若羌6．6级地震形变前兆异常的对比观测研究

CONTRASTIVE OBSERVATION UPON PRECURSORY DEFORMATION ANOMALIES OF THE RUOJIANG EARTHQUAKE OF 6.6

研究了１９９３年若羌６．６级地震前库尔勒地震台多种形变（应力、应变）对比观测资料，结果表明，前期异常始于１９９０年底，主体异常始于１９９３年２月，震前２─４个月是异常发展的高潮期。各手段观测到的异常彼此呼应，相互印证；起始和转折变化时间，或同步一致，或相继跟随；它们的异常幅度（量级）相差较大，在１０－６─１０－４之间；异常形态各有特点，而又不无相似。朝向震中的应变观测元件异常最明显，而倾斜矢量异常方向都背向震中。

Various Contrastive deformation observations before the Ruojiang earthquake of 6.6 at the Kuerle seismic station are investigated. The results show that The preceding anomaiies began at the end of 1990 and the principal anomalies in February, 1993. The period of 2～4 months before the event was the anomaly peak. The anomalies obseved with various means echo and corroborate each other, their begining and turning moments syehronize or close follow each other. The amplitude of anomalies made considerable difference of 10-4～10-6, their patterns have respective speciality but are similar to each other in some wary. The elements of strain observation towand the epicenter displaid very clear anomaly while the directions of anomal tilt rectors all were beckward. Finally, this paper discusses anomaly stage dividing, complexity of precusory anomalies and the posibility of observing inevitable earthquake informarion.