

Credit: Wikipedia

Related articles

• New: earthquakes you can't feel
• Quakes can be triggered from Earth's flipside
• Monster quake forecast for California
• Indonesia to install tsunami sirens on mobile phone towers
• The science of the Peru quake

BEIJING: Scientists in China are calling for improvements in earthquake prediction, including the establishment of an early-warning system and methods to share quake information.

The calls come after the 12 May Sichuan earthquake, which was the most serious to strike the country in three decades.

Ni Sidao, a professor of geophysics at the University of Science and Technology of China, said that although current scientific methods cannot accurately predict an earthquake, an early-warning system could alert people to leave for open spaces before buildings are destroyed.

Warning window

Ni made his remarks at the China Science and Humanities Forum in Beijing, operated by the Graduate University of the Chinese Academy of Sciences.

He said that P waves – which are early, less destructive seismic waves – could be used to detect and calculate the scale of an earthquake within ten seconds with the aid of computers.

In the case of Sichuan, later, more destructive seismic waves (S waves) took 30 seconds to reach the most severely hit region (Beichuan 90 km north of the epicentre) and nearly 100 seconds to reach Qingchuan County, 200 km from the epicentre.

People in Beichuan could have had at least a ten-second warning of the earthquake with an early warning system, which might have allowed some people to move outdoors and allowed trains to stop to prevent derailing, said Ni.

But he admitted that current seismic monitoring stations in most parts of China are too isolated to form a warning network.

Ren Luchuan, a senior researcher at China Earthquake Networks Centre (CENC), welcomes Ni's suggestions, but said that such a system would be very difficult to operate.

"[The time difference between P and S waves] is so short that it's very hard to establish a system to notify residents," he said. However, such a system could be used for key sites such as nuclear power stations, which could close reactors, he added.

Longer-term prediction seems to be just as fraught with problems.