摘要
从大量的地震参数分析可知,在由同一主震引发的所有的余震发生的位置都不同。在发生地震之前,地震的震中位置都是一些相互独立、互不连续且发生了弹性应变的单元个体,笔者称这些独立不连续的弹性应变单元称为应变量子。综合前人研究成果,笔者建立了一个地震模型。运用该模型对2008年5月12日发生在中国汶川地震作了解释:由于在龙门山断裂带周围形成了许多的应变量子,这些应变量子的形成阻碍了龙门山断裂的运动,产生滑移亏损,从而造成在地震前测量到的龙门山断裂带速度场变化很不显著。2008年5月12日14时28分时,在龙门山断裂周围已形成应变量子中的其中一应变量子最先达到它的最大储能,释放它所储存的应变能,引发了汶川Ms8.0地震。此次地震产生的地震波引发了龙门山断裂周围地壳应力的重分布,使得其他应变量子提前达到最大储能,释放出能量,于是触发成千上万次余震。此外,我们或许可以通过观测断裂滑移速率的变化情况来预测断裂周围应变量子的形成,从而来预测该断裂是否存在潜在地震的可能。
Aftershocks triggered by an earthquake were located at different positions as shown by a large number of seismic parameters.Before the earthquake these positions can be looked as some units that are independent,discontinuous each other,and under elastic deformation.The author named them strain quanta.In combination with previous research findings,the author set up an earthquake model,and the Wenchuan earthquake in China that took place on May 12th,2008 is interpreted with the model as follows： The strain quanta,which were formed in Longmenshan fault zone,hindered the movements of Longmenshan fault,and then brought about slip deficit.That made the velocity-field change in Longmenshan fault zone measured before the earthquake very unconspicuous.At 14：28 on May 12,2008,one of the strain quanta reached its maximum energy storage in the first place,so it released its energy and made the surrounding crustal stress redistributed.The stress redistribution reduced the maximum energy storage of other strain quanta and made them release their energy in advance,and then caused the Ms 8.0 earthquake and subsequently many aftershocks.Moreover,we can make use of the observation of the velocity field change among the faults in the same plate to predict earthquakes.The smallest change of speed field of the fault will be measured out if many elastic strain quanta are formed along it;the elastic strain quanta are the source of the future earthquakes;and the fault is the potential earthquake fault.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2010年第5期142-150,共9页
Earth Science Frontiers
基金
中国石油化工股份有限公司重点研究项目"中国西北地区构造-岩相古地理研究与编图"(07370502000130)
关键词
地震
中国汶川
滑移亏损
龙门山断裂
应变量子
earthquake
Wenchuan of China
slip deficit
Longmenshan fault
strain quanta
