%A"Yamamoto, H" %A"Mizutani, K" %A"Saito, t [Iwate University, Iwate (Japan). Faculty of Engineering]" %D1997 %I; Society of Exploration Geophysicists of Japan, Tokyo (Japan) %2 %J[] %K44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS, 58 GEOSCIENCES, RAYLEIGH WAVES, AMPLITUDES, SEISMOGRAPHS, SEISMIC ARRAYS, EIGENFREQUENCY, SEISMIC SOURCES, INDUSTRIAL PLANTS, SUBSURFACE STRUCTURES, AMPLIFIERS, RECORDING SYSTEMS %PMedium: ED; Size: pp. 40-44 %TEstimation of Rayleigh-wave spectral ratio from microtremors using a three-component single-station seismograph; Itten sanseibun bido kansoku ni motozuita Rayleigh ha shinpukuhi no suitei %XDiscussions were given on the possibility of estimating Rayleigh-wave spectral ratio utilizing phase difference between horizontal movements and vertical movements by using a three-component single-station seismograph. The test has selected as an observation point a location in the city of Kushiro where a pulp and paper mill generating microtremors is the focal point, and the underground structure at that point has been estimated by using the vertical array observation method. The observation system has used three components of a velocity type seismograph having a natural period of one second, an amplifier and an analog data recorder. As a result of the discussions, the following matters were made clear: the spectral ratio with a phase difference of 90 degrees agrees with the frequency at a peak trough of the theoretical Rayleigh-wave spectral ratio; the values of the spectral ratio at the phase difference of 90 degrees and the values of the theoretical Rayleigh-wave spectral ratio correspond well excepting in frequency bands of the peak trough; and these results suggest that the Rayleigh-wave spectral ratio may be estimated by utilizing the phase difference between horizontal movements and vertical movements. Estimation of the underground structure by using the inverse analysis of this Rayleigh-wave spectral ratio is expected in the future. 6 refs., 5 figs., tab. %0Conference %NETDE/JP-98751022; CONF-9710214-;Other: ON: DE98751022; TRN: JN97G4521 %1 %CJapan %Rhttps://doi.org/ Other: ON: DE98751022; TRN: JN97G4521 NEDO %GJapanese