The article presents the results of identifying correlation relationships between magnitudes of different types, calculated in international and regional seismological centers. An increase in the number of seismic stations in the Arctic in the 21st century and corresponding increase in the number of recorded earthquakes (due to a decrease in the threshold recording magnitude) has made it possible to identify quantitative relationships between magnitudes based on large samplings of earthquakes and in a wide range of magnitudes. From International Seismological Center data for 1995-2020, we obtained 30 ratios between magnitudes of different types, calculated at different seismological centers, in particular, magnitudes ranging from m(b) and M-S 2.6 and M-L = 0.8. The identified relationships will make it possible to compile an aggregated unified catalog of earthquakes for certain regions of the Arctic, which is necessary, primarily, for assessing the seismic hazard of certain areas, as well as studying low-magnitude earthquakes and clusters and swarms of such quakes.