Abstract
Abstract The Horizontal-to-Vertical (H/V) spectral ratio method uses continuous ambient noise records has been used extensively to study the characteristics of site response due to the earthquake occurrence. Sources of ambient noise are usually from human activities or natural excitations and might be composed of body and surface wave components. Several studies have investigated the possibility to extract information on the shallow subsurface model from the inversion of H/V spectral ratio. In this study, we investigated the shallow subsurface velocity model below two broadband seismometers at Simeulue Island, Aceh. Two broadband seismometers of PUTR and LEWK were selected because of the relatively clear peak amplitude of H/V spectral ratios, which may reflect the existence of strong impedance contrast. The initial models are set to be fixed of five homogeneous medium layers with the last medium to be infinite homogeneous medium. By setting fixed layer boundaries in the inversion process, the velocities in the medium may vary to obtain the most suitable fitting to the observed H/V spectral ratio. From the inversion process, we suggest we suggest that the strong impedance contrasts may occur on the shallow part of the medium at 2 up to 15 m depth. Keywords: ambient noise records, H/V spectral ratio, inversion process.
Highlights
Site response, which is a response of a site to an incoming earthquake shaking, give important information on the site amplification factors
Nakamura introduced H/V spectral ratio (HVSR) method, which measured the horizontal to vertical spectral ratio of ambient seismic noise records, to obtain information of the site response [3, 4]
Malischewsky et al in [14] carried out analytical studies to obtain the correlation between H/V spectral ratio and Rayleigh ellipticity assuming noise wavefield consists of Rayleigh waves [14]
Summary
Site response, which is a response of a site to an incoming earthquake shaking, give important information on the site amplification factors. Nakamura introduced H/V spectral ratio (HVSR) method, which measured the horizontal to vertical spectral ratio of ambient seismic noise records, to obtain information of the site response [3, 4]. Malischewsky et al in [14] carried out analytical studies to obtain the correlation between H/V spectral ratio and Rayleigh ellipticity assuming noise wavefield consists of Rayleigh waves [14]. They found that the frequency peak on the H/V spectral ratio curve corresponds to the shear wave resonance in the medium layer.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
