Indications of an Underground River Beneath the Amazon River: Inferences From Results of Geothermal Studies

Analysis of geothermal data for the basin systems of the Amazon region reveals non-linear features in the subsurface temperature distributions. Results of numerical simulations indicate that such features cannot be attributed to mechanisms other than advective heat transfer, originating from downward fluid flows. Velocities of such fluid flows were calculated using a steady state model of flow through porous media comprising the sedimentary basins. The depth ranges and area extent of such flows indicate the existence of generalized lateral flow in the basin systems of the Amazon region (Acre, Solimões, Amazonas, Marajó e Barreirinhas). The direction flow inferred from the basement topography fo the region is from the western to the eastern parts. Estimates of flow rates indicate that Amazonas basin has highest flow rate while the Marajó basin has the lowest. Overall flow rate is estimated to be in the range of 3900 to 4000m3/s, substantially higher than the maximum flow rate of São Francisco river in eastern Brazil.