Morisita-based space-clustering analysis of Swiss seismicity

• The mm-Morisita index analysis was applied to the Swiss seismicity.
• The whole catalog is more spatially clusterized than the aftershock-depleted one.
• The spatial clustering increases with the increase of the threshold magnitude.
• The whole and aftershock-depleted catalogs show similar multifractal behavior.

The mm-Morisita index analysis was applied to the Swiss seismicity to investigate its space clustering properties. The analysis of the whole and aftershock depleted catalogs has revealed that the whole catalog is more spatially clusterized than the depleted one and that the clustering increases with the increase of the threshold magnitude. Furthermore, the multifractality degree of both catalogs is approximately the same. Our findings evidence the role played by the aftershocks in contributing to the increase of the spatial clustering of the earthquakes and that the spatial heterogeneity of seismicity is controlled by the main faults that produce the most independent events.