Greener Journal of Physical Sciences

Open Access

Afegbua and Ezomo

Greener Journal of  Physical Sciences  Vol. 3 (2), pp. 048-057, February 2013.

ISSN: 2276-7851 © 2011 Greener Journals

Research Paper

Manuscript Number: 011613383

 

Investigating Seismic Noise from Horizontal Components of the Nigerian Seismic Network Stations

 

1Kadiri Umar Afegbua and 2F.O. Ezomo

 

1*Earthquake Seismology Dept., Centre for Geodesy and Geodynamics, P.M.B. 11, Toro, Bauchi State, Nigeria.

2Department of Physics, Faculty of Physical Sciences, University of Benin, Ugbowo, Benin City, Edo State, Nigeria.

 

1*Corresponding Author’s Email: Email: umakad @ yahoo.com, Tel: +2348037122784


Abstract:

Seismic noise on the horizontal components of the Nigerian National Network of Seismographic Stations (NNNSS), comprising Awka, Ife, Nsukka, Kaduna and Toro, has been investigated using 2012 data. It was observed that the noise levels were high compared with the globally accepted Peterson noise curves for estimating station’s performance, which may likely be due to the tilt effects and other environmental and probably human factors too. For instance, in spite of the geologic and geographic locations that would have guaranteed low noise, high noise levels were observed at Toro and Kaduna stations, due to anthropogenic and self-noise from wrong instrument calibration and tilt effects, while Ife station experienced the most pronounced tilt effect. Although, geologic foundation for each site was established before siting of the five operational stations, the observed high noise levels on the horizontal component may have contributed to reducing the quality of data from the stations. This study therefore was intended to quantify the amount of noise present on the horizontal components of the stations and compare with Peterson New Global High Noise Model and New Global Low Noise Model curves, with a view to adopting better practices on installation techniques.
 
Keywords: NNNSS, tilt effect, noise spectral, horizontal component seismic traces.

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