Details for Benchmark: MJ0414
N 41° 26.533 W 095° 05.500 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In CASS county, IA View Original Datasheet
- S 162
- Marker Type:
- bench mark disk
- light structures
- Mark of questionable or unknown stability.
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Documented History (by the NGS)
|01/01/1950 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1950
1.1 MI SE FROM MARNE. 0.1 MILE SOUTH ALONG A GRAVELED ROAD FROM THE CHICAGO, ROCK ISLAND AND PACIFIC RAILROAD STATION AT MARNE, THENCE 1.0 MILE SE ALONG STATE HIGHWAY 83, 2 1/2 RAILS NORTHWEST OF SIGNAL TOWER 4448, 98 FEET NORTHEAST OF THE RAILROAD, 12 FEET BELOW THE LEVEL OF THE RAILROAD, 3 FEET ABOVE THE LEVEL OF THE HIGHWAY, SET IN THE TOP OF THE NORTHWEST END OF THE SOUTHWEST HEADWALL OF A RAILROAD CULVERT.
- The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
- The orthometric height was determined by differential leveling and adjusted by the National Geodetic Survey in June 1991.
- The geoid height was determined by GEOID99.
- The dynamic height is computed by dividing the NAVD 88 geopotential number by the normal gravity value computed on the Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45 degrees latitude (g = 980.6199 gals.).
- The modeled gravity was interpolated from observed gravity values.