Details for Benchmark: AA1731
N 24° 50.650 W 080° 44.900 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In MONROE county, FL View Original Datasheet
- 872 3868 F TIDAL
- Marker Type:
- tidal station disk
- retaining walls, concrete ledge, etc.
- May hold, but of type commonly subject to surface motion.
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Documented History (by the NGS)
|1/1/1987 by FLDNR (MONUMENTED)
|DESCRIBED BY FL DEPT OF NAT RES 1987
TO REACH THE MARK FROM THE POST OFFICE IN ISLAMORADA, GO SOUTHWEST ON U.S. HIGHWAY 1 FOR 9.9 MI (15.9 KM) TO THE NORTHEAST END OF THE OLD BRIDGE OVER CHANNEL NUMBER 2 AND THE MARK, SET IN THE NORTH WING WALL OF THE BRIDGE. LOCATED 36.5 FT (11.1 M) SOUTHEAST OF THE NORTHWEST END OF THE WINGWALL AND 43.5 FT (13.3 M) NORTH OF BENCH MARK K 69 RESET 1936.
- 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 May 1994.
- 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.