Details for Benchmark: MC0450
N 41° 06.883 W 083° 10.550 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In SENECA county, OH View Original Datasheet
- Marker Type:
- survey disk
- massive structures with deep foundations
- Most reliable and expected to hold position/elevation well.
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Documented History (by the NGS)
|01/01/1903 by USGS (MONUMENTED)
|01/01/1968 by NGS (GOOD)
|DESCRIBED BY NATIONAL GEODETIC SURVEY 1968
AT TIFFIN. AT TIFFIN, IN THE NORTHEAST CORNER OF THE INTERSECTION OF MARKET AND WASHINGTON STREETS, SET IN THE TOP OF THE STONE SILL OF THE SOUTH ONE OF TWO WINDOWS ON THE WEST SIDE OF THE COUNTY COURTHOUSE, 11 FEET NORTH OF THE SOUTHWEST CORNER OF THE COURTHOUSE (STONE BUILDING), 1.7 FEET ABOVE THE LEVEL OF THE SIDEWALK AND ABOUT 3 FEET ABOVE MARKET STREET. NOTE-- THE WINDOW SILL SLOPES TO THE WEST AND THE HIGH POINT OF THE DISK IS OVER THE LETTERS IC OF THE WORD GEOLOGICAL.
|10/23/1992 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1992
IN TIFFIN, AT THE INTERSECTION OF SOUTH WASHINGTON AND EAST MARKET STREETS, IN THE MOST SOUTHERLY STONE WINDOW SILL ON THE WEST SIDE OF THE COURTHOUSE, 43.9 M (144.0 FT) EAST OF THE CENTERLINE OF WASHINGTON STREET, 31.1 M (102.0 FT) NORTH OF THE CENTERLINE OF MARKET STREET, 8.9 M (29.2 FT) SOUTH OF THE CENTER OF THE WEST ENTRANCE TO THE BUILDING, 2.1 M (6.9 FT) NORTH OF THE SOUTHWEST CORNER OF THE BUILDING, AND 0.8 M (2.6 FT) ABOVE THE GROUND SURFACE.
- 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 April 1995.
- 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.