Society
Scientists search for signs of an earthquake
By Peng Yining (China Daily)
Updated: 2010-01-28 07:07
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On the morning of Feb 4, 1975, residents in Haicheng were evacuated from their homes because local officials feared a large earthquake was about to strike. They were right. Nine hours later, the city in Liaoning province was rocked by a 7.3-magnitude tremor.
Scientists in the city, which has a population of 1 million, said they raised the alarm after recording a 3.1-magnitude tremor and 1,000 smaller aftershocks the previous day.
The incident is regarded as the world's first successful earthquake prediction. But was it a prediction or simply coincidence?
"The prediction of earthquakes is a problem for scientists all over the world," said Chen Xuezhong, a researcher at the institute of geophysics under the China Earthquake Administration, who said that many contributing factors to earthquakes were still a mystery. "Without knowing the cause of a disease, a doctor can't give the right treatment."
Those people who claim earthquakes can be precisely predicted rarely use a scientific approach, he said.
Referring to the events in Haicheng, he said: "Over 1,000 slight earthquakes provided scientists then with an obvious indication, but that is rare. Some indicators, such as the abnormal behavior of animals or slight tremors, usually are not connected with disasters."
People should be encouraged to report any signs of potential earthquakes to the authorities, no matter how small, said Sun Shihong, a retired researcher for the China Earthquake Administration.
"Animals usually give us signs, and people should be alert if they see snakes wake up early from their winter hibernation, or if rats seem to be fleeing a basement, or even if dogs bark madly. Changes in the taste, color and levels of well water should also be noticed," he said. "People should know what the indicators of earthquakes are and how to protect themselves from being hurt in possible disasters."
China has been working on a prediction system since the 1960s and Sun said he believes the authorities will one day be able to successfully predict every earthquake.
"Earthquake prediction is far more difficult and complicated than a weather report," he said. "The government can't evacuate people for every mad bark or slight tremor. Most of the time, the prediction just gives people a warning about the disaster."
Researcher Chen agreed and added: "When we are equipped with more advanced technology we can recognize the natural phenomenon."
With such a large population, every powerful earthquake has the potential to cause a huge loss of life, and a prediction mechanism is vital for China to avoid the kind of tragedy seen in Sichuan in 2008, which left more than 87,000 people dead or missing.
"But any successful prediction system is a long way off," said Chen.
(China Daily 01/28/2010 page7)
