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Some symbols describe the sea bed with information such as its depth, materials as well as possible navigational hazards such as shipwrecks. Other symbols show the position and characteristics of navigational aids such as buoys, lights, lighthouses, coastal and land features and structures that are useful for position fixing. The abbreviation ...
A map symbol or cartographic symbol is a graphical device used to visually represent a real-world feature on a map, working in the same fashion as other forms of symbols. Map symbols may include point markers, lines, regions, continuous fields, or text; these can be designed visually in their shape, size, color, pattern, and other graphic ...
Water glyphs are a recurring type of petroglyph found across the American southwest, but primarily in southern Utah, northern Arizona, and Nevada. The symbols are thought to be of ancient origin (perhaps created by the Ancestral Puebloans ) and have been dated using x-ray fluorescence to around 2000 years.
A cardinal mark is a sea mark (a buoy or other floating or fixed structure) commonly used in maritime pilotage to indicate the position of a hazard and the direction of safe water. Cardinal marks indicate the direction of safety as a cardinal ( compass ) direction ( north , east , south or west ) relative to the mark.
Typography, as an aspect of cartographic design, is the craft of designing and placing text on a map in support of the map symbols, together representing geographic features and their properties. It is also often called map labeling or lettering , but typography is more in line with the general usage of typography .
This map of United States water resource subregion hydrologic units updated boundaries to include the ocean as well as the portions of the basins that cross international borders For the use of hydrologists, ecologists, and water-resource managers in the study of surface water flows in the United States, the United States Geological Survey ...
Examples of Safe Water Marks An example of a Safe Water Mark in Limfjord, Denmark. A safe water mark, as defined by the International Association of Lighthouse Authorities, is a sea mark used in maritime pilotage to indicate the end of a channel. They usually imply that open, deep and safe water lies ahead.
For deep-water bathymetry, this is typically Mean Sea Level (MSL), but most data used for nautical charting is referenced to Mean Lower Low Water (MLLW) in American surveys, and Lowest Astronomical Tide (LAT) in other countries. Many other datums are used in practice, depending on the locality and tidal regime.