AlpsLig-crust_WET

AlpsLig-crust_WET is a 3-D high-resolution shear-wave velocity model of the Alps and the Ligurian sea derived from ambient-noise wave-equation tomography (WET). Observed waveforms consist of vertical-component noise correlations from 600 broadband stations in the Alps and surroundings, including ocean-bottom seismometers (OBS) of the AlpArray temporary network in the Ligurian sea. The WET uses a frequency-dependent phase traveltime misfit function in an iterative procedure to refine the 3-D Vs model by Nouibat et al. (2022) computed from a Bayesian two-step ambient noise tomography (ANT). In the long-period band (20-85 s), an elastic approximation is considered, while in the 5-20 s band, we account for the effect of water layer in the Ligurian sea by applying a fluid-solid coupling for acoustic-elastic waveform simulations. The resulting Vs model enhances the shape and contrast of velocity structures, accounting for 3-D and finite-frequency effects. For more details, please refer to Nouibat et al., 2023 (DOI: 10.1029/2023JB026776).

AlpsLig-crust_WET是一款面向阿尔卑斯山脉与利古里亚海的三维高分辨率剪切波速度（shear-wave velocity, Vs）模型，其构建基于环境噪声波动方程层析成像（ambient-noise wave-equation tomography, WET）。该模型的观测波形数据源自阿尔卑斯山脉及周边区域600个宽频带台站的垂直分量噪声互相关函数，其中包含利古里亚海地区AlpArray临时台阵的海底地震仪（ocean-bottom seismometers, OBS）观测数据。该WET方法采用依赖于频率的相位走时残差函数，通过迭代流程对Nouibat等人2022年基于贝叶斯两步法环境噪声层析成像（Bayesian two-step ambient noise tomography, ANT）构建的三维Vs模型进行精细化修正。在长周期波段（20~85秒）中，模型采用弹性近似假设；而在5~20秒波段，为刻画利古里亚海水层的影响，研究人员针对声-弹性波形模拟应用了流固耦合方案。最终得到的Vs模型能够更精准地还原速度结构的形态与速度反差，同时兼顾三维效应与有限频效应。如需获取更多细节，请参阅Nouibat等人2023年的研究成果（DOI: 10.1029/2023JB026776）。