These are salt fingers. The eerie fingerlike structures are caused by sinking blobs of warm, salty water interleaving with rising blobs of cold, fresh water. This is a thermohaline staircase. Thin ...
Limnology and Oceanography, Vol. 64, No. 2 (March 2019), pp. 650-660 (11 pages) Double diffusion in lakes and oceans can transform vertical gradients into staircases of convectively mixed layers ...