Heat flow and continental breakup: The Gulf of Elat (Aqaba)

Abstract

Heat flow measurements were made at five sites in the major basins of the Gulf of Elat (Aqaba), northern Red Sea. The gulf is located at the southern portion of the Dead Sea rift, which is a transform plate boundary. Vertical temperature gradients were measured with a probe which allows multiple penetration of the bottom during a single deployment, and thermal conductivities were determined by needle probe measurements on sediment cores. A mean heat flux of about 80 mWm−2 was found, and the values tend to increase from north to south. This latitudinal gradient corresponds to the general trend of gradual thinning of the continental crust of the gulf toward the Red Sea, where oceanic crust exists. The heat flow data, together with other geophysical data, are consistent with a propagation of rifting from the Red Sea northward along the Dead Sea rift, where the fractures are primarily shear. The gulf forms a transition between these two tectonic regimes, extensional Red Sea to the south and transform Dead Sea to the north.