HR: 0800h
AN: H31D-0419    [Abstracts]
TI: Low-frequency dilatational wave propagation through unsaturated porous media containing two immiscible fluids
AU: * Lo, W
EM: lowc@uclink.berkeley.edu
AF: Department of Geophysics, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 United States
AU: * Lo, W
EM: lowc@uclink.berkeley.edu
AF: Department of Civil and Environmental Engineering,, University of California, Berkeley,, Berkeley, CA 94720 United States
AU: Sposito, G
EM: gsposito@nature.berkeley.edu
AF: Department of Civil and Environmental Engineering,, University of California, Berkeley,, Berkeley, CA 94720 United States
AU: Majer, E
EM: ELMajer@lbl.gov
AF: Department of Geophysics, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 United States
AB: The quantitative description of elastic wave propagation in an elastic porous medium containing two immiscible fluids is one of the classic problems in the physics of flow through unsaturated porous materials. An analytical theory of the low-frequency behavior of dilatational waves propagating through such a porous medium is presented based on the Berryman-Thigpen-Chin (BTC) model, in which capillary pressure effects are neglected. We show that the BTC equations in the frequency domain can be transformed, at sufficiently low frequencies, into a dissipative wave equation (telegraph equation) and a propagating wave equation in the time domain. These partial differential equations describe two independent modes of dilatational wave motion that are analogous to the Biot fast and slow compressional waves in a single-fluid system. The equations can be solved analytically under a variety of initial and boundary conditions.
DE: 3210 Modeling
DE: 1875 Unsaturated zone
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting