Abstract
The characteristic frequencies at which two different melt-related attenuation mechanisms occur in partially molten gabbronorite are computed as a function of aspect ratios of the melt-filled cracks, and the melt viscosity. The computations were done for basaltic and andesitic melts. The melt viscosity is constrained by (i) laboratory measurements performed in the range 10(8)-10(14) Pa s with a creep apparatus and in the range 10(-1) to 10(5) Pas with a rotational Couette viscorneter, and (ii) modeling of viscosity at high temperatures. The results of the characteristic frequency calculations suggest that melt squirt flow is a viable attenuation mechanism at seismic frequencies for aspect ratio of melt inclusions in the range 10(-1) to 10(-2) for the andesite, and 10(-4) to 10(-3) for the two basalts.