Estimation of radiogenic heat production of the Adamawa region in Cameroon, Central Africa: an insight from spectral analysis of EMAG2 data

Geothermal energy is one of the solutions for energy issues in sub-Saharan countries such as Cameroon, while addressing the environmental issues of the Paris Agreement. This study provides a new database on heat flow, radiogenic heat production, and geothermal gradient for the Adamawa region in Central Cameroon, which suffers from energy issues. This database serves as a framework for future research on geothermal energy for this region. Specifically, the study uses spectral analysis of Grid Earth Magnetic Anomaly (EMAG2) to present an overview of the thermal structure anomaly from surface events related to the volcanic activity of the Adamawa region. This spectral method has been applied to the magnetic data from the equator. The magnetic map was obtained from the correction of the reduction at the equator divided into 17 overlapping blocks of 100 × 100 km in order to estimate the Curie point depth (CPD), which allowed us to obtain the values for the heat flow, radiogenic estimate, and P-wave velocity ( V p ). The depths vary from 16 and 41 km, while the heat flow varies from 91 to 98 mW m -2 . The Adamawa region is characterized by low Curie point depth values due to the identified geothermal gradient regime that reveal the influence of near-surface mantle convection. In this region, the radiogenic heat production ranges from 0.024 to 0.303 μW m -3 , with the low radiogenic heat values being related to heat flow. The seismo-tectonic activity in the region only involves high-intensity earthquakes produced along the Cameroon Volcanic Line as a subduction zone more precisely in the locality of Woulndé. The heat flow observed from the data may suggest the existence of an anomalous heat source in the crust due to radiogenic heat results.