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近期的研究结果表明,利用地震P波最初几秒数据测量得到的平均“优势周期”τp,提供了对震级的快速近似估计,该方法能用于地震早期预警系统。尽管以往的研究说明了这种方法的经验价值,本文中我们仍将检测优势周期估计值的理论特性。我们指出,这种估计值是频谱振幅和周期的非线性函数,对大振幅和高频成分赋予了更大的权重。我们的结果还显示,通过递推关系计算得到的、与时间相关的τp最大值估计,在每次单独的测量中都存在固有的误差。在震级的优势周期估计中,尽管一些观测到的变化似乎是缘于局部场地效应,但本文结果表明,估计值的非理想特性也增加了结果的噪声。针对地震早期预警系统潜在的重要性,我们建议应对震级测定所依赖的初始P波数据的频谱特性进行更详细的分析,例如利用多锥形谱或小波方法,有助于设计更好的方法以实现系统性能的进一步优化。
Recent research results show that the average “predominant period ” [tau] p measured from the first few seconds of seismic P wave data provides a fast approximate estimate of the magnitude that can be used in an early warning system for the earthquake. Although previous studies have demonstrated the empirical value of this approach, in this paper we will still examine the theoretical properties of dominance period estimates. We point out that this estimate is a non-linear function of the amplitude and period of the spectrum, giving more weight to large amplitude and high frequency components. Our results also show that the time-dependent τp maximum estimate, calculated by recursion, has inherent errors in each individual measurement. In the predominant period estimates of magnitude, although some of the observed changes seem to be due to local site effects, our results show that the non-ideal nature of the estimates also increases the resulting noise. In view of the potential importance of early warning systems for earthquakes, we suggest that the spectral characteristics of the initial P-wave data on which magnitude measurements depend should be analyzed in more detail, such as the use of multi-cone spectroscopy or wavelet methods to help design better methods Achieve further optimization of system performance.