This study focuses on the vibrational response of a landslide mass to natural and man-induced vibrations. The landslide is located in the Molise region (Italy) and involves a coastal slope extending approximately 5 km², from the Petacciato village to the coastline. The landslide activity is well documented since 1909 with historical reactivations and resulted in severe damage to infrastructure and to the ancient village. This activity is characterised by a roto-translational mechanism involving blue clays, sands, and conglomerates of Pleistocene age. A multitemporal geomorphological analysis of the landslide activity allowed us to detect a retrogressive style corresponding to the crown area as well as a prograding toe that reaches the submerged nearshore. Seismic ambient noise measurements revealed that the local seismic amplification is strictly concentrated in the back-crown area, i.e., the area affected by the most recent retrogressive effects of the landslide mass. Moreover, ground vibrations generated by train transits were analysed to identify possible amplification phenomena of dynamic external input, that can occur inside the landslide mass with respect to the surrounding area. Therefore, a Spectral Aggravation Index (SAI) was defined by the ratio between the Fourier spectrum during train transit and that obtained for an equal time window in the absence of train traffic sources. The SAI was applied to compare the response to man-induced vibrations inside the landslide mass with the one outside, by computing a ratio of the SAI at different measurement points inside/outside the landslide mass. The obtained results highlight the intense activity of the landslide both in space and time, revealing a joining between the ongoing retreat areas, surveyed by multitemporal geomorphological analysis, and local seismic response, by geophysical investigations. On the other hand, most of the landslide mass from the middle- to downslope position is not resonant and its higher damping causes a lower intensity of ground motion in response to man-induced vibrations with respect to the surrounding areas.

本研究侧重于滑坡体对自然和人为振动的振动响应。滑坡位于莫利塞地区（意大利），涉及延伸约 5 公里^{2的海岸斜坡}，从 Petacciato 村到海岸线。自 1909 年以来，山体滑坡活动有据可查，历史重新激活，并对基础设施和古村落造成严重破坏。该活动的特点是涉及更新世时代的蓝色粘土、沙子和砾岩的旋转平移机制。对滑坡活动的多时相地貌分析使我们能够检测到与冠部区域相对应的倒退样式以及到达被淹没的近岸的前进坡脚。地震环境噪声测量表明，局部地震放大严格集中在后冠区域，即受滑坡体最近退行效应影响的区域。而且，分析了火车运输产生的地面振动，以确定动态外部输入的可能放大现象，这种现象可能发生在滑坡体内部相对于周围区域。因此，光谱恶化指数 (SAI) 定义为火车运输过程中的傅里叶光谱与在没有火车交通源的情况下在相同时间窗口获得的光谱之间的比率。通过计算滑坡体内部/外部不同测量点的 SAI 比率，应用 SAI 比较滑坡体内部和外部对人为振动的响应。获得的结果突出了滑坡在空间和时间上的强烈活动，揭示了正在进行的撤退区域之间的连接，通过多时相地貌分析进行调查，和当地的地震响应，通过地球物理调查。另一方面，从中坡位置到下坡位置的大部分滑坡体不是共振的，并且其较高的阻尼会导致地面运动的强度较低，以响应相对于周围区域的人为振动。