Details for Benchmark: HT0309
N 37° 30.583 W 122° 06.700 (NAD 83)
Coordinates may not be exact. Altitude is VERTCON and location is SCALED. (more info)
- In ALAMEDA county, CA View Original Datasheet
- V 553
- Marker Type:
- bench mark disk
- massive structures
- Probably hold position/elevation well.
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Documented History (by the NGS)
|01/01/1956 by CGS (MONUMENTED)
|DESCRIBED BY COAST AND GEODETIC SURVEY 1956
AT DUMBARTON BRIDGE. AT DUMBARTON BRIDGE, IN TOP OF THE CONCRETE CURB OVER BENT 117, 177.4 FEET SOUTHWEST OF THE NORTHEAST END OF THE BRIDGE, 177.0 FEET SOUTHWEST OF TIDAL 9, 11 1/2 FEET SOUTHEAST OF THE CENTER LINE OF THE BRIDGE, AND ABOUT 0.8 FOOT HIGHER THAN THE BRIDGE FLOOR.
|01/01/1966 by NGS (GOOD)
|RECOVERY NOTE BY NATIONAL GEODETIC SURVEY 1966
RECOVERED IN GOOD CONDITION.
- The horizontal coordinates were scaled from a topographic map and have an estimated accuracy of +/- 6 seconds.
- The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height (displayed under SUPERSEDED SURVEY CONTROL.) The vertical order pertains to the superseded datum.
- This Tidal Bench Mark is designated as VM 8151 by the Center for Operational Oceanographic Products and Services.
- This Tidal Bench Mark is designated as VM 11712 by the Center for Operational Oceanographic Products and Services.
- The geoid height was determined by GEOID99.