Abstract

LOPEZ, Caroll  and  OJEDA, German. HEAT FLOW IN THE COLOMBIAN CARIBBEAN FROM THE BOTTOM SIMULATING REFLECTOR (BSR). C.T.F Cienc. Tecnol. Futuro [online]. 2006, vol.3, n.2, pp.29-39. ISSN 0122-5383.

Geothermal heat flow in gas hydrate zones can be determined theoretically from the Bottom-Simulating Reflector. A Bottom-Simulating Reflector (BSR) has been observed in multichannel seismic data from the Caribbean offshore Colombia. This anomalous reflector, known to correspond with the base of the Gas Hydrate Stability Zone (GHSZ), can be used to estimate a range of possible values for the local heat flow using the stability field of gas hydrates and the thermal conductivity of the sediments. The study area extends from northern Guajira in the north to the Gulf of Uraba in the south, covering some 18 000 km². The heat flow was found to be 27,6 ± 4 mW/m² off the coast of Barranquilla, 37,9 ± 3,6 mW/m2 for northern Guajira, 33,2 ± 5,5 mW/m² for the central Guajira and 34,7 ± 9,4 mW/m² for the Cartagena -Gulf of Uraba offshore areas. These results are comparable to heat flow estimates of 30 and 42 mW/m² obtained for the south Caribbean by others using alternate methods. The estimated heat flow is relatively low in relation to other continental margins. The continuous and fast sedimentation rate from the Magdalena River may explain the anomalously low heat flow in the river delta area. The Cartagena-Gulf of Uraba zone evidences the presence of advection heat loss in the accretionary wedge of the South Caribbean deformation front.

Keywords : gas hydrate; bottom simulating reflector (BSR); heat transfer; Caribbean area; Colombia.

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