Geophysical Journal International · 1976 · 44 citations · 20 references
Natural SciencesEarth SciencesGeophysicsEarthquake PhysicsSeismologyVibrationEarthquake Ground MotionStrong-motion SeismologyEarthquakesFree OscillationsLong-period EarthquakesLong-period Seismic EventsQuality FactorsVery-long-period Seismic Events
Summary Free periods and damping of spheroidal and toroidal oscillations extracted from spectra of 16 large earthquakes recorded in the long-period French stations are determined. Fundamental modes and a few overtones are studied in the range from 100 to 600 s. For the fundamental modes the estimations of phase velocities are path dependent. Their quality factors, obtained with a good precision due to the method of analysis, show more complex variations. Estimations of Q are also presented for overtones.
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