Decomposition of noise wavefield to retrieve shear-wave velocity profile in Colfiorito basin, Italy
عنوان دوره: نوزدهمین کنفرانس ژئوفیزیک ایران
نویسندگان
1دانشجوی دکتری موسسه ژئوفیزیک
2موسسه ژئوفیریک
چکیده
Knowledge about ambient noise wavefield, through decomposition into different participant waves and determination of precise singularities in ellipticity curves, could be very beneficial to improve the obtained subsurface velocity structures. In this paper, a statistical signal processing array method called WaveDec and four single-station methods; Horizontal-to-Vertical Spectral Ratio (HVSR) or H/V, HVTFA (H/V using time frequency analysis), RayDec (Random Decrement Technique) and DOP-E (Degree Of Polarization) are applied to decompose ambient noise wavefield and to extract ellipticity and dispersion curves of surface waves. The Colfiorito basin, Italy, as a site with simple soil structure is considered to apply the methods. The decomposed modes of surface waves and ellipticity curves of Rayleigh waves are used in a joint inversion process. The retrieved shear-wave velocity profile is in close agreement with previous studies in the mentioned site.
کلیدواژه ها
 
Title
Decomposition of noise wavefield to retrieve shear-wave velocity profile in Colfiorito basin, Italy
Authors
Mehrdad Fotouhimehr, Elham Shabani
Abstract
Knowledge about ambient noise wavefield, through decomposition into different participant waves and determination of precise singularities in ellipticity curves, could be very beneficial to improve the obtained subsurface velocity structures. In this paper, a statistical signal processing array method called WaveDec and four single-station methods; Horizontal-to-Vertical Spectral Ratio (HVSR) or H/V, HVTFA (H/V using time frequency analysis), RayDec (Random Decrement Technique) and DOP-E (Degree Of Polarization) are applied to decompose ambient noise wavefield and to extract ellipticity and dispersion curves of surface waves. The Colfiorito basin, Italy, as a site with simple soil structure is considered to apply the methods. The decomposed modes of surface waves and ellipticity curves of Rayleigh waves are used in a joint inversion process. The retrieved shear-wave velocity profile is in close agreement with previous studies in the mentioned site.
Keywords
Ambient noise, Wavefield decomposition, Rayleigh wave Ellipticity, Dispersion, Italy