Details for Benchmark: JC0049
N 38° 40.500 W 090° 11.750 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In C OF ST LOUIS county, MO View Original Datasheet
- Marker Type:
- light structures
- Mark of questionable or unknown stability.
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Documented History (by the NGS)
|Unknown by DOD (MONUMENTED)
|01/01/1946 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1946
AT ST LOUIS. AT THE ST. LOUIS GRAND AVENUE WATERWORKS, ST. LOUIS, ON THE NORTH SIDE OF THE EAST ENGINE ROOM, AT THE WEST STEPS OF THE NORTH ENTRANCE, 3.7 FEET ABOVE THE SIDEWALK, IN THE THIRD COURSE OF STONE ABOVE THE GROUND AND 28 INCHES ABOVE THE TOP OF THE SECOND STEP FROM THE BOTTOM. A SMALL HOLE IN THE CENTER OF A COPPER BOLT LEADED HORIZONTALLY INTO THE WALL AND SURROUNDED BY LETTERS USPBM CUT IN THE WALL.
- 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.