By making use of chathamtownfc.net map maker, take a virtual field-trip to check out landforms and also terrain functions on topographic map and also Google earth – example video: http://youtu.be/EfDgTPWpMK4

Mountain pass - Col - Saddle edge Lines

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A mountain pass is a low suggest between two areas of higher elevation. It"s additionally defined together a gap or a dive in a ridge crest. Alternate names include saddle, gap, notch and also col. A col is a saddle-like space in one arete. It is formed by headward erosion of two glacier cirques in the direction of each other which carve a void in an arete. In the adhering to images and also the topo map (1:20000), the happen is located between two peaks v its lowest suggest at an elevation of 2125m. It likewise divides the 2 valleys or drainages located to the top and also bottom next of the photo. Streams originating from high floor on either side of the pass circulation into these drainages.

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Attributions for "mountain pass" Google earth images: ©2010 Google; ©2010 Cnes/Spot Image; image © 2010 province of british Columbia

Cliff edge Lines

A cliff is a really steep, vertical or overhanging absent face. Cliffs are represented by an extremely close (or periodically touching) edge lines. In the case of an overhanging cliff or a cave, the edge lines would certainly intersect every other, that is at the same place on earth"s surface we need to indicate two various elevations; in such cases the lower elevation contours are attracted by dashed lines. Additionally note the if a function such as a little cliff is shorter than the edge interval, climate it might not display up on the map. Because that exmaple a 15m cliff band may not be detected on a topo map through a 40m contour interval.

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In the snapshot above we room looking in ~ rock faces of two peaks native northeast. The two pictures to the right show top see of the peaks v north pointing up. Contours are closest or emotional on the steepest part of the cliffs. Attributions for "cliff" Google earth sattelite images: ©2010 Google; picture © 2010 Europa Technologies; image © 2010 IMTCAN

Depression edge Lines

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A depression is a low point in the ground i beg your pardon is surrounded by higher ground in every directions. Examples of depressions incorporate volcanic craters, sinkholes, pit craters, and impact craters.

together we"ve seen, a collection of concentric closed border (i.e. Rarely often, rarely circles) are supplied to stand for hills, hill summits, knolls, horns, etc. In such situations the inside circles have actually a higher elevation 보다 their outer surrounding. A depression is represented by a collection of concentric close up door contours v the inner contours having actually lower elevation than their outer surrounding. There are small tick marks or hachures on these contour present pointing towards reduced elevation. Such contours are called hachured contour lines (also viewed written as hatchured) or depression contour lines.

The image with the 3 closed hachured contours represents a depression; the key decreases towards the middle. The contour interval is 20m. The area inside the 1260m edge should have an elevation higher than 1240m and also less then 1260m. The hill in the photo has actually a depression or crater on top (maybe a cinder cone v breached crater). The depression contour line in the middle has actually an elevation of 5700ft v a contour interval of 100ft, as such the shortest elevation in the center of crater is somewhere in between 5600ft and also 5700ft elevation. The high ridge line on the left next of the crater is sorrounded through 5900ft contour line. In this instance the elevation increases inside the attached contour, therefore the key of the high ridge is over 5900ft and also less 보다 6000ft.


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Attributions because that "depression" Google planet image: ©2010 Google; image © 2010 district of british Columbia

utilizing chathamtownfc.net Map Maker, develop a shaded relief map (hill shading), as shown in Map an equipment Examples, in stimulate to better practice topo map reading and terrain identification.