Teng Jiwen, a famous Chinese geophysicist and an academician of the Chinese Academy of Sciences, gave a lecture recently to the public in central China's Henan province, in which he told the audience that earthquake prediction remains one of the most difficult goals to achieve in present-day world. Teng said that the distance between the surface of the earth and its core is approximately 2,600 kilometers while the deepest point that humans can reach even with the most advanced drilling rig is only 12.2 kilometers into the crust, the outer layer of the earth. The high solution instruments can merely survey the structures of earth's crust. In addition, because of the varied geological structures in different areas, the types and causes of earthquakes are not totally the same. Therefore, we have not so far found any reliable patterns that would lead to our deeper understanding of earthquake precursors and successful prediction of earthquakes. Teng Jiwen stressed that the important thing is to foster an awareness of prevention and take effective measures to prevent and explore the practical ways of mitigating to the utmost extent disaster caused by earthquake. Teng gave examples in which difference in preparedness against a possible earthquake resulted in completely different outcomes when the earthquake did occur. The 7.8 magnitude Tangshan earthquake in 1976, which led to the death of 248,000 people, took 10 years to make a recovery from the disaster, while the 2010 earthquake in Chile of the same magnitude (7.8) caused the death of 177 people and took 10 weeks to make a recovery.
Another example is Liuhan Primary School in Beichuan county, which is at the epicenter of the 2008 Sichuan earthquake, The building of that school suffered little damage and there was no causalities during the disastrous quake thanks to its schoolmaster's persistent effort to arrange teaching of earthquake emergency knowledge and repeated drills for the teachers and children, as well as the careful reinforcement of school buildings. On the contrary, Yingxiu Primary School, next to it, was completely ruined. "It's a lesson at the cost of blood and life that we should all keep in mind."
|
