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地震 ›› 1998, Vol. 18 ›› Issue (2): 141-145.

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大震前地下流体的远场中期前兆异常

张朝明, 丁守英, 余华扬, 张军   

  1. 中国合肥 230031 安徽省地震局
  • 收稿日期:1997-04-14 修回日期:1997-07-20 出版日期:1998-04-30 发布日期:2022-05-10
  • 作者简介:张朝明,男,1945年5月出生,高级工程师, 主要从事地震流体的监测方法、技术及其地震前兆与机理的研究。
  • 基金资助:
    地震科学联合基金会资助项目(92322)部分成果

FAR-FIELD MEDIUM TERM PRECURSOR OF GROUND FLUID BEFORE LARGE EARTHQUAKES

Zhang Chaoming, Ding Shouying, Yu Huayang, Zhang Jun   

  1. Seismological Bureau of Anhui Province, Hefei 230031, China
  • Received:1997-04-14 Revised:1997-07-20 Online:1998-04-30 Published:2022-05-10

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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(1990年7月16日)前,五河井(Δ=2033 km)水位的M2波的振幅比T和相位差Δθ,均有近17个月的低值异常;庐江井(Δ=1800 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(1994年9月16日)前,五河井(Δ=1121 km)水位M2波T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1986年12月至1997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。

关键词: 大震, 地下流体, 中期前兆, 远场

Abstract: 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 M2 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 anom alous low values for 36 months before the event. Before the Taiwan strait earthquake ( M =7.3, Sept. 16, 1994), the a and DJin 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.

Key words: Large earthquake, Ground fluid, Medium term precursor, Far-field