Correlation of MLH and mpv by Data of the Network of Seismic Stations of the U.S.S.R.

Summary The problem of maintaining uniform magnitude scales is important in seismology. It is shown that the surface wave magnitudes measured in the Soviet Union (MLH) are in good agreement with those from Pasadena, Berkeley and Palisades, and are considered to be a good continuation of M as used by Gutenberg and Richter in their catalogue. Body wave magnitudes, however, show a systematic difference between USCGS and Russian determinations, the Coast and Geodetic Survey values being significantly lower. Several possible reasons for this are examined and it is concluded that the regular contribution of certain stations (BMO, UBO, TFO and WMO) which consistently report lower magnitudes than most stations is a major cause of the discrepancy.