Southeastern Section - 64th Annual Meeting (19–20 March 2015)

Paper No. 5
Presentation Time: 8:00 AM-12:00 PM


FISCHER, Brian C., School of Geoscience, University of Louisiana at Lafayette, Lafayette, LA 70504 and MORRA, Gabriele, University of Louisiana at Lafayette, Department of Physics, Lafayette, LA 70504,

Long period volcanic seismic signals have been used to monitor and predict eruptions. Less is known on their use for the exploration of the interior dynamics of a volcanic system. Not that such a notion hasn't been explored, but that is where there is more to discover at the present time.

One of the aspects found to affect the resonance that produces long period signals is the presence of gas bubbles in magma. They act as resonators, like the body of a guitar. In order to better understand precisely how bubbles affect the resonant signals, the behavior of the bubbles must be understood better. The different aspects of bubble behavior that need to be modeled include the nucleation of the bubbles and their dynamics.

We employ boundary element methods to model this phenomenon. This powerful approach needs several improvements such as the implementation of a stable surface tension, of an exsolution algorithms. These tools will be used to model the gas flow into the bubble, which drives their growth, and the growth due to decompression with bubble rise. We aim at reproducing the fragmentation into many smaller bubbles, which has been observed in laboratory experiments, and that would greatly increases the surface area and therefore the rate of exsolution.

When the behavior of the bubbles is known more precisely, then their effects on resonation can be modeled. This should give greater insight on how the volcanic system functions, and allow for further progress in the interpretation of long period seismic signals.