Regularly spaced steps in the main thermocline near Bermuda

The main thermocline of the ocean off Bermuda is not a smooth gradient of temperature and salinity but consists of a remarkably regular series of steps of homogeneous layers 3 to 5 meters thick which alternate with transition layers 10 to 15 meters thick in which the temperature and salinity shift 0.30 to 0.50°C and 0.04 to 0.10‰. These structures exist to a distance at least 130 km from the island, and we presume that they are a ubiquitous feature of most of the main thermocline throughout the Sargasso Sea. Their horizontal extent is between 400 and 1000 meters. Their lifetime is unknown.