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Effect of Dipping Layer in Source Energy Distribution of Ambient Noise
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, EAGE-HAGI 1st Asia Pacific Meeting on Near Surface Geoscience and Engineering, Apr 2018, Volume 2018, p.1 - 5
Abstract
Geophysical methods are effective ways to investigate the landslide area. Among them, passive surface wave method is an effective and economic way to measure the shear wave velocity profile especially in large-scale deep-seated landslide case. The influence of topography and dipping layers in the results of it is still not clear. As a preliminary study, we firstly focus on the effect of dipping layers. 3D numerical simulations based on spectral element method were conducted to study the effect. Ambient noises were numerically simulated for 2D array Spatial Autocorrelation method (SPAC) and for 1D array Multichannel Analysis of Passive Surface Wave method (MAPS). According to the results, the bias between the experiment dispersion curve and the theoretical ones in the centre of the array mainly come from the non-uniform source energy distribution. The dispersion curves retrieve from MAPS is much sensitive to the effect than the one from SPAC. The source energy distribution altered by the dipping layers and the dominant azimuth of the source energy would be frequency dependent. A frequency dependent correction can be applied to MAPS but the solution for SPAC needs further study.