The vertical overturns occurring behind a biplane grid placed in a continuously stratified water channel were measured with a high‐speed vertical density profiler. The resulting scale (LT)rms, known as the Thorpe scale is compared to the Ozmidov scaleLR=(&egr;/N3)1/2and the Eulerian turbulent scalel=2&rgr;′/(d&rgr;¯/dz). For buoyancy‐dominated or stratified turbulence,land (LT)rmsare linearly related, but when all turbulent overturning events have ceased, (LT)rmsis shown to decay at a faster rate. Vertical displacements larger than the Ozmidov scale are observed implying that some previously turbulent scales have become fossil turbulence.