托来6.0级地震前波速比异常与中短期预报指标讨论

本文阐述了１９９３年１０月２６日青海托来６．０级地震前河西祁连山中西部的波连比异常并进一步讨论了中短期预报指标。通过托来地震研究得到，波速比低值集中区边缘与低波速比异常值地震条带交汇区可能为未来主震位置，波速比低值在多次中强震后仍然继续异常以及波速比在震前１─６个月显著回升可分别作为较强地震趋势异常和地震发生的短期指标。

ON THE SEISMIC VELOCITY RATIO ANOMALY BEFORE THE TUOLAI Ms6.0 EARTHQUAKE AND MEDIUM-SHORT TERM PREDICTION INDEX

This paper,describes the seismic velocity ratio anomaly of the Tuolai Ms 6.0 earthquakeon October 26,1993,in middle-west section of Qilian Mountain.Hexi area,and discusses the medium-short prediction inedx. Based on the studies of Tuolai earthquake,it is consideredthat the regio0 where the edge of the area concentrating lower value points of seismic velocity ratio intersects the seismic belt with lower velocity ratio anomaly value would be the location of future earthquake.Successively lower value anomaly of the seismic velocity ratio after severalmoderate earthquakes and obvious re-rising of velocity ratio value between 1 and 6 monthsbefore a stronger earthquake are taken as tendency anomaly and a short-term index to predictthe stronger earthquake,respectively.