To sum up, contour lines not only show a variety of geomorphological features, but also reflect the geometric precision of the map. We use thinly or thickly spaced contour lines to show gentle or steep slopes smooth and solid, winding irregular contour lines depict lilhological character and the degree of cryogenetic weathering. In the firn basin, the contour lines show a concave shape, like an armchair. When showing glacial movement, contour lines on a glacier tongue become very convoluted, but are arranged to show a convex form on the lower reaches of the glacier. Occasionally, because of limitations of scale, one can accept a degree of simplification in order to depict a particular geomorphological feature.įor example: a glacial trough is U-shaped the side of a glaciated valley steep and concave horns and arêtes are sharply defined, with a “sawtooth” shape. Contour lines, drawn on such scales, should be drawn as accurately as possible simplification by generalisation should be avoided. Generally, the scale of a glacier map is between 1:10 000 and 1:50 000 and the best is 1:25 000. It should show all glacial geomorphological features, not merely the static relief, but also the dynamic aspects, with such technical and artistic expression, in respect of points, lines, symbols, brush-shading, use of colours, etc., as to bring Out the natural landscape of the glacier vividly before the eyes of glaciologists and scientists who use it.ĭrawing contour lines from terrestrial photogrammetric survey data is a very good method (Wang Wenying, 1981) of showing glacial geomorphological forms in detail. The perfect glacier map should be based strictly on a mathematically accurate survey.
These considerations have been the subjects of research into glacier surveying and mapping for many years. Authenticity, so that glacial geomorphological features can be portrayed accurately and objectively. Precision, so that accurate measurements can be taken from the map.Ģ. The main requirements of glacier mapping are:ġ. Glaciers developing on high mountains are produced by the cold climate they, in turn, produce the special, glacial topography. It not only provides the basic data for glaciological research, but also is a medium for showing the results. It shows the geomorphological features of an alpine area covered by ice and snow. A glacier map is a special scientific map.
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