Details for Benchmark: AA1720
N 24° 47.467 W 080° 53.067 (NAD 83)
Coordinates may not be exact. Altitude is ADJUSTED and location is SCALED. (more info)
- In MONROE county, FL View Original Datasheet
- 872 3706 F TIDAL
- Marker Type:
- tidal station disk
- pavements (street, sidewalk, curb, apron, etc.)
- Mark of questionable or unknown stability.
Benchmarks may be on private property or in dangerous locations. Obey local laws. By using the services on Geocaching.com you agree to this disclaimer.
Documented History (by the NGS)
|1/1/1982 by FLDNR (MONUMENTED)
|10/19/1990 by FLDNR (GOOD)
|DESCRIBED BY FL DEPT OF NAT RES 1990
TO REACH THE MARK FROM THE POST OFFICE IN LAYTON, GO SOUTHWEST ON U.S. HIGHWAY 1 FOR 4.9 MI (7.9 KM) TO THE SOUTHWEST END OF THE BRIDGE OVER LONG KEY CHANNEL AND THE MARK. LOCATED 21.4 FT (6.5 M) SOUTHEAST OF THE CENTERLINE OF U.S. HIGHWAY 1, 7.35 FT (2.24 M) NORTHEAST OF THE SOUTHWEST END OF THE GUARDRAIL, 1.7 FT (0.5 M) SOUTHWEST OF THE BRIDGE ABUTMENT AND 3.0 FT (0.9 M) ABOVE THE HIGHWAY.
- 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.