Study of earthquake waveforms from a new deployment of seismographic stations in northern Iraq


Omar Qadir Ahmed, Bakhtiar Qadir Aziz

Faculty of Science and Science Education, University of Sulaimani  



Abstract
This study is to investigate four different body wave phases from events recorded by eight modern broad-band seismographic stations (NISN) installed in northeastern Iraq. From this network of stations which is distributed in Kurdistan region, a three-component digital data obtained that have been recorded continuously at a rate of 100 sps. The analyses include identifying the P- and S-wave phases from different azimuths and locating the events. The processed local and regional earthquakes which have been recorded in the studied area were in the close proximity to the northeastern border of the Arabian plate and occurred over a period between (2010-2012). In this study, the hypocentral depths are derived from the picked arrival times of P/Pg/Pn, S/Sg and Sn phases and a map was drawn which depicts the epicentral distances for the analyzed waveforms. Furthermore, the source magnitude has been calculated from the amplitude of the wave energy. The resulting events distribution reveals a distinct picture of the interaction between seismicity and seismotectonics of the region. The highest seismicity rate seems to be confined to the exceedingly active northern section of the Zagros thrust zone. 

Keywords: Body waves, amplitude, broadband filter, detection and travel-time. 

REFERENCES 
1-P. E. Green, E.J. Kelly and M. J. Levin (2007): A comparison of seismic array processing methods. Geophysc. Journal Intern. Vol.11, Issue 1. 
2-Stein, S. and M. Wysession (2004): An introduction to seismology, earthquakes, and earth structure. Blackwell Publishing, Oxford. P 507.  
3-Aki, K., and Richards, P. G. (2002). Quantitative seismology. Second Edition, ISBN 0-935702-96-2, University Science Books, xvii + 700 pp. 4-Al-Amri, A. M. (1999): The crustal and upper mantle structure of the interior Arabian platform. Geophys. Journal Int., Vol. 136, p421-430. 
5-Alsinawi, Sahil A & Ghalib, Hafidh A.A. (1975): Historical Seismicity of Iraq.  Bull. Seism. Soc. Amer. Vol. 65, No. 5, PP 541-547.  
6-Al-Sinawi, S. A. (2002): Seismicity, seismotectonics, crustal structure and attenuation data on Iraq. The RELEMR meeting, Antakya, Turkey.  
7-Justin L.Rubinstein and Gregory C. Beroza(2007): Full waveform earthquake location. Journal of Geophys. Research, Vol. 112, B05303, 14 PP.,  
8-Lay T. and T. C. Wallance (1995): Modern global seismology. Academic Press, San Diego. USA, P 521. 
9-Schweitzer, J. (2001): An enhanced routine to locate seismic events. Pure and Appl. Geophys., 158,227-289.  
10-Dziewonski, A. M. and D.L. Anderson (1981): Preliminary reference Earth model. Phys. of Earth and Planet. Int., 25, p. 297-356.