Long description

Figure 13

This is a vertical profile of the Atlantic Ocean showing contours of temperature with depth and latitude.

There is a small inset map in the lower right corner. This map is centred on the Atlantic Ocean and spans all latitudes. There is a solid red line running more or less north-south through the middle of the Atlantic Ocean.

The horizontal axis of the main profile represents latitude, but is unlabelled. The axis scale goes from approximately 25° S to 65° N. There are tick marks at intervals of 10°, but numbered tick marks only at 20° intervals from 40° S to 60° N. The latitude of 0° is labelled as 'EQ'.

The vertical axis is labelled 'depth/m'. There are tick marks at intervals of 500 m but numbered only at intervals of 1000 m, from 0 m to 6000 m, with 0 m at the top of the axis.

There are horizontal and vertical gridlines at the numbered axes markers.

Along the bottom of the profile is a grey-coloured area, representing the ocean floor. The depth of the ocean floor starts shallow at 25° S and drops rapidly to below 5000 m at 30° S. It then undulates sharply up and down around the 5000 m depth with peaks at 40° S, EQ, 40° N and then it rises again to near surface at 66° N.

Contours of equal temperature are shown by labelled dashed or solid lines, ranging from 0 °C to 25 °C in intervals of 0.5 °C. The labels are black and very small. The contour lines for temperatures of 0 °C, 10 °C and 20 °C are bold and the labels are white.

The temperature is also indicated by colour coding and this is indicated by the vertical colour key bar to the right of the profile. The key bar is labelled '°C' and is marked from 0 °C at the bottom to 25 °C at the top in intervals of 5 °C. The colour of the bar changes from purple at the bottom (low temperature) through blue, green, yellow, orange, red and then to pale red and orange again at the top (high temperature).

The general pattern of the profile shows a narrow band of red/orange colour at the surface indicating high temperatures and then a steady decrease in temperature with increasing depth.

The warmer temperatures extend further down between 20° N and 60° N as evidenced by the bulge of the green colour down to depths of almost 2000 m in this latitude.

There is a distinct band of purple at depth from EQ to 25° S and this band of very low temperatures follows the ocean floor to the surface at 25° S. The spread of this band of very low temperature stops abruptly at the peak of ocean floor at EQ where the ocean floor rises sharply to 2000 m.