Superseded Bench Mark Sheet for 8729022, ST. ANDREW SOUND, EAST END FL

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  11/25/1987
Station ID: 8729022                                SUPERCEDED DATE:   04/21/2003
Name:       TYNDALL AIR FORCE BASE, ST. ANDREWS SOUND, EAST EN
            FLORIDA
NOAA Chart: 11389                                  Latitude:         29° 58.2' N
USGS Quad:  BEACON HILL                            Longitude:        85° 28.8' W


To reach the tidal bench marks from the intersection of U.S. Highway 98 and
County Road 386 in Mexico Beach, proceed west on U.S. Highway 98 for 4.4 miles
(7.1 km) to Tyndall Air Force Base, then continue west on the main drive for 1.1
miles (1.8 km) to the Directorate of Field Technology facility.  The bench marks
are along the main drive leading to the facility.  The tide gage and staff were
located on the east end of Tyndall Air Force Base Life Support Dock.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  9022 A 1976

MONUMENTATION:           Survey Disk                               VM#:     9949
AGENCY:                                                            PID#:  AS0867
SETTING CLASSIFICATION:  Concrete Stairway


The bench mark is set flush in the south side of a concrete stairway on the west
side of the main building at the Directorate of Field Technology facility, 190
feet (58 m) NNW of Bench Mark SOUND 1956, 70 feet (21 m) NNW of the centerline
of a circular drive, 0.85 foot (0.26 m) north of the south side of the stairs,
and 0.65 foot (0.20 m) west of the west edge of the stairs.



                         BENCH MARK STAMPING:  SOUND 1956

MONUMENTATION:           Survey Disk                               VM#:     9947
AGENCY:                                                            PID#:  AS0005
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in the top of a concrete monument in front of the main
building at the facility, 155.5 feet (47.4 m) SW of the SE corner of the
building, 35.5 feet (10.8 m) north of the centerline of the main drive leading
to the facility, 2.5 feet (0.8 m) SE of a white wooden witness post, and level
with the road.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  11/25/1987
Station ID: 8729022                                SUPERCEDED DATE:   04/21/2003
Name:       TYNDALL AIR FORCE BASE, ST. ANDREWS SOUND, EAST EN
            FLORIDA
NOAA Chart: 11389                                  Latitude:         29° 58.2' N
USGS Quad:  BEACON HILL                            Longitude:        85° 28.8' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  E 1000 1961

MONUMENTATION:           Survey Disk                               VM#:     9948
AGENCY:                                                            PID#:  AS0866
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set flush in a concrete monument, about  350 feet (107 m) NE
of the shoreline, 64.7 feet (19.7 m) north of the centerline of the main drive
leading to the facility, and 1 foot (0.3 m) south of a wooden witness post with
sign.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  11/25/1987
Station ID: 8729022                                SUPERCEDED DATE:   04/21/2003
Name:       TYNDALL AIR FORCE BASE, ST. ANDREWS SOUND, EAST EN
            FLORIDA
NOAA Chart: 11389                                  Latitude:         29° 58.2' N
USGS Quad:  BEACON HILL                            Longitude:        85° 28.8' W


                            T I D A L   D A T U M S 


Tidal datums at TYNDALL AIR FORCE BASE, ST. ANDREWS SOUND, EAST EN based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           JULY-AUGUST 1976
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8729015 ALLANTON, EAST BAY


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:

     HIGHEST OBSERVED WATER LEVEL (05/28/1976)         =   2.24
     MEAN HIGHER HIGH WATER                     MHHW   =   1.45
     MEAN HIGH WATER                            MHW    =   1.27
     MEAN TIDE LEVEL                            MTL    =   0.71
     MEAN LOW WATER                             MLW    =   0.15
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (07/10/1976)         =  -0.33

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     9022 A 1976                                10.34      9.07
     SOUND 1956                                  5.68      4.41
     E 1000 1961                                 6.59      5.32


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  4

                                                   PUBLICATION DATE:  11/25/1987
Station ID: 8729022                                SUPERCEDED DATE:   04/21/2003
Name:       TYNDALL AIR FORCE BASE, ST. ANDREWS SOUND, EAST EN
            FLORIDA
NOAA Chart: 11389                                  Latitude:         29° 58.2' N
USGS Quad:  BEACON HILL                            Longitude:        85° 28.8' W


                             D E F I N I T I O N S


Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal
Datum Epoch.  It pertains to local mean sea level and should not be confused
with the fixed datums of North American Vertical Datum of 1988 (NAVD88).

NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum
constraint adjustment of Canadian/Mexican/United States leveling observations.
Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as
the single initial constraint.  NAVD88 replaces NGVD29 as the national
standard geodetic reference for heights.  Bench mark elevations relative to
NAVD88 are available from NGS through the World Wide Web at 
National Geodetic Survey.

NGVD29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded.  NGVD29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads.  NGVD29 was originally derived from a general
adjustment of the first-order leveling networks of the U.S. and Canada after
holding mean sea level observed at 26 long term tide stations as fixed.
Numerous local and wide-spread adjustments have been made since establishment in
1929.  Bench mark elevations relative to NGVD29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at 
National Geodetic Survey.

NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to
local MSL and other tidal datums may not be consistent from one location to
another.

The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique
identifiers for bench marks in the tidal and geodetic databases, respectively.
Each bench mark in either database has a single, unique VM# and/or PID# assigned.
Where both VM# and PID# are indicated, both tidal and geodetic elevations are
available for the bench mark listed.

The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD88 elevations.
The NAVD88 elevation relationship shown in the table is derived from an average
of several bench mark elevations relative to tide station datum.  As a result of
this averaging, NAVD88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD88 elevations listed for
each bench mark in the NGS database.

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Products available at 8729022 ST. ANDREW SOUND, EAST END, FL