Explain how deep ocean currents form.

Deep ocean currents (also known as Thermohaline Circulation) are caused by: The sinking and transport of large masses of cool water gives rise to the thermohaline circulation, which is driven by density gradients due to variations in temperature and salinity. The earth's rotation also influences deep ocean currents.

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: