| Title | EMPIRICAL RELATIONS OF SEISMIC MOMENT AND EARTHQUAKE MOMENT MAGNITUDE TO EARTHQUAKE LOCAL MAGNITUDE FOR THE VARDAR AND WEST MACEDONIA SEISMIC ZONES |
| Author/s | Vera Čejkovska |
| Citation | V. Čejkovska, "EMPIRICAL RELATIONS OF SEISMIC MOMENT AND EARTHQUAKE MOMENT MAGNITUDE TO EARTHQUAKE LOCAL MAGNITUDE FOR THE VARDAR AND WEST MACEDONIA SEISMIC ZONES", Contributions, Sec. Math. Tech. Sci., MASA, ISSN 0351–3246, Vol. 27-28, no.1-2, (2006-2007), pp.93-115. |
| Abstract | Seismic moments (M0) of 79 earthquakes which ed in the Vardar and West Macedonia seismic zones on the territory of the Republic of Macedonia and neighbouring regions within the period 1992–2002 were obtained by inversion of the amplitude spectra of the vertical components of the short-period shear Sg and Lg surface waves, digitally recorded on the electromagnetic short-period SS-1 and wide-range WR-1 Kinemetrics seismometers at the stations in Skopje (SKO), Ohrid (OHR), Valandovo (VAY), Bitola (BIA) and Kriva Palanka (KPJ). The inversion was done on the Brune dislocation source model and a proper model of the medium. The data used included earthquake local magnitudes (ML) between 1.5 and 5.2, for the Vardar seismic zone, and between 1.4 and 5.2, for the West Macedonia seismic zone. Moment magnitudes (MW) of the earthquakes were calculated using the Kanamori formula. Empirical M0 – ML and MW – ML relations were obtained, the first of the kind for seismic zones in the territory of the Republic of Macedonia. The results also appointed to a differentiation between classes of small and middle-sized earthquakes at ML = 5.2 and to a change in the scaling law of the small earthquakes at ML ≈ 3.0 – 3.5 or M0 ≈ 6·1013 – 1.5·1014 N·m. |
| Keywords | seismic source parameters; seismic moment; earthquake moment magnitude; empirical relations |
