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Seismologist Tells Regret, Expectation of Quake Prediction

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Sun Shihong was driving toward Kunming in southwest China's Yunnan Province when his handset beeped. It was about 2:34 PM on May 12, 2008.

The text message from a monitoring station in Qinghai Province said a 7.8-magnitude earthquake had just taken place in Sichuan, neighboring province of Yunnan. The epicenter, marked by longitude and latitude, was later identified as Wenchuan County.

A senior earthquake expert with the Beijing-based China Earthquake Administration (CEA), Sun had come to Yunnan a couple days earlier on a field assignment. "I was surprised, but not entirely," Sun recalled in an interview with Xinhua.

Sun was one of the nine chief predictors at CEA's China Earthquake Networks Center (CENC). He specialized in quake prediction based on data analysis. In 2006 he forecasted that there would be a strong earthquake within two or three years somewhere in southwest China.

"I was surprised it occurred in Wenchuan," Sun said with regret. Hardly a month before, he had been in Sichuan on a different research trip not far from Wenchuan.

"We failed to include that part of Sichuan in the danger zone, because there were few significant tremors or abnormal signs associated with the Wenchuan area," Sun said, "Looking back now, a year later, I still say it was impossible for us to make the prediction. We've done our job."

Hurrying back to Beijing on the earliest available flight, Sun landed at the airport well past midnight. He took a few hours of sleepless rest at home before going to the office. He then spent days dealing with the media.

Unlike many of his colleagues, Sun did not fly to Wenchuan shortly after the quake. In addition to dealing with the media, he was on a special mission to ensure the safety of the Beijing Olympic Games. He did not have a single day off till the Games was over. He retired in October but has remained closely involved in earthquake affairs.

He participated in the revision of the Law on Protecting Against and Mitigating Earthquake Disasters. He was entrusted to take charge of the third chapter, which covers monitoring and prediction. The work of revising the legislation actually started in July 2007. The Wenchuan earthquake quickened its pace. The new law became effective on May 1.

Not everyone was happy with the new law, though. Opinions were divided over the use of "prediction," which means releasing or publicizing a quake forecast, Sun said. People who wanted to delete the word said that current earthquake science was incapable of making accurate forecasts.

The longstanding dispute over prediction was rekindled by the failure in Wenchuan. Proponents argued that prediction was needed because of the country's unique conditions. China was quake-prone and protective measures against it, especially construction, were far from adequate.

Predictions, therefore, were seen as the best option. It has been done, for example, in February 1975, when a 7.3 magnitude quake occurred in north China's Haicheng.

But even many supporters of predictions said that making very accurate forecasts, which were the meaningful predictions for the general public, was almost impossible at present. It might take centuries to achieve such accuracy. "But efforts should not stop, even if only in preparation for the future," Sun said.

Many of the older generation of Chinese seismologists seemed to share Sun's faith in the future of quake prediction. They felt a strong sense of social responsibility.

The new law reiterated that only high-level earthquake administrations were authorized to make predictions. Concerned over construction quality, people in China took quake predictions seriously.

Rumors could be very damaging economically and politically, in terms of social stability.

Strict government control of quake prediction denied any non-official researcher the right of making predictions. But quake forecasts by such researchers might be examined and, at least in theory, disseminated by the government if they were convincing. The mechanism, in practice for decades, was confirmed in the new law as "mass monitoring and preparation".

Sun had been responsible for classifying and scrutinizing quake reports and forecasts. He didn't remember receiving anything that forecasted the Wenchuan earthquake. "An unlikely-sounding forecast from an experienced observer might get fairly close to reality, but we won't usually buy such claims. We'll check a forecaster's records. If he doesn't have a sound record of successful forecasts, how can we believe him?" Sun said.

Supporters thus won a victory in the legislation, which meant quake prediction could legally continue.

But the new law, reflecting the lessons of previous disasters, gave more importance to other protective measures such as higher quality of construction, public education on surviving quakes, and rescue training. Protection against earthquakes was seen as a multi-faceted effort that should involve quake monitoring, prediction, injury and damage prevention, disaster rescue and relief, and post-quake reconstruction.

"China's quake legislation is delivering. Research should catch up," CENC deputy director Zhang Xiaodong said in an interview.

According to Zhang, there was progress last year in enhancing the performance of quake monitoring and rapid report networks. As a result, initial reports became faster and more informative.

Seismic administrations in most provinces were now expected to submit reports of 3.5 magnitude or stronger quakes in less than 20 minutes, five minutes faster than before. To facilitate rescue and relief operations, the report must include information about the population density and distribution, as well as quake records of the epicenter and affected areas.

Prediction remains an important method to guard against quakes, especially for periods of months or years, something that modern technology was capable of delivering.

Although the general public might not find such predictions useful, a long-term outlook could be used to secure the safety of reservoirs, oil fields, nuclear power stations and the like.

And while it seems impossible now, Chinese seismologists are pursuing short-term quake predictions. "It's the ultimate goal of CEA and the very reason the institution was started in 1971," Sun said.

The Wenchuan quake was a severe blow to the morale of seismologists, the younger generation in particular. But Sun, 61, who was probably the last of the old generation to retire, said he did not regret devoting the best part of his life to this profession. "I'm not sure if designing a missile is really in the interests of mankind. But the job of earthquake prediction clearly is, " he said with a smile.

(Xinhua News Agency May 12, 2009)

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