Details for Benchmark: KX1251
N 40° 24.950 W 079° 54.833 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In ALLEGHENY county, PA View Original Datasheet
- Marker Type:
- NGS Benchmark
- setting not listed - see description
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|Unknown by DOD (MONUMENTED)
|01/01/1966 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1966
2.1 MI W FROM RANKIN. ABOUT 2.1 MILES WEST ALONG THE BALTIMORE AND OHIO RAILROAD FROM THE STATION AT RANKIN, ABOUT 0.45 MILE NORTHEAST OF THE HOMESTEAD BRIDGE OVER THE MONONGAHELA RIVER AND THE TRACK, ABOUT 12 1/2 RAILS SOUTHWEST OF SIGNAL BRIDGE NO. E 321-12, A BRASS PLATE SET IN THE TOP OF A CONCRETE POST PROJECTING 2 INCHES, 57 1/2 FEET EAST AND ACROSS THREE TRACKS FROM MILEPOST NO. 321-17, 39 FEET NORTHEAST OF THE EXTENDED CENTERLINE OF A STREET THAT LEADS WEST FROM THE NORTHWEST SIDE OF THE TRACKS, 4 FEET NORTHWEST IF THE NORTHWEST RAIL OF THE SOUTHEAST ONE OF 4 TRACKS AND IS BETWEEN THE TWO TRACKS AND 1/2 FOOT BELOW LEVEL OF TRACK.
|04/01/1992 by USGS (MARK NOT FOUND)
|RECOVERY NOTE BY US GEOLOGICAL SURVEY 1992
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. WARNING-Repeat measurements at this control monument indicate possible vertical movement.
- 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.