http://academic.brooklyn.cuny.edu/geology/leveson/core/linksa/depression.html

DEPRESSION CONTOURS - GETTING INTO AND OUT OF A HOLE ... "Here's a little table to show the paths, the slopes, and which contours you cross in ...

https://www.mindat.org/glossary/depression_contour

A closed contour, inside of which the ground or geologic structure is at a lower ... to see list of references, authorities, sources and geographical terms as used in ...

http://geokov.com/education/mountain-pass-cliff.aspx

Mountain Pass, Cliff, Depression and Contour Lines ... a small cliff is shorter than the contour interval, then it may not show up on the map. ... closed contours (i.e. irregular circles) are used to represent hills, mountain summits, knolls, horns, etc.

https://gisgeography.com/contour-lines-topographic-map/

Feb 23, 2018 ... Contour lines have constant values on them such as elevation. But it's also used in meteorology (isopleth), magnetism (isogon) & even drive-time (isochrones) ... depression contour lines label. And this isn't just any ...

https://socratic.org/questions/how-do-contour-lines-show-hills-and-depressions

Jan 26, 2015 ... Contour lines are used in a map to portray differences in elevation. ... the farther apart lines tend to indicate a depression in the landscape.

https://en.wikipedia.org/wiki/Contour_line

A contour line of a function of two variables is a curve along which the function has a constant .... If a loop instead represents a depression, some maps note this by short lines ... Contour maps are used to show the below ground surface of geologic strata, fault surfaces (especially low angle thrust faults) and unconformities.

http://www.iupui.edu/~geogdept/g108/lab_3.htm

-To develop basic skills used in topographic map interpretation. ... geography is the need to portray data that have been collected to show spatial variability. ... Depression contours have hachure marks on the downhill side, always close, and ...

https://www.reference.com/science/depression-contour-line-b9aab536edcf9d7c

A depression contour line is a marking on a map indicating a low point of land completely surrounded by more elevated land. The area is represented by closed  ...

http://faculty.chemeketa.edu/afrank1/topo_maps/contour_interval.htm

Contour lines can be drawn for any elevation, but to simplify things, only lines for certain elevations are ... For example the maps on the previous page used a 10 ft contour interval. ... But we can see it is between the 700 and 800 contour line.

https://pubs.usgs.gov/gip/TopographicMapSymbols/topomapsymbols.pdf

usually indicate similar classes of information: topographic contours ... At one time, purple was used as a revision color to show all feature ... Depression. Cut. Fill.