Complex networks and the b-value relationship using the degree probability distribution: the case of three mega-earthquakes in Chile in the last decade

Abstract

Studies from complex networks have increased in recent years, and different applications have been utilized in geophysics. Seismicity represents a complex and dynamic system that has open questions related to earthquake occurrence. In this work, we carry out an analysis to understand the physical interpretation of two metrics of complex systems: the slope of the probability distribution of connectivity (gamma) and the betweenness centrality (BC). To conduct this study, we use seismic datasets recorded from three large earthquakes that occurred in Chile: the M(w)8.2 Iquique earthquake (2014), the M(w)8.4 Illapel earthquake (2015) and the M(w)8.8 Cauquenes earthquake (2010). We find a linear relationship between the b-value and the gamma value, with an interesting finding about the ratio between the b-value and gamma that gives a value of similar to 0.4. We also explore a possible physical meaning of the BC. As a first result, we find that the behaviour of this metric is not the same for the three large earthquakes, and it seems that this metric is not related to the b -value and coupling of the zone. We present the first results about the physical meaning of metrics from complex networks in seismicity. These first results are promising, and we hope to be able to carry out further analyses to understand the physics that these complex network parameters represent in a seismic system.