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Seismic Jolt

The deadly Wenchuan earthquake taught China hard lessons about the importance of early warnings and disaster mitigation

Caijing Magazine, Annual Edition 2009

By staff reporter Li Hujun

   Shortly after China’s worst earthquake in decades hit Sichuan Province’s county of Wenchuan, seismologist Li Zhiqiang of the China Earthquake Administration (CEA) predicted the death toll would “quite likely be close to that of the Tangshan earthquake.”

   The Tangshan quake in 1976 killed about 240,000 people and seriously injured another 160,000. But the Wenchuan tremblor was more intense, according to Chinese authorities, measuring 8.0 on the Richter scale and at least 11.0 in intensity at its epicenter.

    The May 12, 2008 Wenchuan disaster claimed about 87,000 lives, ranking it the second deadliest, after the Tangshan tragedy, in the history of modern China.

    Many experts were puzzled and saddened by the failure to predict the 2008 earthquake in Wenchuan, which was followed by a 6.1 magnitude quake August 30 that rocked the city of Panzhihua as well as Huili County in Sichuan Province, and a 6.6 magnitude temblor October 6 in Tibet’s Dangxiong County.

In addition, although Chinese Seismological Networks Center data indicates that the country is experiencing a high period for seismic activity, experts cannot determine how long this period will last, nor predict what 2009 will hold. That means it’s possible that 2009 will be another tense year for professional earthquake watchers and forecasters in China.

In an interview with the official newspaper People’s Daily commemorating the 30th anniversary of the Tangshan earthquake in 2006, CEA Director Chen Jianmin indicated the nation’s seismologists could, to a certain extent, predict earthquakes of certain types in specific regions. He said more than 20 incidents had been successfully predicted in the years after Tangshan, helping avert disasters in 10 percent of all predicted cases.

In the wake of the Wenchuan disaster, Chen acknowledged the fact that China’s failures in earthquake prediction had far outweighed the successes. “We are still in the trial and error stage,” Chen said at the 14th World Conference on Earthquake Engineering (WCEE) on October 13, 2008 in Beijing. The common opinion among scientists currently holds that even a rudimentary ability to accurately predict earthquakes is at least several decades away.

Because China is still undergoing economic transformation, differences in regional economies and a motley mix of old and new buildings highlight the lack of quake-proofing in many areas  a situation that will be difficult to improve in the short term. Therefore China’s future ability to prevent earthquakes and mitigate disasters would partly hinge on its earthquake forecasting abilities.

Research and Models

    Understanding the causes of earthquakes is the first step in accurately predicting temblors. So after the Wenchuan tragedy, the Chinese government increased investment in this area of research.

   An example of the new commitment is the Wenchuan Earthquake Fault Line Scientific Exploratory Drilling Project, which began in November 2008. The project involves a long-term, deep seismic observation system created by drilling two guide holes 1,200 meters into the ground, and two scientific boreholes reaching depths of 3,000 meters.

   Scientists hope the four-year project, a joint effort of the Ministry of Science and Technology along with the Ministry of Land and Resources and CEA, will increase understanding of an earthquake fault line under Wenchuan and provide basic data to aid future predictions, early warnings and monitoring.

   In addition to earthquake predictions, timely reports of quake intensity as well as early warning system are useful tools to mitigate disaster. Certainly, China’s system for rapid monitoring could be improved. Imitating a U.S. Geological Survey (USGS) system, for example, could be a worthy goal.

    “China’s failures in earthquake prediction had far outweighed the successes.”

On the day of the Wenchuan disaster, a USGS mapping report, called ShakeMap, showed the intensity of tremors in quake zone areas just two hours after the temblor hit. These “intensity distribution maps” showed that Wenchuan county was not the only area hit badly and a primary disaster zone with an intensity of 10 stretched from the town of Yingxiu in Wenchuan to Beichuan county.

   However, China’s CEA wasn’t able to release the similar report during the day nor did it disseminate the USGS report. While the ShakeMap is based on preliminary data   and is by no means completely accurate,  the information is invaluable for emergency rescue teams.

    Another trend-setter is Japan’s earthquake early warning system — the world’s first when it was launched in October 2007. The system can raise a red flag before disaster strikes by observing the unique properties of earthquake waves. Longitudinal waves move quickly but have little destructive force, while transverse waves that move slowly are highly destructive. Japanese experts claim many deaths associated with the Wenchuan earthquake could have been prevented if such an early warning system were in place.

    Shortcomings in China’s rapid reporting and early warning systems are well known. CEA’s Chen said at a November 2008 meeting of the China Seismological Networks Center that near-event reports about intensities and disaster conditions should be broadened to provide scientific support to earthquake and disaster relief command centers more quickly and effectively.

   The Chinese government has approved plans to set up a demonstration early warning system in the Beijing and Lanzhou areas. Some provinces and cities are working with CEA as well, underscoring the widespread interest in this potentially lifesaving effort.

Wenchuan Lessons

   To a large extent, these decisions were born from the Wenchuan earthquake. But more is expected. For example, the public still hopes the government will release an objective report about the many schools that collapsed in the Wenchuan disaster. For those that toppled due to poor quality construction, it’s hoped the courts will get involved in a timely manner.

   “After the Wenchuan earthquake, there was an intense debate on the Internet among earthquake engineering experts as to what we had gotten wrong,” said Tsuneo Katayama, president of International Association for Earthquake Engineering, at the opening ceremony of the 14th WCEE.

   “Many agreed that the huge losses of life and property were the result of a number of factors, including insufficient government oversight, construction quality, societal and economic limitations, a lack of awareness, corruption and cultural traditions. Of course, this is an extremely complicated problem, and finding real solutions in any given area is not easy,” he said.

   A proposed amendment to China’s Earthquake Prevention and Disaster Mitigation Law offer a promising answer to the weak links in a system laid bare by the 2008 disasters. In October 2008, during the fifth session of the 11th National People’s Congress Standing Committee, a draft amendment was submitted. A month of public input followed.

   The draft called for improving rules for quake-proof construction and said “schools, hospitals, shopping centers, transport hubs, public cultural facilities and other construction projects involving high concentrations of people should be designed to exceed local quake-proofing requirements for housing construction.” Moreover, for the first time, the proposed amendment calls for bringing quake proofing to rural areas by requiring “research, development and promotion of seismic safety technologies in the countryside.”

Implementing these new rules could pose a challenge, but retooling China’s disaster prevention and mitigation system could be even more difficult.

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