The dispersive velocity of compressional waves in magmatic suspensions

SUMMARY The geophysical detection of magma bodies and the estimation dimensions, physical properties volume fraction each phase composing is required to improve forecasting volcanic hazards understand transcrustal magmatism. We develop an analytical model calculate P waves velocity in a three-phase consisting crystals gas bubbles suspended viscous melt. apply our speed sound as function temperature three magmas with different chemical compositions, representative diversity that encountered arc employs coupled theory explicitly accounts for exchanges momentum heat between phases. show varies nonlinearly frequency acoustic perturbation two theoretical bounds. dispersion results from exchange melt dispersed phases affects magnitude their thermal expansions. lower bound occurs at low frequencies which all constituents can be considered equilibrium, whereas upper high may neglected. presence produces sharp decrease compressional generates conditions significant usually geophysics. Finally, we compare estimates ones published relationships. Differences are largest higher <10 per cent typical magma.