HOMOGENEOUS MAGNITUDE SYSTEM WITH UNIFIED LEVEL FOR USAGE IN SEISMOLOGICAL PRACTICE

A homogeneous magnitude system (HMS) for determining comparable magnitudes of shallow earthquakes was established and tested on the basis of several thousands of observations of 32 Eurasian seismic stations for seven different wave types. The magnitude level of the HMS was fixed by the level of LH-wave magnitudes, which allows us to maintain the continuity of the HMS magnitudes with the routinely used surface wave magnitudes. The comparable level for magnitudes determined from other wave types was obtained by shifting all the magnitude scales to a common point at magnitude 6.75. The compatible calibrating functions are tabulated and recommended for testing in seismological practice.