Geophysical Method for Determining Geothermal Source Potential in Parts of the South-West and South-South, Nigeria

Abstract

In order to determine the depths of magnetic sources in the study area, this study offers a thorough evaluation of high-resolution aeromagnetic data using quantitative and qualitative methodologies, including spectral depth analysis, filtering techniques, and statistical analysis. The results show that the centroid depth (Zo) varies between 8.667 km and 20.824 km, while the magnetic source depth to the top (Zt) ranges between 2.173 km and 10.304 km. The Curie point depth map, which ranges from 9.57 km to 29.486 km, shows shallow Curie depths ranging from 9.5 km to 14 km in the eastern part of Edo State. On the other hand, the borders with Ekiti, Osun, Ondo, Kogi, and Delta states show deeper depths ranging from 16 km to 29 km. Geothermal gradient investigation shows values ranging from 19 to 56 °C/km. Geothermal gradients range from 19 to 56 °C/km, with lower values (19–30.34 °C/km) in northern and western Edo and higher values (45–56.34 °C/km) in some municipalities. The towns in eastern Edo showed heat flow levels between 106 and 122 mW/m², whereas the overall range was 48 to 141 mW/m². Northern, western, and southern boundaries, on the other hand, show heat flow rates between 48 and 80 mW/m² that are lower. The results show that eastern Edo State has a lot of untapped geothermal energy potential, especially in cities with strong heat flows and geothermal gradients. We have identified Okada, Auchi, and Ugboku as promising locations for future investigation and resource extraction. Not only does this study add to our understanding of the region's geothermal terrain, but it also promotes the use of renewable energy sources, which might boost the economy and make the area more self-sufficient.