What Is A Depression On A Topographic Map

A depression is a low point in the ground or a sinkhole.

What is a depression on a topographic map. These maps are prepared based on a detailed survey of the areas concerned. Click here to see list of references authorities sources and geographical terms as used in this glossary. The phrase usgs topographic map can refer to maps with a wide range of scales but the scale used for all modern usgs topographic maps is 1 24 000. And a point outsidea contour is higherthan the contour.

These maps are revised periodically to update. Use the drop down menus to answer the questions about the topographic map. A topographic map with points a and b labeled. Depression in this case essentially means a hole.

How are areas of depression represented on a topographic map answers a depression is shown by contour lines with small marks pointing toward the lowest point of the depression. It could be described as an area of low ground surrounded by higher ground in all directions or simply a hole in the ground. It is a ditch or gully or pit where the elevation decreases towards the center. So look what we ve done we ve made up a new type of contour called a depression contour.

They will appear as a series of closed circles one inside the other. Point b is on a contour line with number 6800 and image of a table. Point a is on a contour line with number 7000. A depression is sort of the opposite of a hill.

A closed contour inside of which the ground or geologic structure is at a lower elevation than that outside and distinguished on a map from other contour lines by hachures marked on the downslope or downdip side. Symbology on a topographic map concentric contour lines drawn with hachures to indicate a closed depression or basin. That covers a quadrangle that measures 7 5 minutes of longitude and latitude on all sides so these are also referred to as 7 5 minute maps quadrangle maps or quad maps modern topographic maps for alaska have a scale of 1 25 000 and cover a variable distance of longitude. Each topographic map has a unique name.

Definition of depression contour. For hachured contours a point insidea contour is lowerthan the contour. Topographical maps may be used for many purposes. It s marked with little teeth called hachures.

Contour lines on a map depict a spur with the u or v pointing away from high ground. A topographic map is a kind of map which uses contour lines or other ways to show elevation and topography. The value of the index contour line at point a is feet. Topo maps are usually very detailed with a large scale though some are not.

Mineral and or locality. On a topographic map it is demonstrated by hatched lines which. Concentric contour lines drawn without hachure marks indicate a hill. Depressor glossary search.

The symbol at point b indicates a area.