Details for Benchmark: MJ0189
N 41° 29.467 W 094° 56.767 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In CASS county, IA View Original Datasheet
- V 99
- Marker Type:
- bench mark disk
- light structures
- Mark of questionable or unknown stability.
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Documented History (by the NGS)
|01/01/1935 by CGS (MONUMENTED)
|01/01/1941 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1941
1.4 MI N FROM LORAH. 1.4 MILES NORTH ALONG THE CHICAGO, ROCK ISLAND AND PACIFIC RAILROAD FROM THE STATION AT LORAH, CASS COUNTY, MIDWAY BETWEEN POLES 448+05 AND 448+06, 510 FEET SOUTH OF THE CROSSING OF U.S. HIGHWAY 71, 48 FEET EAST OF THE CENTERLINE OF THE TRACK, 18 FEET WEST OF THE CENTERLINE OF THE HIGHWAY, AT A 5-BY-5-FOOT CONCRETE-BOX CULVERT, IN THE TOP OF THE NORTH END OF THE WEST HEADWALL, AND ABOUT 4 FEET LOWER THAN THE TRACK. A STANDARD DISK, STAMPED V 99 1935.
|01/01/1969 by USGS (MARK NOT FOUND)
|RECOVERY NOTE BY US GEOLOGICAL SURVEY 1969
MARK NOT FOUND.
- 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.