分数维在地磁方法中的应用
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摘要
本文将关联维的Ｇ—Ｐ法尝试在地磁方法中应用。首先消除外空场的影响，使数据的变化代表地磁场的变化；１２个月为一窗口，滑动步长６个月，以１９９３年１２月３１日烟台ＭＬ４．８级地震为震例，求分维值。结果表明：地磁场垂直分量的时间序列存在分维结构，而且地震前有明显降维现象。
The G-P method of association dimension is trying to be used in geomagnetic method. At first, the influence from external space is removed, which makes the data represent the variation of geomagnetic variation. Taking the Yantai earthquake of M=4.8 on Dec. 31 of 1993 as an example, with a window of 12 motnths and steps of 6 month, the fractal values were calculated. The results show that there exists fractal structure in time sequence in geomagnetic vertical component, showing clear dimension reduction before earthquake.
The G-P method of association dimension is trying to be used in geomagnetic method. At first, the influence from external space is removed, which makes the data represent the variation of geomagnetic variation. Taking the Yantai earthquake of M=4.8 on Dec. 31 of 1993 as an example, with a window of 12 motnths and steps of 6 month, the fractal values were calculated. The results show that there exists fractal structure in time sequence in geomagnetic vertical component, showing clear dimension reduction before earthquake.
引文
〔1〕陈．探索地震前兆的复杂性．分形与分维在地球科学中的应用．北京：学术期刊出版社，1988〔2〕李后强．分形与分维—探索复杂性的新方法．成都：四川教育出版社，1990〔3〕赵和云．地电阻率的分数维及其前兆特征．地震，1992，（1）〔4〕陆远忠．用时间序列从建复杂系统动力学初探．中国地震，1993，（1）〔5〕洪时中．一种客观确定分形“无标度区”的方法—自相似比法．大自然探索，1993，（1）〔6〕洪时中．用Grassberger—Procaccia法计算吸引子维数的基本限制．物理学报，1994，43（8）
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