大震前地下流体的远场中期前兆异常
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摘要
通过研究安徽省五河井水位、沪江井井压和流量的观测资料 ,笔者发现了大震前远场中期异常的证据。菲律宾 8.0级地震 ( 1 990年 7月 1 6日 )前 ,五河井 (Δ =2 0 33km)水位的 M2 波的振幅比α和相位差 Δθ ,均有近 1 7个月的低值异常 ;庐江井 (Δ =1 80 0 km)井压和流量均存在近 36个月的低值异常。台湾海峡 7.3级地震 ( 1 994年 9月 1 6日 )前 ,五河井 (Δ =1 1 2 1 km)水位 M2 波α和 Δθ以及庐江井 (Δ =930 km)井压和流量分别有 35～ 36个月低值异常。地震发生时 ,上述低值异常均出现显著的恢复和回跳、同震异常变化。震后 ,所有异常保持高值和正常年变化。从 1 986年 1 2月至 1 997年 6月 ,二井观测资料仅在二次大震前出现同态、同步、同震的异常变化。事实表明 ,某些强震可能存在远场中期前兆异常
Through studying the observed data of water level, well head pressure and outflow in Wuhe and Lujiang wells, Anhui Province, China, the authors found the precursory evidences of the far field. Before Philippine earthquake (M=8.0, July 16, 1990), the amplitude ratio (a) and phase difference (Δθ) of M 2 wave of water level in Wuhe well (Δ=2033 km) showed anomalous low values for 17 months and the well head pressure and outflow in Lujiang artesian well (Δ=1860 km) showed anomalous low values for 36 months before the event. Before the Taiwan strait earthquake (M=7.3, Sept.16, 1994), the a and DJ in Wuhe well (Δ=1121 km) showed low values for 35～36 months while the well head pressure and outflow in Lujiang well (Δ930 km) showed anomalous low values for 35～36 months. At the occurrence time of the earthquakes, the anomalies returned, rebounded and changed coseismically. After the earthquakes, all anomalies keep in high values and normal annual variation. From December 1986 to June 1997, the isomorphic, synchronous and coseismic anomalous variations of the observed data occurred only before these two strong earthquakes. The evidence may indicate that there are the far field medium long term anomalies for some strong earthquakes.
Through studying the observed data of water level, well head pressure and outflow in Wuhe and Lujiang wells, Anhui Province, China, the authors found the precursory evidences of the far field. Before Philippine earthquake (M=8.0, July 16, 1990), the amplitude ratio (a) and phase difference (Δθ) of M 2 wave of water level in Wuhe well (Δ=2033 km) showed anomalous low values for 17 months and the well head pressure and outflow in Lujiang artesian well (Δ=1860 km) showed anomalous low values for 36 months before the event. Before the Taiwan strait earthquake (M=7.3, Sept.16, 1994), the a and DJ in Wuhe well (Δ=1121 km) showed low values for 35～36 months while the well head pressure and outflow in Lujiang well (Δ930 km) showed anomalous low values for 35～36 months. At the occurrence time of the earthquakes, the anomalies returned, rebounded and changed coseismically. After the earthquakes, all anomalies keep in high values and normal annual variation. From December 1986 to June 1997, the isomorphic, synchronous and coseismic anomalous variations of the observed data occurred only before these two strong earthquakes. The evidence may indicate that there are the far field medium long term anomalies for some strong earthquakes.
引文
1 梅世蓉,冯德益,张国民,等.中国地震预报概论.北京:地震出版社,1993.154～188.
2 万迪,汪成民,李介成,等.地下水动态异常与地震短临预报.北京:地震出版社,1993.164～166.
3 鱼金子,谷圆珠,车用太,等.地下水动态的超远强震异常问题.国际地震动态,1996,(7):8～10.
4 SchwarzschildB.Earthquake yields first real evidence of remote triggering.PhysicsToday,1993,7～19
2 万迪,汪成民,李介成,等.地下水动态异常与地震短临预报.北京:地震出版社,1993.164～166.
3 鱼金子,谷圆珠,车用太,等.地下水动态的超远强震异常问题.国际地震动态,1996,(7):8～10.
4 SchwarzschildB.Earthquake yields first real evidence of remote triggering.PhysicsToday,1993,7～19
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