Afegbua and Ezomo
Greener Journal of Physical Sciences Vol. 3 (2), pp. 048-057, February 2013.
ISSN: 2276-7851 © 2011 Greener Journals
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
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.