Details for Benchmark: MC1002
N 41° 30.867 W 082° 56.567 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In OTTAWA county, OH View Original Datasheet
- 906 3083 WL 107 USLS
- Marker Type:
- survey disk
- abutments and piers of large bridges
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1937 by USLS (MONUMENTED)
|01/01/1980 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1980
IN PORT CLINTON. IN PORT CLINTON, IN THE STATE HIGHWAY 163 BRIDGE OVER PORTAGE RIVER, SET VERTICALLY IN THE WEST FACE OF THE FIRST CONCRETE PIER ON THE SOUTH SIDE OF THE RIVER, 3.7 METERS (12 FEET) SOUTH OF THE NORTHWEST CORNER OF THE PIER. THE MARK IS 1.2 M ABOVE GROUND.
- 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.