Details for Benchmark: MB0030
N 41° 58.200 W 080° 18.600 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In ERIE county, PA View Original Datasheet
- X 61
- 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)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1935
3.2 MI S FROM GIRARD. 3.2 MILES SOUTH ALONG THE BESSEMER AND LAKE ERIE RAILROAD FROM THE STATION AT GIRARD, 1,770 FEET SOUTH OF MILEPOST E 18.1, 27 FEET SOUTH OF POLE 5+22, AT AN 8-FOOT CONCRETE BOX CULVERT, IN THE TOP OF THE TOP STEP OF THE NORTHEAST WING WALL, 24 FEET EAST OF THE EAST RAIL, AND 11 FEET LOWER THAN THE TRACK. A STANDARD DISK, STAMPED X 61 1935.
|01/01/1961 by NGS (MARK NOT FOUND)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1961
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.