Accurate local magnitude prediction for small to moderate earthquakes using rapid calculations of P-wave dominant period
This study examines mechanisms of rapid and accurate determination of local magnitude Mpd for small to moderate events that occurred in West Sulawesi and Central Sulawesi using direct procedures and calculations of the dominant period Td of P-waveforms. Secondary data were collected from Webdc3, comprising earthquake magnitudes in the regions of interest during 2008-2015 measured in MW. The study focuses on earthquake size estimates for local events as a parameter through simple evaluation of a linear equation relating Td to MW. For all the events considered, empirical formulas derived from the random data for estimating the size are, respectively, Mpd = (Td + 6.6799)/1.5199 for West Sulawesi and Mpd = (Td + 3.3648)/0.8464 for Central Sulawesi. Each was used to recalculate events in the two regions. The results were compared to the reference provided by the Global CMT catalog. The results are consistent with the reference having a standard deviation of up to 0.2, showing evidence of no significant difference in magnitude determination between the method proposed in the current study and that of the Global CMT. This suggests that rapid and accurate magnitude determination is best predicted by the empirical formula developed for each region in this study for future use of disaster risk reduction program.
Satriano, C., Wu, Y. M., Zollo, A., & Kanamori, H. (2011). Earthquake early warning: concepts, methods, and physical grounds. Soil Dynamics and Earthquake Engineering, 31(2), 106–118. https://doi.org/10.1016/j.soildyn.2010.07.007
Satake, K. (2014). Advances in earthquake and tsunami sciences and disaster risk reduction since the 2004 Indian ocean tsunami. Geoscience Letters, 1, 1–13.
McCalpin, J. P. (2010). Appendix 1: Earthquake Magnitude Scales. GEO-HAZ Consulting Inc. Crestone, Colorado 81131.
Lomax, A., & Michelini, A. (2011). Tsunami early warning using earthquake rupture duration and P-wave dominant period: the importance of length and depth of faulting. Geophysical Journal International, 185, 283–291.
Lomax, A., & Michelini, A. (2012). Tsunami early warning within five minutes. Pure and Applied Geophysics, 170( 9–10), 1385–1395. https://doi.org/10.1007/s00024-012-0512-6
Madlazim (2013). Assessment of tsunami generation potential through rapid analysis of seismic parameters - case study: comparison of the Sumatra earthquakes of 6 April and 25 October 2010. Science of Tsunami Hazards, 32, 29–38.
Madlazim, Prastowo, T., & Hardy, T. (2015). Validation of Joko Tingkir software using tsunami importance. Science of Tsunami Hazards, 34, 189–198.
Madlazim, & Prastowo, T. (2016). Evaluation of earthquake parameters used in the Indonesian tsunami early warning system. Earthquake Science, 29, 27–33.
Baeda, A. Y. (2011). Seismic and tsunami hazard potential in Sulawesi Island Indonesia. Journal of International Development and Cooperation, 17, 17–30.
The Germany Government, Geoforschungs Zentrum (GFZ), Helmholtz-Zentrum Postdam. (2016). Retrieved from http://eida.gfz-potsdam.de/webdc3/.
The Global Centroid-Moment-Tensor web page. (2016). Retrieved from http://www.globalcmt.org/.
Anthony A. Lomax’s home page. (2016). Retrieved from http://alomax.free.fr/seisgram/SeisGram2K.html.