Joint magnitude determination and analysis of variance for explosion magnitude estimates
Joint magnitude determination and analysis of variance for explosion magnitude estimates
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爆炸震级估计的联合震级确定和方差分析
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
D. V. Seggern
中科院分区：
文献类型：
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作者：
D. V. Seggern
同时估计台站校正、事件震级和衰减率的最小二乘方法被用作分析爆炸震级方差的基础。这个过程在这里被称为“联合震级测定”（JMD）。将JMD方法应用于来自北美内华达州试验场爆炸台站的地震数据实验室（SDL）数据。由JMD计算的台站震级（MS和m B）的标准差通常是由常规方法计算的震级标准差的一半。这一减少完全是由于增加了车站条件。令人惊讶的是，没有随之而来的减少分散的爆炸MS与m B图是通过使用JMD估计，而不是常规的。为了解决这个矛盾，星等估计的散布被分为三个不同的部分：源，路径站和测量。每个部分的绝对值是从地震测量中得出的，而不使用屈服信息。在抑制了路径-台站效应和测量噪声后，发现源效应对爆炸的震级偏差有显著影响，从而解释了JMD方法不能有效降低MS与m B散射的原因。
abstract A least-squares procedure which simultaneously estimates station corrections, event magnitudes, and an attenuation rate is used as a basis for analyzing the variance of explosion magnitudes. This procedure is here termed “joint magnitude determination” (JMD). The JMD method is applied to Seismic Data Laboratory (SDL) data from North American stations for Nevada Test Site explosions. The standard deviation of station magnitudes ( M S and m b ) computed by JMD for an event typically is one-half of the standard deviation of magnitudes computed by routine methods. This reduction is wholly due to the addition of station terms. Surprisingly, no consequent reduction in scatter of the explosion M S versus m b plot was attained by using JMD estimates rather than routine ones. To resolve this paradox, the scatter of magnitude estimates is divided into three distinct parts: source, path-station, and measurement. The absolute value for each part is derived from the seismic measurements without using yield information. After path-station effects and measurement noise are suppressed, it is found that source effects contribute significantly to magnitude bias for explosions, thus explaining the failure of the JMD method to reduce M S versus m b scatter.