Abstract

We present a fractality study performed in southern Norway (3°?12° E, 57°?64° N) using 12,892 low-magnitude intraplate seismic events. The earthquakes were recorded by the Norwegian National Seismic Network (NNSN) between the years 1980–2021. We calculated the multifractal spectrum dimension considering its temporal evolution and analyzing possible effects of the magnitude of completeness, Mc, on the results. We computed the multifractal spectrum dimension in data windows in order to follow the changes of the parameter Dq in time. The nonlinear behavior of this earthquake system has as an evidence how the temporal fractal dimension values vary approximately between Dq=0.3 and Dq=1.9 for 0?q?10 for different fractal windows. The capacity and correlation dimensions were equal to (D0,D2)=(2.06±0.06,1.72±0.05) and (D0,D2)=(2.13±0.001,D2=1.70±0.05) for the catalog with and without Mc, respectively. The last suggests the existence of seismic sources related to linear fracturing and a slight seismic clustering, and confirms the effect of 2D seismogenic faults in the seismicity nucleation. As a novel contribution, we found a strong mathematical similarity between the fractal dimension D10 and the earthquake magnitudes, which may be used as a new tool for earthquake forecasting in low-magnitude intraplate environments. We express this relationship through a linear equation valid for the South Norwegian intraplate seismicity. The results were, using the same procedure, compared with an intraplate seismic catalog from the Iquique area, located in northern Chile. © 2022 Elsevier Ltd