Vol. 57, No. 1, 2022

A. N. S. Feumoe, M. P. Mouzong and E. H. Ngatchou

Vol. 57, No. 1, 2022

Abstract

Geothermal energy resources of the northern part of Congo Craton boundary in Cameroon are highlighted by 3-D geophysical inversion-modeling and intrusion estimation using gravity data. Determination of the magnitude maxima of (1) tilt derivative gravity allowed map to be produced showing various lines of fractures interpreted as the preferential paths for circulation of geothermal energy resources up flow to the surface, and (2) the total horizontal derivative give an overview of the possible deep geological setting in the area, which are acting as the source of geothermal potential. We find that these structures (fractures and igneous intrusion) are associated to long-wavelength anomalies, suggesting that its should be connected with large-scale structural deformation due to the collision between Congo Craton (CC) and Pan-African belt or Mobile zone (MZ). Interpretation of 3-D density models derived from the inversion of gravity data shows the presence of igneous intrusion within the faults with high density, probably granulitic rocks put in place during the Pan-African belt reactivation. The distribution of high density constitutes the geothermal potential energy resources of the studied area.

Abstract

Knudsen (1900) derived relations for water and salt when baroclinic water exchange dominates in a semi-enclosed basin. Here, are the corresponding relations for barotropic water exchange developed. With these relations at hand, the net volume and net salt exchange can be found as averages over a certain time, say a week, month, or year. These relations are applied to the barotropic water exchange in the Sound strait connecting the Baltic Sea with the Kattegat. The study covers the years 1977 to 2018. Volume in- and outflows are characterized by being of the same order of magnitude, whereas the average time for inflow and outflow is close to 35 % and 65 %, respectively. The average net volume flow is close to 50 % of the average runoff input to the Baltic Sea, suggesting the other 50 % of the runoff input is leaving through the Belt Sea strait. The seasonal net volume flow through the Belt Sea strait is estimated by closing the Baltic Sea water budget. During summer, the Sound and the Belt Sea straits show different responses to changes in runoff and Baltic Sea volume. The net volume flow through the Belt Sea strait even change sign being directed inwards during June and July on average.