## 7 Conclusions  
(1) The presence of the earth fissure significantly amplifies the peaks of the direct Fourier spectra, the acceleration response spectra, and the Arias intensity within the site. In particular, the peaks of each spectrum increased dramatically in the range of 5 m immediately on either side of the fissure. (2) The amplification effect at the fissure site follows the pattern of steep increase in the near field, slow rise in the middle field, and steady rise in the far field. Areas with amplification factors higher than 1.5 showed a steep rise in amplification, with both spectral and intensity peaks rapidly increasing to several times the original site and eventually reaching extreme values at the outcrops of the fissures. Areas with an amplification factor \begin{table}
\begin{tabular}{l l l} \hline  & **Hanging Side** & **Heading Side** \\ \hline Fourier & 2.1 & 1.8 \\ Response & 1.8 & 1.6 \\ Arias & 3.2 & 2.9 \\ \hline \end{tabular}
\end{table} 
Table 1: The extreme value of the amplification factor of each analysis method. \begin{table}
\begin{tabular}{l l l l} \hline  & **Hanging Side** & **Heading Side** \\ \hline Amplification factor & 1.5 & 1 & 1.5 & 1 \\ Fourier & 7.1 m & 21.2 m & 5.9 m & 20.0 m \\ Response & 5.0 m & 18.5 m & 3.8 m & 18.0 m \\ Arias & 13.3 m & 23.9 m & 9.2 m & 17.3 m \\ \hline \end{tabular}
\end{table} 
Table 2: The influence range of each analysis method. between 1.5 and 1 are zones with a slow rise of the amplification effect, and the dynamic response of the site is still affected by the fissures. (3) The amplification of the dynamic response of an earth fissure site with positive fault characteristics has a significant \"hanging side effect.\" The amplification factor is often higher in the steep rise zone of the hanging side, and the hanging side has a further influence range. (4) In the actual seismic fortification of the project, it is necessary to avoid the area where the amplification factor rises sharply. Alternatively, the strength of structures and foundations in the area should be increased, and additional seismic fortification measures should be taken. In areas where the amplification factor rises slowly, the seismic fortification level of the structure should also be strengthened according to the amplification factor, so that it can withstand 1.5 times the expected seismic factor. In this study, based on the microtremor test, typical earth fissures in the Yuncheng Basin of China were taken as the research objects, and dynamic amplification patterns at earth fissure sites were systematically revealed using spectral characterization of the microtremors. We propose preliminary seismic fortification for different dynamic amplification areas. This study provides a reference for the seismic fortification of sites with similar engineering conditions and the subject of seismic amplification effect in similar sites. In addition, the numerical simulation of seismic responses of fissure sites and different structures is expected to further improve the results of the amplification effect and provide more detailed suggestions for seismic fortification under different seismic intensities. Conceptualization, Y.D. ; Software, G.C. ; Investigation, G.C., J.C., Y.X. and N.H.; Writing--original draft, G.C. ; Writing--review & editing, G.C., Y.D. and H.M.; Supervision, Y.D. ; Funding acquisition, Y.D. and H.M. All authors have read and agreed to the published version of the manuscript. This research was funded by [National Natural Science Foundation of China] grant number [417/2275], [Fundamental Research Funds for the Central Universities] grant number [300102268203], [Scientific Research Plan Projects of Shaanxi Education Department] grant number [20K0801], [Natural Science Basic Research Program of Shaanxi Province] grant number 2022 JQ-289, [Fundamental Research Funds for the Central Universities] grant number 300102262505, and [Key Research and Development projects of Shaanxi Province] grant number 2022 SF-197. Not applicable.