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用于表征估计地震动的衰减关系经常忽略地球高度可变的三维速度和衰减结构的细节。日益增多的可用衰减模型可用于使预期地震动更为精确。首先,我进行了一些测试以察看像地壳衰减、上地幔衰减和地壳厚度等几个参数变化的影响。然后,使用最近中东地区地壳和上地幔的衰减模型的结果提供一个具体例子。发现相同事件不同方向记录的1Hz谱加速度变化了30%～40%。因为区域整体变化性预计会更高,这种影响太显著了,在地震动估计和地震灾害评估中不能忽视。这就有可能要计算在广泛使用的一维衰减关系中没有考虑的较小尺度的一些振幅变化。
The attenuation relationships used to characterize the estimated ground motion often neglect the details of the three-dimensional speed and attenuation structures of the earth’s height. Increasingly available attenuation models are available to make the expected ground motion more accurate. First, I conducted some tests to see the effects of several parameter changes like crustal attenuation, upper mantle attenuation and crustal thickness. Then, a concrete example is given using the results of the decay model of the recent Middle East crust and upper mantle. It was found that the 1 Hz spectrum acceleration recorded in different directions of the same event changed by 30% ~ 40%. Because the overall regional variability is expected to be higher, the impact is too significant and can not be ignored in the assessment of earthquake motion and earthquake disasters. This makes it possible to calculate some amplitude variations of smaller scales that are not considered in the widely used one-dimensional decay relation.