The analysis of how an earthquake is felt was addressed with the data provided by citizens through a website dedicated to the perception of earthquakes in Italy (Data and Resources). The analysis focused on the perception of earthquakes by observers inside both parked and moving cars. These situations were compared with outdoor ones. The felt percentage of each situation was quantified for epicentral distance ranges and European Macroseismic Scale (EMS) degree. One of the main findings was the greatest sensitivity to shaking for people inside parked cars due to resonance phenomena of the automobile–observer system. The distribution of the intensity of perception in the car was analyzed as a function of the hypocentral distance and the magnitude of the earthquake. It was possible to define the attenuation trends of these intensities. The comparison of these trends with those of the equations for estimation of response spectral ordinates allowed us to have an evaluation of the frequency values of the seismic waves that caused the vibrations felt, which were found to agree with the typical frequencies of the car–observer system, as highlighted by independent studies. The results of this analysis show the possibility to include the perception of the earthquake inside a parked and moving car among the diagnostics used in the definition of macroseismic intensity degree of the EMS.

中文翻译：

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车内有地震感觉吗？

市民通过专门了解意大利地震的网站（数据和资源）提供的数据，对地震的感受进行了分析。分析着重于观察者对停放的汽车和正在行驶的汽车内的地震的感知。将这些情况与室外情况进行了比较。根据震中距离范围和欧洲宏观地震标度（EMS）程度量化每种情况的感觉百分比。主要发现之一是由于汽车观察者系统的共振现象，使停在车内的人对震动的敏感性最高。分析了汽车中感知强度的分布与震中距离和地震强度的关系。可以定义这些强度的衰减趋势。将这些趋势与用于估计响应频谱纵坐标的方程式进行了比较，从而使我们能够对引起感觉到的振动的地震波的频率值进行评估，发现该地震波的频率值与汽车观察者的典型频率一致如独立研究所强调的那样。分析的结果表明，在定义EMS的大地震烈度时所使用的诊断方法中，有可能将对停放和行驶中的汽车内部的地震的感知包括在内。正如独立研究所强调的那样。分析的结果表明，在定义EMS的大地震烈度时所使用的诊断方法中，有可能将对停放和行驶中的汽车内部的地震的感知包括在内。正如独立研究所强调的那样。分析的结果表明，在定义EMS的大地震烈度时所使用的诊断方法中，有可能将对停放和行驶中的汽车内部的地震的感知包括在内。