结合异年倍九律鉴别前震类型
Use of Rhythm of Nine Multiplied Days in Different Years to Identify Type of Foreshock

鉴别前震的方法甚多。该文主要运用异年倍九法（或称异年倍九律）帮助鉴别前震。鉴别的方式是在欲鉴别的小震或小震群发生地区寻找组成异年倍九律的地震，其某个第九天日期若与该小震或小震群发生日期相重或相近，则认为这个小震或小震群可能是前震。文中列举了2010年玉树大震前的小震和2008年汶川大震前都江堰小震群的实例，皆被鉴别为可能是前震。
Many methods have been developed to distinguish earthquake foreshock. In this study, we used the rhythm of nine multiplied days in different years to distinguish foreshocks. In this method, we look for earthquakes that conform to the rhythm of nine multiplied days in different years in regions where a small earthquake or earthquake swarm occurred. If one day among the nine in different years occurred close to the day the small earthquake or earthquake swarm occurred, we consider that this small earthquake or earthquake swarm may have been a foreshock. Two examples were identified:the small earthquake before the Yushu MS7.1 earthquake in 2010 and the small earthquake swarm before the Wenchuan MS8.0 earthquake in 2008, both of which could possibly have been foreshocks