EVALUATION OF GEOTHERMAL ENERGY RESOURCE POTENTIAL IN NORTHEASTERN NIGERIA USING SPECTRAL ANALYSIS OF AEROMAGNETIC DATA

Abstract

Nigeria, despite its continued population growth, does not generate enough power for the country's overall usage. The need for renewable and alternative sources of energy necessitates the need for this research work. The spectral analysis of aeromagnetic data was carried out with the purpose of evaluating geothermal energy resource potential in northeastern Nigeria. The study area is bounded by latitudes 9°30¢00¢¢ N – 14°0¢00¢¢ N and longitudes 9°0¢00¢¢ E – 14°30¢00¢¢ E. Separation of regional and residual was carried out on the total magnetic field intensity (TMI) using the fitting method of order one. For the spectral analysis, a radial power spectrum was applied to the residual data, which was divided into eighty-five (85) square blocks (each block representing each sheet), and each block was analyzed by plotting the log of the power spectrum against the wavenumber to obtain depths to the top ( ) and centroid ( ) of the magnetic anomalous body (source). These depths were used to evaluate the Curie-point depth (CPD), geothermal gradient (GTG), and near-surface heat flow (HF) in the study area. The results revealed that the values of curie point depth ( ) range from 10.28 km to 50.61 km with a mean of 34.02 km, geothermal gradient values range from 11.45  to 56.41  with a mean of 18.14  and heat flow values range from 28.65 ) to 141.03 m  with a mean value of 45.36 . The heat flow has its maximum values around the southwestern portion of the study area. This portion and the entire study area with low values of CPD and high values of heat flow might probably be good geothermal sources and thereby further recommended for detailed geothermal exploration.