A METHOD TO IDENTIFY MODAL PROPERTIES OF SMALL-SCALED SEDIMENTARY BASIN

Abstract

 A few studies reported that a mode is formed within sedimentary basins. We apply the frequency domain decomposition technique to microtremor data observed on a sediment filled valley. Several dominant frequencies of the singular value spectra are identified, however, some of them are affected by the frequency characteristics of input motions. To distinguish vibration characteristics from some noise at the dominant frequencies of singular value spectra, we compare the Fourier spectra of the microtremor records on the base rock with singular value spectra. Identified vibration modes are compared with those obtained through eigenvalue analysis by a finite element method.