Visibility graph analysis of 2002-2011 Pannonian seismicity

The Visibility Graph (VG) properties of the seismic sequence which occurred in Pannonia from 2002 to 2011 have been put in a relationship with the seismic parameter b-value derived from the Gutenberg-Richter law; this law, which is the frequency-magnitude distribution, represents the main characteristic of a seismic sequence. It is found that between the b-value of the Pannonian seismicity and the slope of the least square fitting line of the k-M plot (which is the relationship between the magnitude M of each event and its connectivity degree k) there exists a close relationship. The relationship is valid for two depth classes of events, shallow (depth less than 40 km) and deep (depth larger than 70 km), for which different mechanisms of earthquake generation exist. These results confirm similar findings already obtained for the seismicity in different areas of Mexico (Telesca et al., 2013), suggesting the existence of a universal law.