Between February 16 and April 5, 2019, a series of earthquakes took place around the
village of Somogyszob, Somogy county, Hungary. The mainshock occurred on March 7 with
a local magnitude M-L=4.0 and epicentral intensity of 5 on the EMS scale. The main
event was preceded by four foreshocks and followed by four aftershocks. The largest
foreshock (M-L=2.6) was also felt with maximum intensity of 4 EMS. This earthquake
sequence is the first remarkable one in the region that was recorded by a significant
number of high-quality broadband digital seismographs. We have estimated the hypocenters
of the 9 earthquakes using the hypoDD multiple-event location algorithm. The events
occurred in a tight region around the mainshock at around 13-14 km depth. For the
main event, we obtained an average moment magnitude of M-w=3.75, source radii of r(P)=509
m nd r(S)=400 m, and static stress drops of Delta sigma(P)=1.19x10(6) Pa and Delta
sigma(S)=4.00x10(6) Pa from the analysis of displacement P- and S-wave spectra, respectively.
The resulting spectral source parameters for the investigated events agree well with
the results of earlier research. We have also shown that our recently developed probabilistic
waveform inversion techniques applied in this study are suitable to retrieve the source
mechanism for weak local earthquakes. We have successfully estimated the focal mechanism
for the mainshock, a foreshock and an aftershock. Each earthquake was a thrust faulting
event with a sub-horizontal P-axis pointing towards N-NE, coinciding with the general
trend of the compressional stress field in the epicentral region.
