Determining the Success of Strong Motion Records in Calculating P-Wave Moment Magnitude

Abstract

Earthquake early warning systems have high importance and improving continuously using different analysing techniques. The system depends on calculating a magnitude in a short time with as high accuracy as possible. Large earthquakes that have tsunami potential occurred and will be occurred especially in the Mediterranean and Aegean Seas Turkey has settlements along these coastlines. In practice, weak-motion (velocity) records are generally used to determine the magnitude, but these seismic records have a disadvantage: a clipping problem around the epicentre. Up to now, there is not much work on the study of the strong-motion (acceleration) records to calculate the magnitude of an earthquake in a short time with high accuracy. This study focused on calculating the P-wave moment magnitude using P-wave body waves recorded at strong motion seismic stations caused by possible tsunami source region earthquakes. For that reason, we used three earthquakes that have a magnitude larger than 6.0 Mw. The difference between the Global Centroid Moment Tensor (GCMT) moment magnitude is about 0.2 m.u. which is acceptable considering an early warning purpose.

Keywords

• Early warning
• Strong motion
• The Mediterranean
• Turkey
• Earthquake

References

1. Fokaefs A, Papadopoulos G. Historical earthquakes, and tsunami sources in Eastern Mediterranean Sea. Geophys Res Abs 2005; 7:00732.
2. Yolsal S, Taymaz T, Yalciner A.C. Understanding tsunamis, potential source regions and tsunami-prone mechanisms in the Eastern Mediterranean. Geol. Soc. London Spec Publ 2007; 291:201-230.
3. Ozel NM, Necmioglu O, Yalciner AC, Kalafat D, Erdik M. Tsunami hazard in the Eastern Mediterranean and its connected seas: Toward a Tsunami warning center in Turkey. Soil dyn Earthq Eng 2011; 31:598-610.
4. Tsuboi S, Abe K, Takano K, Yamanaka Y. Rapid determination of Mw from broadband P waveforms. Bul Seismol Soc Am 1995; 83:606–613.
5. Tsuboi S, Whitmore PM, Sokolowski TJ. Application of Mwp to deep and teleseismic earthquakes. Bul Seismol Soc Am 1999; 89:1345–1351.
6. Tsuboi S. Application of Mwp to tsunami earthquake. Geophys Res Lett. 2000; 27:3105–3108.
7. Whitmore PM, Tsuboi S, Hirshorn B, Sokolowski TJ. Magnitude dependent correction for Mwp. Sci Tsunami Hazards 2002; 20:187–192.
8. Hirshorn B, Weinstein S, Tsuboi S. On the application of Mwp in the near field and the March 11, 2011 Tohoku earthquake. Pure Appl Geopghys 2013; 170:975-991.

9. Tezel T, Yanik K. Improvement in Mwp magnitude determinations and applications to earthquakes in Turkey. Seismol Res Let 2013; 84:91–96.
10. Tezel T. Application of P-wave magnitude to earthquakes for tsunami early warning in and around South- Western Turkey. Studio Geophys Geod 2015; 59.https://doi.org/ 10.1007/s11200-014-0825-2
11. Tezel T. Adaptation of P-wave moment magnitude of Turkey’s earthquakes for early warning purpose. Journal of Seismology 2022; https://doi.org/10.1007/s10950-021-10069-2
12. Kanamori H. The energy release in great earthquakes. J Geophys Res 1977; 82:2981–2987.
13. Hanks T, Kanamori H. A moment magnitude scale. J Geophys Res 1979; 84:2348–2350. [14] Goldstein P, Dodge D, Firpo M, Miner L. SAC200: Signal processing and analysis tools for seismologists and engineers. In: Lee W.H.K., Kanamori H., Jenings P.C. and Kisslinger C.(Eds), International Handbook of Earthquake and Engineering Seismology. International Geophysics 2203; 81:PartB,1613−1614.
14. Wessel P, Smith WHF. New, improved version of Generic Mapping Tools released. EOS Trans AGU 1998; 79:579.