Final answer:
A topographic depression on a map is delineated by elevation and contour lines, specifically closed contour lines with hachure marks indicating lower elevation within. Topographic maps serve as essential tools for representing the Earth's surface in three dimensions.
Step-by-step explanation:
The two features that delineate if a map contains a topographic depression are elevation and contour lines. When looking at a topographic map, depressions are indicated by closed contour lines that have hachure marks or short straight lines on the inside of the loop pointing towards the area of lower elevation. It is important to recognize that as contour lines on a map get closer together, the steepness of the terrain increases, which could signify not just depressions but also hills and inclines.
Topographic maps are incredibly useful tools for geologists, hikers, engineers, and anyone needing detailed information about Earth's surface, as they represent the three-dimensional landscape on a two-dimensional map. The shape of the Earth's surface, including various landforms and potential geological hazards, can be visualized through careful examination of these maps.