A homogenous moment magnitude and local magnitude scaling relation for earthquakes in Egypt

Abstract

ABSTRACT In this work, we publish a moment-local magnitude scale catalogue for the Egyptian National Seismic Network (ENSN) since 1997 to 2019 as necessary for the study of seismicity and seismic hazard estimation. Every year, the ENSN publish an annual bulletin of local and regional earthquakes recorded by the network with local magnitude (Ml) scale. The ENSN was recorded more than 36,730 approximately for local events since 1997. In this work, the Moment magnitudes (Mw) are computed for small earthquakes using a spectral analysis method, while the Moment magnitudes of moderate and large earthquakes are obtained using a complete waveform inversion and moment tensor techniques. An empirical relationship between moment magnitude (Mw) and local magnitude (Ml) of the earthquakes are developed using a linear regression. The Mw–Ml relationship used in this study was as follows: Mw = 0.69 Ml + 0.58 for earthquakes with magnitude ≤3 Mw = 0.95 Ml – 0.15 for earthquakes with magnitude 3< ML≤6 The ENSN local magnitude (Ml) catalogue was converted to a moment magnitude (Mw) catalogue and attached as a supplementary material with this article for use by the researchers and authors in tectonic studies and seismic hazard evaluation of the region.