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Acoustic fluidization - A new geologic processA number of geologic processes, particularly seismic faulting, impact crater slumping, and long runout landslides, require the failure of geologic materials under differential stresses much smaller than expected on the basis of conventional rock mechanics. This paper proposes that the low strengths apparent in these phenomena are due to a state of 'acoustic fluidization' induced by a transient strong acoustic wave field. The strain rates possible in such a field are evaluated, and it is shown that acoustically fluidized debris behaves as a newtonian fluid with a viscosity in the range 100,000 to 10,000,000 P for plausible conditions. Energy gains and losses in the acoustic field are discussed, and the mechanism is shown to be effective if internal dissipation in the field gives a Q approximately greater than 100. Whether such values for Q are realized is not known at present. However, acoustic fluidization provides a qualitatively correct description of the failure of rock debris under low differential stresses in the processes of faulting, crater slumping, and long runout landslides. Acoustic fluidization thus deserves serious consideration as a possible explanation of these phenomena.
Document ID
19800036019
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Melosh, H. J.
(California Institute of Technology Pasadena, Calif., United States)
Date Acquired
August 10, 2013
Publication Date
December 10, 1979
Publication Information
Publication: Journal of Geophysical Research
Volume: 84
Subject Category
Geophysics
Accession Number
80A20189
Funding Number(s)
CONTRACT_GRANT: NSG-7316
Distribution Limits
Public
Copyright
Other

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