Brückl, E. „Graphical Location of Seismic Sources Based on Amplitude Ratios“
27.12.2018, SEISMOLOGICAL RESEARCH LETTERS >>> LINK
Methods for location of seismic sources based on amplitudes provide an alternative to standard methods in cases with high ambient noise and emergent, multiple event, or tremor‐type source functions. Numerical methods using amplitudes or amplitude ratios have been described and successfully applied in several previous studies. In this article, a graphical location method based on amplitude ratios is presented, which may be of interest to students and others who want to learn about seismology due of its computational simplicity and the clarity of the solution.
The most basic empirical relation to model the decay of the seismic amplitude maxima with distance is a power law. Given this relation, the ratio of the distances of two seismic stations to the seismic source is uniquely determined by the ratio of the amplitudes recorded at these stations. The geometrical loci of all points with a constant distance ratio is in what is known as an “Apollonius circle” in 2D, and in a sphere with the center and radius of the Apollonius circle in 3D. The graphical location method presented in this article considers the circular intersections of these spheres with a horizontal plane, preferentially in the level of the source location. Data from a low‐cost seismic sensor network in the southern Vienna basin are used to demonstrate the potential application of the method.