To ensure the comparability of observation results and to estimate seasonal and year-to year variations in oceanographic variables, it was suggested in Stockholm as early as 1899 that measurements should be made at standard depths and on standard sections.  At the beginning of the 20th century observations started on the Kola Section in the Barents Sea (Knipovich 1906), and by the 1930s, a network of such sections had been developed in the area (Figure 3.2.1).