An efficient method to compute the dynamic response
of a fluid-filled crack
Yamamoto, M., Kawakatsu, H.,
Geophys. J. Int.,
submitted, 2007.
The vibration of a fluid-filled crack is considered to be one of the most plausible mechanisms
for the source of long-period events and volcanic tremors occurring around
volcanoes. As a tool to quantitatively interpret source process of such volcanic seismic
signals, we propose a method to numerically simulate the dynamic response of a fluidfilled
crack. In this method, we formulate the motions of the fluid inside and the elastic
solid outside of the crack using boundary integrals in the frequency domain, and solve
the dynamic interactions between the fluid and the elastic solid using the point collocation
method. The present method is more efficient compared to the time-domain
finite difference method which has been used in simulations of a fluid-filled crack, and
enables us to study the dynamics of a fluid-filled crack over a wide range of physical
parameters. The method also allows us to accurately calculate the attenuation factor
of the crack resonance which is an indispensable parameter to estimate the properties
of the fluid inside the crack. The method is also designed to be flexible to many applications
which may be encountered in volcano seismology, and thus extensions of the
method to more complicated problems are promising.