Radially anisotropic S-wave structures under the permanent seismic stations in Australia are reconstructed using multimode surface waves (SWs) and receiver functions (RFs) in a framework of the Bayesian inference. We have developed a fully nonlinear method of joint inversions incorporating P-RFs and multimode Rayleigh and Love waves, based on the transdimensional Hierarchical Bayesian formulation. The method allows us to estimate a probabilistic Earth model taking account of the complexity and uncertainty of Earth structure, by treating the model parameters and data errors as unknowns. The Parallel Tempering algorithm is employed for the effective parameter search based on the reversible-jump Markov Chain Monte Carlo method. The use of higher modes enables us to enhance the sensitivity to the depth below the continental asthenosphere. Synthetic experiments indicate the importance of higher mode SWs for the better recovery of radial anisotropy in the whole depth range of the upper mantle. The method is applied to five Global Seismographic Network stations in Australia. While the S-wave models in eastern Australia show shallow lithosphere–asthenosphere boundary (LAB) above 100 km depth, those in central and Western Australia exhibit both mid-lithosphere discontinuities (MLDs) and LAB. Also, seismic velocity jumps equivalent to the Lehmann discontinuity (L-D) are found in all seismic stations. The L-D under the Australian continents is found at around 200–300 km depth, depending on locations. Radial anisotropy in the depth range between LAB and L-D tends to show faster SH anomalies, which may indicate the effects of horizontal shear underneath the fast-moving Australian plate.

中文翻译：

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使用多模表面波和接收器函数通过多维贝叶斯反演实现澳大利亚下方的上地幔不连续性

在贝叶斯推断的框架内，使用多模表面波（SW）和接收函数（RF）重建了澳大利亚永久地震台站下方的径向各向异性S波结构。我们开发了一种完全非线性的联合反演方法，并结合了P-RF和多模Rayleigh和Love波，基于多维层次贝叶斯公式。通过将模型参数和数据误差视为未知数，该方法使我们能够考虑地球结构的复杂性和不确定性来估计概率地球模型。基于可逆跳马尔可夫链蒙特卡罗方法，采用并行回火算法进行有效参数搜索。使用更高的模式使我们能够增强对大陆软流圈以下深度的敏感性。合成实验表明，较高模态的SW对于在上地幔整个深度范围内更好地恢复径向各向异性具有重要意义。该方法已应用于澳大利亚的五个全球地震台网。而S澳大利亚东部的波模型显示了深度超过100 km的浅岩石圈-软流圈边界（LAB），澳大利亚中部和西部的波模型同时显示了中岩圈中部的不连续性（MLD）和LAB。此外，在所有地震台站中都发现了相当于雷曼不连续性（LD）的地震速度跳跃。根据不同的地理位置，澳大利亚大陆下的LD深度约为200-300 km。在LAB和LD之间的深度范围内，径向各向异性倾向于表现出更快的SH异常，这可能表明在快速移动的澳大利亚板块下方水平剪切的影响。