【摘要】 利用希尔伯特-黄变换方法对2013年芦山MS7.0地震前甘肃省平凉台、四川省成都台和云南省元谋台地电场观测资料进了分析研究。为增强对研究结果的说服力,还对平凉、成都和元谋地电场观测台站在正常时段变化情况,与地震发生前夕的处理结果进行了对比,对成都地电场观测台站在芦山MS7.0和汶川MS8.0地震前的变化情况也进行了对比分析,并得出:1希尔伯特-黄变换方法能够对地电场观测资料进行有效处理,处理结果简单直观;2在芦山地震前1~2个月地电场时频图出现能量增强现象,出现变化的周期范围约为90~1400h,能量最小变化幅度有3个数量级,最大变化幅度达到6个数量级;3通过上述三个地电场观测结果的对比,以及成都地电场观测结果的类比方式,大大提高了分析研究结果的可信度。在讨论部分,对地电场观测中能够观测到震前异常变化的可能性,从实验和数值模拟两个方面进行了相关论述。更多还原

【Abstract】 In this paper,Hilbert-Huang Transformation method is introduced to deal with geo-electric field data observed by the stations around the epicenter of 2013 Lushan MS7.0earthquake.These stations include the stations of Gansu Pingliang,Sichuan Chengdu and Yunnan Yuanmou.We compare the results of the three geo-electric field stations between the normal time with the eve of the Lushan MS7.0earthquake,the results of Chengdu geoelectric field station about the Lushan Ms7.0and Wenchuan Ms8.0earthquakes are also analyzed.We conclude that:(1)HHT method is effective for the data analysis observed by the geo-electric field station,the time-frequency spectrum may be simple and intuitive;(2)About 1~2 months before the Lushan MS7.0earthquake,the energy of geo-electric field enhanced,with period range of approximately 90~1400hours,the minimum amplitude of energy variation is about 3orders of magnitude,the largest ranges up to about 6orders;(3)The credibility of results obtained are greatly enhanced through comparison obtained from the three geo-electric field stations,and analogy obtained from the Chengdu geo-electric field station.In the discussion section of results,we discussed the?situation of seismic electromagnetic signals based on the experimental and numerical simulation method in the domestic and abroad in recent years,these results obtained by them can provide theoretical support to our results in this paper.更多还原