Surface-Wave Analysis Beyond the Dispersion Curves: FVS

Abstract

The FVS (Full Velocity Spectrum) approach is a way to analyze the dispersion of surface waves recorded according to active methodologies. The goal is go beyond the classical and problematic approach based on the (interpreted) modal dispersion curves that, in some cases, can be difficult or impossible to be defined. In the classical approach, the velocity spectrum is interpreted in terms of modes (fundamental and/or higher modes). Therefore, we do not invert something “objective” but a subjective interpretation. The same velocity spectrum can be interpreted in different ways and, consequently, lead to different solutions. The FVS approach considers the whole frequency-velocity matrix without any interpretation in terms of modal curves. A series of single- and multi-component examples are presented. In this Chapter we will focus on the phase velocities obtained from multi-offset data but in the Chap. 4 we will see how to efficiently exploit the FVS approach in case of single-offset data (HoliSurface approach).

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Ludwig Wittgenstein (Philosophical Investigations)