氮氦比对地震的反映

REFLECTION OF N2/He RATIO ON EARTHQUAKES

聊古_1井位于聊考断裂带的北段。自1981年以来对该井水中的氮气和氦气每日进行定量观测。通过对聊古_1井的氮氦比在1981年11月9日宁晋M_s5.8级地震(Δ=150km)和1983年11月7日菏泽M_s5.9级地震(Δ=140km)震前变化的分析,发现N_2/He在这两次地震前2个月左右的时间均出现明显的高值异常,且均在异常转折、恢复的过程中发震。由此N_2/He在震前的变化可能作为一项短期前兆异常预报指标。 然而,从该井的氮气和氦气的单独观测曲线及一般的处理方法处理后的曲线看不出明显的异常。采用氮气和氦气两者的比值后,则可以看出异常,这是由于两者的比值可以消除某些干扰因素的影响,例如:温度、湿度、气压及取样化验等。

A Liaogu well is located at the northern segment of Liaokao fault zone. Since 1981, the N2 and He gases in the well water are quantitatively observed every day. Through analysis of the N2/He ratio changes in this well before Ningjin Ms5.8 earthquake on Nov. 9, 1981, △ = 150 km and Heze M5.9 earthquake on Nov. 7, 1983 (△ = 140 km), it is found that about 2 months before the two events N2/He had obviously high anomaly value, and earthquakes occurred in the turning and recovery process, thus, the variation of N2/He before earthquakes might be regarded as a predicting index for short-term precursory anomaly. However, no obvious anomalies of single observation curve of N2 and He gases in this well and the curve processed by general processing method can be found. After adopting N2/He ratio, the anomaly can be found; the reason is that the ratio can remove interferences of some disturbed factors, such as temperature, humidity, air pressure as well as error of sampling and chemical .analysis.