The Experimental Study and Simulation of Volcanic Structures Using Active Vibroseismic Methods

This paper is a review of our work, an experimental study and simulation of seismic fields in volcanic structures using vibrators as sources of elastic waves. We review the results of experimental studies of mud volcanoes carried out by the Institute of Computational Mathematics and Mathematical Geophysics (ICM&MG) of the Siberian Branch (SB), Russian Academy of Sciences (RAS); by the Institute of Physics of the Earth (IPE), RAS; and by the Kuban State University in the Taman mud-volcanic province using vibrators. We have carried out mathematical simulation in heterogeneous geophysical media to refine the information on the structure of the object under investigation, as well as on the distinguishing features of the seismic field. We have developed a mathematical approach to deal with the simulation of vibroseismic probing of mud volcanoes with arbitrary geometries incorporating knowledge of deep-seated faults, overlapping layers, and so on. Numerical techniques were used to solve sets of equations in elasticity theory and to develop parallel algorithms, program packages, as well as carrying out numerical experiments in high-performance computational systems. We present results from calculations of the seismic field for the source zone of the Shugo mud volcano. This paper describes 3D and 2D geophysical models developed for this study and the results of simulation for the seismic field of the Karabetova Gora mud volcano and for the Elbrus magmatic volcano. It is shown that the approach developed here using active vibroseismic techniques can be successfully used in practice to refine the seismic field, the deep structure of geophysical models, and to study the effects exerted by the geometry of a magma chamber and by the presence of erupting channels on data acquired by an observation system on the ground surface. These studies prove that vibroseismic sources with high accuracies of periodic excitation can be used to study volcanic structures and to conduct active monitoring of volcanic activity.