1988年11月6日澜沧—耿马地震的水氡异常

本文研究了1988年11月6日澜沧、耿马7.6和7.2级地震的水氡异常,认为:1.震前中期、短期及临震各阶段异常均有显示;2.中期异常是趋势性上升的高值异常,它占全部异常的比例,与国内其它几次7级地震相比较略偏低;3.短期异常中有高值和低值异常,位于震中区及北西向腾冲-耿马地震带上的水氡观测点,以氡浓度降低的负异常为主要特征;4.震中周围300公里内未发现临震异常,它多出现在300—500公里范围内,特别集中在小江断裂带上。

RADON ANOMALY IN THE NOV. 6, 1988, LANCANG-GENGMA EARTHQUAKE

The radon anomaly in the Nov. 6 , 1988, Lancang-Gengma earthquake (M = 7.6, 7.2) has been studied in this paper. it is suggested (hat. (1) The anomaly appeared in all the intermediate and short-term and impending stages before the event; (2) The intermediate-term anomaly featured a high value with an uprising sense, which shows somewhat lower percentage out of the total anomaly compared with the other M7.0 events in China; (3) The short-term anomaly featured both high and low value. At the radon observation sites that situated in the epicentral area and along the Tengchong-Gengma earthquake belt to the northwest, radon content mainly showed the negative anomaly; (4) The impending anomaly didn't appear within 300 km around the epicenter but occurred in the area of 300-500 km, particularly concentrated along the Xiaojiang fault belt.