Bench Mark Sheet for 8720692, State Road A1A Bridge FL

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


To reach the Aqua Trak (tide gage) from the junction of State Highway 206 and
State Highway A1A (Ocean Shore Boulevard) in Crescent Beach, go south on State
Highway A1A (Ocean Shore Boulevard) for 7.48 km (4.65 mi) to the north end of
the Matanzas Inlet Bridge, continue south on State Highway A1A (Ocean Shore
Boulevard) for 0.32 km (0.2 mi) to the Aqua Trak (tide gage) on the right
attached to the bridge.


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


                 PRIMARY BENCH MARK STAMPING:  0692 C 1998
                         DESIGNATION:          872 0692 C TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        17692
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 42.2' N (  29.70306)          LONGITUDE:  81° 13.7' W ( -81.22778)


The primary bench mark is a flange-encased rod located 60.14 m (197.3 ft) north
of Barratarin Drive, 17.62 m (57.8 ft) west of the centerline of State Highway
A1A, 6.55 m (21.5 ft) south of the approximate centerline of the entrance
driveway to Matanzas Inlet Park at 18825 A1A South, 1.13 m (3.7 ft) east of a
1.83 m (6.0 ft) tall chainlink fence and 0.37 m (1.2 ft) north of power pole
Number 36540533909 and a carsonite witness post.  The datum point is recessed
0.09 m (0.3 ft) below the level of the NGS logo cap, being the top of a
stainless steel rod driven to refusal at a depth of 7.62 m (25.0 ft) encased in
a 5-inch NGS logo cap flush with the ground and level with State Highway A1A.  A
magnet was placed inside of the NGS logo cap.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


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


                         BENCH MARK STAMPING:  0692 A 1998
                         DESIGNATION:          872 0692 A TIDAL

MONUMENTATION:           Bench Mark disk                       VM#:        17691
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Bridge walkway                        OPUS PID#: DM1492
LATITUDE:   29° 42.3' N (  29.70472)          LONGITUDE:  81° 13.7' W ( -81.22833)


The bench mark is a disk set flush in the top of the bridge deck walkway and
level with State Highway A1A, about 124.36 m (408.0 ft) north of the south end
of the bridge, 7.16 m (23.5 ft) west of the centerline of State Highway A1A,
1.31 m (4.3 ft) east of the concrete bridge rail, and 0.15 m (0.5 ft) west of
the concrete bridge rail.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


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


                         BENCH MARK STAMPING:  0692 D 1998
                         DESIGNATION:          872 0692 D TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        17693
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   29° 42.1' N (  29.70222)          LONGITUDE:  81° 13.7' W ( -81.22750)


The bench mark is a flange-encased rod located 41.45 m (136.0 ft) south of the
approximate centerline of Barratarin Drive, 31.24 m (102.5 ft) north of the
approximate centerline of a driveway at 8875 A1A South, 22.86 m (75.0 ft) south
of the approximate centerline of the driveway at 8852 A1A South, 18.29 m (60.0
ft) west of the centerline of State Highway A1A, 2.53 m (8.3 ft) NW of power
pole Number 36540553209 with 4 guy wires attached, 0.91 m (3.0 ft) WNW of a 6.10
m (20.0 ft) tall pole with a meter box attached, 0.34 m (1.1 ft) north of a
right-of-way marker and 0.30 m (1.0 ft) east of a wire fence and 0.18 m (0.6 ft)
east of a carsonite witness post.  The datum point is recessed 0.03 m (0.1 ft)
below the level of the NGS logo cap, being the top of a stainless steel rod
driven to refusal at a depth of 7.99 m (26.2 ft) encased in a 5-inch NGS logo
cap flush with the ground and level with State Highway A1A.  A magnet was placed
inside of the NGS logo cap.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


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


                         BENCH MARK STAMPING:  COVEF 1934 1978
                         DESIGNATION:          COVE RESET

MONUMENTATION:           Bench Mark disk                       VM#:        17695
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  AQ1723
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   29° 41.9' N (  29.69830)          LONGITUDE:  81° 13.6' W ( -81.22670)


The bench mark is set in the top of a round concrete monument located 27.58 m
(90.5 ft) north of the centerline of Gene Johnson Road, 27.10 m (88.9 ft) south
of the center of a driveway, 18.20 m (59.7 ft) east of the centerline of A1A,
and 0.40 m (1.3 ft) west of a metal witness post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


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


                         BENCH MARK STAMPING:  M 321
                         DESIGNATION:          M 321 RESET

MONUMENTATION:           Tidal Station disk                    VM#:        17696
AGENCY:                  FL Department of Transportation (FLDT) IDB PID#:  AQ2717
SETTING CLASSIFICATION:  Bridge guardrail                      OPUS PID:        
LATITUDE:   29° 41.9' N (  29.69750)          LONGITUDE:  81° 13.5' W ( -81.22583)


The bench mark is a disk set flush in the top of the NW end of the bridge
guardrail and 0.91 m (3.0 ft) above the level of State Highway A1A, 5.61 m (18.4
ft) west of the centerline of State Highway A1A, and 2.41 m (7.9 ft) south of
the north end of the bridge guardrail.  

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


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


                         BENCH MARK STAMPING:  K 321
                         DESIGNATION:          K 321 RESET

MONUMENTATION:           Tidal Station disk                    VM#:        17697
AGENCY:                  FL Department of Transportation (FLDT) IDB PID#:  AQ2715
SETTING CLASSIFICATION:  Bridge guardrail                      OPUS PID:        
LATITUDE:   29° 40.8' N (  29.67917)          LONGITUDE:  81° 13.3' W ( -81.22111)


The bench mark is a disk set flush in the top of the northwest end of the bridge
guardrail and 0.91 m (3.0 ft) above the level of State Highway A1A, 5.61 m (18.4
ft) west of the centerline of State Highway A1A, and 2.41 m (7.9 ft) south of
the north end of the bridge guardrail.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


                            T I D A L   D A T U M S 


Tidal datums at STATE ROAD A1A BRIDGE based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           October 2003 - October 2003
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8720218 BAR PILOTS DOCK, ST JOHNS RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.255
     MEAN HIGH WATER                            MHW    =  1.159
     North American Vertical Datum              NAVD88 =  0.695
     MEAN TIDE LEVEL                            MTL    =  0.605
     MEAN SEA LEVEL                             MSL    =  0.594
     MEAN LOW WATER                             MLW    =  0.050
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0692 C 1998                                 2.978    1.819
     0692 A 1998                                 7.043    5.884
     0692 D 1998                                 2.443    1.284
     COVEF 1934 1978                             2.347    1.188
     M 321                                       6.547    5.388
     K 321                                       6.279    5.120


Foot Notes:

Geodetic heights of the bench marks meet all NOAA/NOS/NGS quality control
standards for Second Order, Class 1 leveling.  It is advised that a confirmation
set of levels be established for bench mark COVEF 1934 1978 to verify height
differences before using tidal bench mark elevation information.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of  8

                                                                                
Station ID: 8720692                         PUBLICATION DATE:  08/25/2011
Name:       STATE ROAD A1A BRIDGE                             
            FL
NOAA Chart: 11486                           Latitude:   29° 42.4' N (  29.70670)
USGS Quad:  Matanzas Inlet                  Longitude:  81° 13.2' W ( -81.22000)


                             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 NGS's Integrated Data Base (IDB PID)
provides geodetic datum based on traditionally leveled and bluebooked ties to
the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/.
The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based
on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/.

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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