Details for Benchmark: NJ0583
N 42° 01.783 W 091° 42.767 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In LINN county, IA View Original Datasheet
- X 75
- Marker Type:
- bench mark disk
- light structures
- Mark of questionable or unknown stability.
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||Bill93 couldn't find NJ0583
It looks like the old iron culvert has been replaced with a concrete one that extends from the east side of the road to the west side of the old rail bed. There are pieces of concrete lying around that could include the old headwall, but I couldn't identify it.
Documented History (by the NGS)
|01/01/1934 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1934
0.9 MI NW FROM LINN. 0.9 MILE NORTHWEST ALONG THE CHICAGO, ROCK ISLAND AND PACIFIC RAILWAY FROM THE STATION AT LINN, LINN COUNTY, 6 POLES NORTH OF MILEPOST 5, 35 FEET SOUTH OF A CHICAGO, MILWAUKEE, ST. PAUL AND PACIFIC RAILROAD OVERPASS, AT A 3-FOOT IRON PIPE CULVERT, IN THE TOP OF THE CENTER OF THE EAST CONCRETE HEADWALL, 13 FEET EAST OF THE CENTERLINE OF THE TRACK, AND LEVEL WITH THE TRACK. A STANDARD DISK, STAMPED X 75 1934.
- 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.