[1] Aftershocks follow a well‐defined spatial decay pattern in the intermediate field. Here I investigate the same pattern for foreshocks. Foreshock linear density decays as r over distances r of 0.1–30 km for 15 minutes before magnitude 3–4 mainshocks. This trend is the same as that of the aftershocks within the error of the measurement. This consistency of spatial decay can be explained by th...

A measure of the correlation between two earthquakes is used to link events to their aftershocks, generating a growing network structure. In this framework one can quantify whether an aftershock is close or far, from main shocks of all magnitudes. We find that simple network motifs involving links to far aftershocks appear frequently before the three biggest earthquakes of the last 16 years in ...

Many real-life networks can be modelled by stochastic processes with a spatial embedding. In such processes, the link probability decreases with distance. Using the theory of graph limits, we show how to recognize graph sequences produced by random graph processes with a linear embedding (a natural embedding into R). We define an operator Γ which applies to graph limits, which assumes the value...

This work reviews some results obtained already for the variations of the seismicity parameters b and p in different seismogenic and tectonic regions in Japan. We bring as well new evidence that the time and space changes in seismicity parameters are correlating well with the crustal structure and/or some parameters of the earthquake process. In the first part of the paper we show that several ...