Local magnitude scale for earthquakes in Turkey
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Based on the earthquake event data accumulated by the Turkish National Seismic Network between 2007 and 2013, the local magnitude (Richter, Ml) scale is calibrated for Turkey and the close neighborhood. A total of 137 earthquakes (Mw > 3.5) are used for the Ml inversion for the whole country. Three Ml scales, whole country, East, and West Turkey, are developed, and the scales also include the station correction terms. Since the scales for the two parts of the country are very similar, it is concluded that a single Ml scale is suitable for the whole country. Available data indicate the new scale to suffer from saturation beyond magnitude 6.5. For this data set, the horizontal amplitudes are on average larger than vertical amplitudes by a factor of 1.8. The recommendation made is to measure Ml amplitudes on the vertical channels and then add the logarithm scale factor to have a measure of maximum amplitude on the horizontal. The new Ml is compared to Mw from EMSC, and there is almost a 1:1 relationship, indicating that the new scale gives reliable magnitudes for Turkey.
KeywordsLocal (Richter) magnitude scale Magnitude calibration Wood-Anderson seismogram Horizontal vs vertical amplitude Geometrical spreading Seismic attenuation
This research has been conducted as part of the project UDAP-Ç-12-15 titled “Calibration and Implementation of Earthquake Magnitude Scales for Turkish National Seismic Network,” National Earthquake Research Program, AFAD, Turkey, 2013.
- Alsaker A, Kvamme LB, Hansen RA, Dahle A, Bungum H (1991) The ML scale in Norway. Bull Seism Soc Am 81(2):379–398Google Scholar
- Bakun WH, Joyner WB (1984) The Ml scale in central California. Bull Seism Soc Am 74:1827–1843Google Scholar
- Geofon-Gitews Development Group (2009). Seiscomp 3 Manual, PotsdamGoogle Scholar
- Havskov J, Ottemöller L (2010) Routine data processing in earthquake seismology. Springer, The Netherlands, p 347Google Scholar
- Herrmann RB (1975) The use of duration as a measure of seismic moment and magnitude. Bull Seismol Soc Am 65(4):899–913Google Scholar
- Hutton LK, Boore DM (1987) The Ml scale in Southern California. Bull Seism Soc Am 77:2074–2094Google Scholar
- Kadirioğlu, FT, Kartal RF, Kılıç T, Kalafat D, Duman TY, Özalp S, Emre Ö (2014) An Improved Earthquake Catalogue (M ≥ 4.0) For Turkey And Near Surrounding (1900–2012). Proceedings of 2nd European Conference on Earthquake Engineering and Seismology, İstanbul Aug. 25–29 2014, Page:411–422Google Scholar
- Kim W-Y (1998) The ML scale in Eastern North America. Bull Seism Soc Am 88:935–951Google Scholar
- Kiratzi AA, Papazachos BC (1984) Magnitude scales for earthquakes in Greece. Bull Seismol Soc Am 74(3):969–985Google Scholar
- LahrJ (1999) HYPOELLIPSE: A Computer Program for Determining Local Earthquake Hypocentral Parameters, Magnitude, and First-Motion Pattern, Version1.0, www.jclahr.com/science/software/magnitude/ml/index.html, last accessed, Novenber 16 2015.
- Menke W (1989) Geophysical Data Analysis: Discrete Inverse Theory. Academic Press, San Diego, CaliforniaGoogle Scholar
- Ottemöller L, Voss P, Havskov J (2013) Seisan Earthquake Analysis Software For Windows, Solaris, Linux And Macosx, Software Manual V.9.0Google Scholar
- Polat O, Gök E, Yılmaz D (2008) Earthquake Hazard of the Aegean Extension Region (West Turkey), Turkish J. Earth Sci 17:593.614Google Scholar
- Press WH, Flannery BP, Teukolsky SA, Vetterling WT (1986) Numerical Receips in Fortran. Cambridge University Press, New York, 702 pGoogle Scholar
- Richter CF (1935) An instrumental earthquake magnitude scale. Bull Seism Soc Am 25:1–32Google Scholar
- Soysal H, Sipahioğlu S, Kolçak D, Altınok Y (1981) Historical Earthquake Catalogue of Turkey and Surrounding Area (2100 B.C. – 1900 A.D.). Technical Report, TUBITAK, No. TBAG-341Google Scholar
- Tezel T, Yanık K (2013) Improvement in Mwp Magnitude Determinations and Applications to Earthquakes in Turkey. SRL 84(6):991–996Google Scholar