Premium
Determining hydrological and soil mechanical parameters from multichannel surface‐wave analysis across the Alpine Fault at Inchbonnie, New Zealand
Author(s) -
Konstantaki L.A.,
Carpentier S.,
Garofalo F.,
Bergamo P.,
Socco L.V.
Publication year - 2013
Publication title -
near surface geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.639
H-Index - 39
eISSN - 1873-0604
pISSN - 1569-4445
DOI - 10.3997/1873-0604.2013019
Subject(s) - geology , seismology , surface wave , inversion (geology) , water table , hydrogeology , s wave , slip (aerodynamics) , discontinuity (linguistics) , geotechnical engineering , groundwater , tectonics , optics , physics , thermodynamics , mathematical analysis , mathematics
Combining S‐wave data, resulting from surface‐wave dispersion analysis with P‐wave tomographic data, is a valuable tool to improve the understanding of near‐surface soil properties and allows the estimation of soil mechanical parameters and the determination of the depth of the water table. To achieve this combination of methods in a complex fault zone setting, active‐source seismic data were acquired at Inchbonnie, New Zealand across the Alpine Fault. This is a major transpressional strike‐slip fault that has generated magnitude > 7.8 earthquakes in the past. In this study, we focus on the surface‐wave component of these data, to determine elastic parameters for the shallow (~60 m) subsurface as well as the depth of the water table. We achieve this by combining S‐wave velocity models from surface‐wave dispersion curve inversion and P‐wave velocity models obtained from traveltime tomographic inversion in a previous study. The surface‐wave dispersion curve inversion is done by means of a laterally constrained inversion algorithm. As a result, we are able to obtain elastic parameters and map the water table and the geology around the Alpine Fault at Inchbonnie, New Zealand. The Alpine Fault itself appears as a relatively sharp lateral discontinuity in all investigated parameters.