How large is the North American Datum (NAD) 27 to NAD 83 shift?
Within the conterminous 48 states, the North American Datum of 1927 (NAD 27) to the North American Datum of 1983 (NAD 83) shift of the latitude/longitude graticule (lines showing parallels of latitude and meridians of longitude for the earth) is in the range of 10-100 ground meters. Changes to UTM values are generally larger, around 200 meters, and changes for other coordinate systems are different.
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Related Content
Why are USGS historical topographic maps referenced to outdated datums?
Why are the NAD 83 position values so far from the NAD 27 values? Were the old coordinates wrong?
How are different map projections used?
What location coordinates (datum) does the Geographic Names Information System use?
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A topographic map tells you where things are and how to get to them, whether you're hiking, biking, hunting, fishing, or just interested in the world around you. These maps describe the shape of the land. They define and locate natural and manmade features like woodlands, waterways, important buildings, and bridges. They show the distance between...
North American Datum of 1983, map data conversion tables; Alaska
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North American Datum of 1983, map data conversion tables; United States west of 96 degrees West longitude (including Hawaii)
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