Details for Benchmark: JB1381
N 38° 30.167 W 089° 58.817 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In ST CLAIR county, IL View Original Datasheet
- S 114
- Marker Type:
- bench mark disk
- set into the top of a round concrete monument
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|01/01/1935 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1935
AT BELLEVILLE. AT BELLEVILLE, ST. CLAIR COUNTY, ON THE ILLINOIS CENTRAL RAILROAD, AT THE CROSSING OF STATE HIGHWAY 13, 70 FEET NORTH OF THE CENTERLINE OF THE HIGHWAY, 15 FEET WEST OF THE CENTERLINE OF THE SOUTHBOUND TRACK, 10 FEET NORTH OF A RIGHT-OF-WAY FENCE. A STANDARD DISK, STAMPED S 114 1935 AND SET IN THE TOP OF A CONCRETE POST PROJECTING 4 INCHES ABOVE GROUND.
|01/01/1987 by USPSQD (MARK NOT FOUND)
|RECOVERY NOTE BY US POWER SQUADRON 1987 (JWO)
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.