Small-scale structure in the fields of temperature, salinity, density, and/or velocity. The term finestructure refers in the ocean to structures of vertical scale smaller than 100 m and larger than 1 m, usually associated with small-scale physical factors that may cause mixing, but not with the mixing events themselves. Examples are interleaving motions, inertial and internal waves, and vertical modes. Note the overlap in the vertical scale with that of microstructure.