Three brine lakes discovered in the seafloor of the eastern Mediterranean

Abstract

Three lakes of concentrated brine were discovered in the seabed of the Mediterranean Ridge, southwest of Crete in late 1993 and early 1994. These lakes have a distinctive appearance on side‐scan sonar images with no backscattering from the lake surface and enhanced backscattering at their edges (Figure 1). Measurements with conductivity‐temperature‐depth (CTD) and heat flow probe show in one case a near‐isothermal temperature for the lake water and in another thermal layering. The chemistry of the brines varies in each lake and shows that the brines are derived from selective solution of different parts of the Messinian evaporites that lie beneath the seafloor. Flow of seawater through the sediments containing the Messinian evaporites appears to be required to form the lakes.