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The dependence of acoustic properties of a crack on the resonance mode and geometry
Author(s) -
Kumagai Hiroyuki,
Chouet Bernard A.
Publication year - 2001
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2001gl013025
Subject(s) - dimensionless quantity , resonance (particle physics) , mode (computer interface) , materials science , geometry , waveform , acoustic resonance , geology , mechanics , physics , mathematics , computer science , particle physics , quantum mechanics , voltage , operating system
We examine the dependence of the acoustic properties of a crack containing magmatic or hydrothermal fluids on the resonance mode and geometry to quantify the source properties of long‐period (LP) events observed in volcanic areas. Our results, based on spectral analyses of synthetic waveforms generated with a fluid‐driven crack model, indicate that the basic features of the dimensionless frequency (ν) and quality factor ( Q r ) for a crack containing various types of fluids are not strongly affected by the choice of mode, although the actual ranges of Q r and ν both depend on the mode. The dimensionless complex frequency systematically varies with changes in the crack geometry, showing increases in both Q r and ν as the crack length to aperture ratio decreases. The present results may be useful for the interpretation of spatial and temporal variations in the observed complex frequencies of LP events.