Revisiting the Hungarian Seismoacoustic Bulletins

Hungary's first and only infrasound station has been operating in Piszkéstető since 2017. During its eight years of operation, it has recorded numerous events, including quarry blasts, which are published annually in the Hungarian Seismoacoustic Bulletin (HSAB).

Our research aims to model the effect of azimuth deviation due to cross-winds and to investigate its impact on the location of mine explosions in Hungary and neighbouring countries, using data from the Piszkéstető infrasound station (PSZI). 

Using seismic data to determine the dates and locations of the mine explosions, we modeled the resulting infrasound waves using ray tracing. The resulting ground intercepts were used to determine the azimuths of the rays closest to PSZI. With the modeled azimuths of these events, we re-determined their locations using the iLoc single-event location algorithm, which were then compared with the detected azimuths and locations determined without an infrasound phase.

The difference between the detected and modeled azimuth values is less than 5º in most cases, but there were also larger values of around 10º. The differences between locations with and without an infrasound phase were the largest in these cases, and in many instances, the calculation using modeled azimuths was more accurate than the detected ones.

Overall, our research provides a basis for incorporating ray tracing into seismo-acoustic positioning to improve the accuracy of HSAB’s event locations. The method still has some shortcomings, especially when the proximity of the mines to PSZI means no suitable ground intersection point is calculated.