Modelling the response of seismic wavefields to sharp lateral variations in crustal discontinuities is essential for seismic tomography application and path effects correction in earthquake source characterization. This is particularly relevant when wavefields cross back-arc oceanic basins, i.e. mixed continental-oceanic settings. High-frequency (>0.05 Hz) seismic waves resonate and get absorbed across these settings due to a shallow Moho, crustal heterogeneities, and energy leakage. Here, we provide the first high-frequency wave-equation model of full seismograms propagating through realistic 3D back-arc basins. Inversion by parameters trial based on correlation analyses identifies P-, S- and coda-wave as attributes able to estimate jointly 3D Moho variations, sediment thickness, and earthquake source characteristics using data from a single regional earthquake. We use as data waveforms produced by the Accumoli earthquake (Central Italy, 2016), propagating across the Southern Tyrrhenian basin and recorded across Southern Italy. The best model comprises a deep Moho (\(\sim\)18 km) in the middle of the basin and a crustal pinch with the continental crust in Sicily. The deep Moho corresponds to the Issel Bridge, a portion of continental crust trapped between the Vavilov and Marsili volcanic centres. The Accumoli earthquake is optimally described at a depth of 7.3 km using a boxcar with rise time of 6 s. Our results show that the early S-wave coda comprises trapped and reverberating phases sensitive to crustal interfaces. Forward modelling these waves is computationally expensive; however, adding these attributes to tomographic procedures allows modelling both source and structural parameters across oceanic basins.

模拟地震波场对地壳间断面急剧横向变化的响应对于地震层析成像应用和地震源特征中的路径效应校正至关重要。当波场穿过弧后海盆时，即大陆-海洋混合环境，这一点尤为重要。由于浅莫霍面、地壳异质性和能量泄漏，高频 (>0.05 Hz) 地震波在这些环境中产生共振并被吸收。在这里，我们提供了第一个通过逼真的 3D 弧后盆地传播的完整地震图的高频波动方程模型。基于相关分析的参数试验反演将 P 波、S 波和尾波识别为能够联合估计 3D 莫霍面变化、沉积物厚度、和震源特征，使用来自单个区域地震的数据。我们使用 Accumoli 地震（意大利中部，2016 年）产生的数据波形，传播到南第勒尼安盆地并记录到整个意大利南部。最好的模型包括一个深莫霍面（\(\sim\) 18 km) 在盆地中部，在西西里岛与大陆地壳夹点。深层莫霍面对应于伊塞尔桥，这是位于瓦维洛夫和马西里火山中心之间的大陆地壳的一部分。Accumoli 地震在 7.3 公里的深度使用上升时间为 6 秒的棚车进行了最佳描述。我们的研究结果表明，早期 S 波尾波包括对地壳界面敏感的捕获相和混响相。对这些波进行正向建模在计算上非常昂贵；然而，将这些属性添加到断层扫描程序中可以对跨大洋盆地的源参数和结构参数进行建模。