摘要
本文采用标度变换法分析了宁夏灵武、吴忠地区1971年以来发生的、有较完整的仪器记录的4次中强地震序列的时间分维D_0,发现前震序列或双震序列的第2次主震前的地震时间分维低于余震序列,序列的P值及b值亦具同步变化。初步认为,研究地震序列的时间分维结构可能有助于对其短期趋势的估计。本文还对有关问题进行了讨论。
In this paper, the time fractals (D) for four moderately strong earthquake sequences are analysed using box counting algorithm. The four sequences have taken place in Lingwu-Wuzhong area of Ningxia since 1971 and have been recorded accurately. The results show that the time fractals are low (D<0.5) in this area. For the double main shock sequence or foreshock sequence, the fractal obtained before the second main shock occurrence is lower than that obtained from aftershock sequence. We have also analysed the frequency attenuation features of four earthquake sequences. It shows that the attenuation coefficient P and b value have synchronous variation. Therefore, we think that the earthquake sequence time fractal may be helpful for judging earthquake tendency in a short period.
出处
《西北地震学报》
CSCD
1990年第2期42-48,共7页
Northwestern Seismological Journal