Identification of Geothermal Reservoirs in South Cameroon from a Combined Landsat 8 and AMT Data

Piameu Kwagag Joel,Njandjock Nouck Philippe,Ngatchou Evariste,Kue Petou Rokis Malquaire,Owona Angue Marie Louise-Clotilde,Njingti Nfor,Salvatore Gambino

doi:10.1155/2022/1324766

Abstract

This geothermal source prospecting work is carried out in order to respond to the energy deficit affecting the populations of South Cameroon in particular. The study combines audio-magnetotelluric (AMT) and Landsat 8 data for the geolocation of reservoirs, as well as the geological and tectonic information. The processing of these data defined 5 profiles and led to two-dimensional models of resistivity sections for each profile. The interpretation of the data identified a highly conductive zone with a resistivity ranged 1–10 Ω·m at an estimated depth of 1200 m in the locality of Menve’ele. The Landsat 8 data collected in this area during the same period enabled the elaboration of temperature and lineament anomaly maps of the study area. High-temperature areas with high lineament predominance correlate better with areas of low resistivity. For example, Menve’ele (A1) has a surface temperature range of 20°C–30°C and a high density of lineaments. By correlating these results with those provided by previous authors, the Menve’ele locality may be the target of a potential geothermal reservoir. A 3D resistivity model is built to better understand the variations of resistivity and their depths. The geological and tectonic information of the region confirm the tectonic origin of the faults and lineaments as well as the predominance of metamorphic and sedimentary formations.

Highlights

Surface hydrothermal events are often the first indications of the possible presence of high-enthalpy geothermal energy reservoirs, and it is usually necessary to refer to geoscience to confirm their existence, characteristics, and location at depth
The pseudosection shows the resistivity variations along a vertical section. It allows to highlight the areas of lateral discontinuities [34] which appear with a strong horizontal resistivity gradient and contrast with tabular areas where the isoresistivity lines are horizontal
This good correlation of the information obtained from this lineament map with that observed in the field led to the conclusion that the satellite images were collected with a good spatial resolution and a good accuracy

Summary

Introduction

Surface hydrothermal events are often the first indications of the possible presence of high-enthalpy geothermal energy reservoirs, and it is usually necessary to refer to geoscience to confirm their existence, characteristics, and location at depth. The study area is located in Southern Cameroon between parallels 2°20′N-3°20′N of North Latitude and meridians 9.8°E-10.8°E of East Longitude and covers an area of about 111 km (Figure 1). In recent decades, it has shown slight earthquake tremors and active extensional tectonics, which has led to an interest in seismic studies. It has shown slight earthquake tremors and active extensional tectonics, which has led to an interest in seismic studies These volcanic areas are a good indicator of the presence of a geothermal reservoir [2, 3]. Based on seismic data obtained between February 1987 and May 1989 along the volcanic line of Cameroon in its Southwestern continental part, N

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