PREPARATION OF ATLAS CHARTS
processing of almost all the data mentioned in the preceding section
involved the use of automatic data processing (ADP) equipment at some
stage. The data were therefore already stored on punched cards or
magnetic tape and readily available for plotting in various forms by
The vertical sections of physical properties, dissolved oxygen, and nutrient chemicals were prepared almost entirely by computer plotter, including drawing of the contours. Hand work included accenting certain contours and the addition of contour labels. For phytoplankton properties and upper atmosphere sections the outline of the section and depths, or heights, of sampling were plotter-drawn, and then hand-drawn contours were traced onto the section from a preliminary contoured version.
There was more variety in the methods used to prepare the charts of horizontal distributions. The options open to the contributors included hand or machine plotting of station positions and the data to be contoured, and then hand or machine drawing of the contours. Copies of the standard base map on which to plot data were available to all contributors. The base map was adapted from two U.S. Naval Oceanographic Office charts and is a Mercator projection. Some charts were plotted and contoured by hand; others were plotted automatically and contoured by hand. This latter was the most popular method of chart preparation In either of the above methods the draftsman overlaid the preliminary version with a clean base map and copied the contours and station positions and applied shading as necessary. The charts showing zooplankton standing stock were plotted and contoured automatically. Drafting work on these charts was limited to touch-up work and application of shading.