Geological, Geophysical and Seismological Investigations for Siting of Seismic Stations in Minna and Abakaliki, Nigeria for Data Reliability

摘要

The goal of this study is to adopt international standard criteria to carefully select sites to host seismic stations in Minna and Abakaliki, Nigeria, that can give reliable seismic data with high network detectability, monitor local seismicity and record local events with improved accuracy. By this, mistakes made during the construction of existing stations in Nigeria would be avoided systematically. To achieve these therefore, detailed field assessments were carried out to select most suitable site amongst the four potentials sites earlier proposed to host the sensitive seismic equipment for each area. These steps were later followed with detailed geological, geophysical and seismological investigations to ascertain the rock types at the sites; determine the depth of the bedrock where the sensor would be placed; and evaluate the signal to noise ratios and sources of possible noise to the pre-selected sites. Results from the various investigations have helped a team of seismologists, geologists, geophysicists and GIS experts drawn from the Centre for Geodesy and Geodynamics (CGG), Federal Ministry of Science and Technology and the National Emergency Management Agency (NEMA), to select most reliable sites for seismic stations in Minna and Abakaliki. As this is the first time these kind of investigations have been undertaken to select a site for seismic equipment in Nigeria, it is expected this study would set standard practices for future site selection for sensitive equipment in Nigeria and in the sub-region.