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Bench Mark Sheet for 8720203, BLOUNT ISLAND 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  6

                                                                                
Station ID: 8720203                         PUBLICATION DATE:  02/05/2004
Name:       BLOUNT ISLAND BRIDGE                              
            FL
NOAA Chart: 11491                           Latitude:   30° 24.8' N (  30.41330)
USGS Quad:  EASTPORT                        Longitude:  81° 32.7' W ( -81.54500)


To reach the tidal bench marks from the intersection of New Berlin Road and
State Road 105 in Jacksonville, proceed 2.3 km (1.4 mi) east on State Road 105
to the residence at 4822 Heckscher Drive on the south side of the road.  The
bench marks are located along Heckscher Drive.  The tide gage and staff were
located on a privately owned pier behind the residence.


                         T I D A L   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8720203                         PUBLICATION DATE:  02/05/2004
Name:       BLOUNT ISLAND BRIDGE                              
            FL
NOAA Chart: 11491                           Latitude:   30° 24.8' N (  30.41330)
USGS Quad:  EASTPORT                        Longitude:  81° 32.7' W ( -81.54500)


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


                 PRIMARY BENCH MARK STAMPING:  P 325 1970
                         DESIGNATION:          P 325

MONUMENTATION:           Bench Mark disk                       VM#:         5084
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  BC0285
SETTING CLASSIFICATION:  Concrete base of a tower              OPUS PID:        
LATITUDE:   30° 24.8' N (  30.41389)          LONGITUDE:  81° 32.7' W ( -81.54417)


The primary bench mark is a disk set on the top of the SW corner of the SE
concrete base of the middle one of three transmission line towers, 1.3 km (0.8
mi) west of the bridge over Browns Creek, 0.6 km (0.4 mi) NE of the east end of
the old wooden bridge over San Carlos Creek, which is now a fishing bridge on
Heckscher Drive, 64.92 m (213.0 ft) north of the centerline of Heckscher Drive,
0.30 m (1.0 ft) NW of a carsonite witness post, and 1.07 m (3.5 ft) above the
ground.  Note:  The mark has been defaced, use with caution.



                         BENCH MARK STAMPING:  0203 A 1982
                         DESIGNATION:          872 0203 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         5085
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  BC2482
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   30° 24.7' N (  30.41222)          LONGITUDE:  81° 32.7' W ( -81.54556)


The bench mark is a disk set in a concrete monument, 0.2 km (0.1 mi) east of the
San Carlos Creek Bridge, 17.10 m (56.1 ft) SE of the centerline of Heckscher
Drive, 3.44 m (11.3 ft) WSW of the north fence corner of Jacksonville City
property, 3.38 m (11.1 ft) SW of a utility pole, 1 m (3 ft) NNW of a fence line,
and 0.76 m (2.5 ft) NNW of a carsonite witness post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8720203                         PUBLICATION DATE:  02/05/2004
Name:       BLOUNT ISLAND BRIDGE                              
            FL
NOAA Chart: 11491                           Latitude:   30° 24.8' N (  30.41330)
USGS Quad:  EASTPORT                        Longitude:  81° 32.7' W ( -81.54500)


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


                         BENCH MARK STAMPING:  L 325
                         DESIGNATION:          L 325

MONUMENTATION:           Survey disk                           VM#:         5086
AGENCY:                  Florida Department of Transportation
                         (FLDOT)                               IDB PID#:  BC0283
SETTING CLASSIFICATION:  Concrete walkway                      OPUS PID:        
LATITUDE:   30° 24.7' N (  30.41170)          LONGITUDE:  81° 33.0' W ( -81.55000)


The bench mark is a disk set on top of the south concrete walkway of the highway
bridge over San Carlos Creek, 5.55 m (18.2 ft) south of the centerline of the
highway, 0.49 m (1.6 ft) east of the west end of the walkway, and 0.3 m (1 ft)
above highway level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8720203                         PUBLICATION DATE:  02/05/2004
Name:       BLOUNT ISLAND BRIDGE                              
            FL
NOAA Chart: 11491                           Latitude:   30° 24.8' N (  30.41330)
USGS Quad:  EASTPORT                        Longitude:  81° 32.7' W ( -81.54500)


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


                         BENCH MARK STAMPING:  M 325
                         DESIGNATION:          M 325

MONUMENTATION:           Survey disk                           VM#:         5087
AGENCY:                  Florida Department of Transportation
                         (FLDOT)                               IDB PID#:  BC0284
SETTING CLASSIFICATION:  Concrete walkway                      OPUS PID:        
LATITUDE:   30° 24.7' N (  30.41170)          LONGITUDE:  81° 32.8' W ( -81.54670)


The bench mark is a disk set on the north concrete walkway of the highway bridge
over San Carlos Creek, 5.33 m (17.5 ft) north of the centerline of the highway,
0.46 m (1.5 ft) west of the east end of walkway, and 0.3 m (1 ft) above highway
level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 8720203                         PUBLICATION DATE:  02/05/2004
Name:       BLOUNT ISLAND BRIDGE                              
            FL
NOAA Chart: 11491                           Latitude:   30° 24.8' N (  30.41330)
USGS Quad:  EASTPORT                        Longitude:  81° 32.7' W ( -81.54500)


                            T I D A L   D A T U M S 


Tidal datums at BLOUNT ISLAND BRIDGE based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           September 1977 - November 1977
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8720220 MAYPORT


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.145
     MEAN HIGH WATER                            MHW    =  1.086
     North American Vertical Datum              NAVD88 =  0.697
     MEAN SEA LEVEL                             MSL    =  0.593
     MEAN TIDE LEVEL                            MTL    =  0.557
     MEAN LOW WATER                             MLW    =  0.028
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     P 325 1970                                  3.852    2.766
     0203 A 1982                                 2.015    0.929
     L 325                                       4.421    3.335
     M 325                                       4.416    3.330


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

                                                                                
Station ID: 8720203                         PUBLICATION DATE:  02/05/2004
Name:       BLOUNT ISLAND BRIDGE                              
            FL
NOAA Chart: 11491                           Latitude:   30° 24.8' N (  30.41330)
USGS Quad:  EASTPORT                        Longitude:  81° 32.7' W ( -81.54500)


                             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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Products available at 8720203 BLOUNT ISLAND BRIDGE, FL

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services