High heat flow inferred from analysis of high resolution aeromagnetic data of south-western Nigeria

A high heat flow has been inferred from the power spectra analysis of recently acquired high resolution aeromagnetic (HRAM) data of south-western Nigeria. The HRAM data, bounded by latitudes 6.5 degrees N and 9.0 degrees N and longitudes 4.0 degrees E and 6.5 degrees E, were divided into sixteen overlapping blocks of 110 x 110 km and each block analysed to evaluate the depth to bottom of magnetic sources (DBMS). The pieces of DBMS information were subsequently used to estimate ensuing heat flow parameter in the study area. The results revealed DBMS values ranging from 10.48 to 19.87 km while heat flow values range between 72.97 and 138.36 mWm(-2). The results also demonstrate that about 37.5 % of the area is dominated with heat flow greater than 100 mWm(-2). Heat flow in the neighbourhood of 100 mWm(-2) and above is considered anomalous and are likely due to active tectonic activities, therefore it is expected that areas with such anomalous elevated heat-flow be monitored closely.