Abstract
After Cairo Earthquake in 1992 (Ms 5.9), the government established the Egyptian National Seismological Network (ENSN) organized by the National Research Institute of Astronomy and Geophysics (NRIAG) start to work since 1997; NRIAG has a real monitoring of the seismological activity in and around different parts of Egypt. A selected 5000 events from the ENSN annual bulletin in the period 2004–2013 with calculated local magnitude (M L) based on Richter regular formula was used in this study; a duration magnitude was calculated for these events and regressed with M L. Another aim of this study is to develop a regression relation of the calculated body wave magnitude (M b) to the unified moment magnitude (M w) which is the base for homogenization of earthquake catalogue needed for seismic hazard studies. Standard least square regression usually fails to give reliable results when both regressed variables have measurement errors; orthogonal standard regression (OSR) is the most reliable tool used for conversion of observed M b values with the moment magnitude M w. The accuracy of the resulting relations from regression have been checked with another 20 events of the data and shows the advantage of using OSR method to get regressed relation to homogenize any catalogue containing various magnitudes with measurement errors, by their regression with a Mw. The proposed procedure also remains valid in case the magnitudes have measurement errors different from unity.
Similar content being viewed by others
References
Abu El Enean K (1997) A study on the seismotectonics of Egypt in relation to the Mediterranean and Red Sea tectonics. Ph.D. Thesis, Ain Shams Univ., Fac. of Sci., Cairo, Egypt
Aki K, Chouet B (1975) Origin of coda waves: source, attenuation and scattering effects. J Geophys Res 80:3322–3342
Bindi D, Spallarossa D, Eva C, Cattaneo M (2005) Local and duration magnitudes in northwestern Italy, seismic moment versus magnitude relationships. Bull Seismol Soc Am 95(2):592–604
Bisztricsany E (1958) A new method for the determination of the magnitude of earthquakes. Geofiz Kozl 7:69–76
Castellaro S, Bormann P (2007) Performance of different regression procedures on the magnitude con- version problem. Bull Seismol Soc Am 97:1167–1175
Gasperini P (2002) Local magnitude revaluation for recent Italian earthquakes (1981–1996). J Seismol 6:503–524
Gasperini P, Ferrari G (2000) Deriving numerical estimates from descriptive information: the computation of earthquake parameters. Ann Geofis 43(4):729–746
Gutenberg B (1945a) Amplitudes of P, PP, and S and magnitude of shallow earthquakes. Bull Seismol Soc Am 35:57–69
Gutenberg B (1945b) Magnitude determination of deep-focus earthquakes. Bull Seismol Soc Am 35:117–130
Lee WHK, Bennet RE, Meaghu KL (1972) A method of estimating magnitude of local earthquakes from signal duration. U.S. Geological Survey Open File Report, p. 28
Ristau J (2009) Comparison of magnitude estimates for New Zealand earthquakes: moment magnitude, local magnitude, and tele-seismic body-wave magnitude. Bull Seismol Soc Am 99:1841–1852
Solov’ev SL (1965) Seismicity of Sakalin. Bull Earth Res Inst Tokyo Univ 43:95–102
Acknowledgments
Our gratitude is due to all members of the National Research Institute of Astronomy and Geophysics (NRIAG) for valuable cooperation to produce this work as a result of a real scientific cooperation.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Abdel Hafiez, H.E. Magnitude scales regression for Egyptian seismological network. Arab J Geosci 8, 7941–7954 (2015). https://doi.org/10.1007/s12517-015-1807-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12517-015-1807-6