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Bench Mark Sheet for 8724211, BIG PINE KEY VIADUCT 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8724211                         PUBLICATION DATE:  06/09/2003
Name:       BIG PINE KEY VIADUCT                              
            FL
NOAA Chart: 11445                           Latitude:   24° 40.2' N (  24.67000)
USGS Quad:  BIG PINE KEY                    Longitude:  81° 22.1' W ( -81.36830)


To reach the tidal bench marks from the post office in Marathon, proceed 31.9 km
(19.8 mi) SW on U.S. Highway 1 to a gravel road on the right, then 0.1 km (0.05
mi) north along the gravel road to the first canal.  The bench marks are located
in the vicinity of the canal and near the gravel road.  The tide gage and staff
were located at the east end of the first canal, north of U.S. Highway 1.


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


                 PRIMARY BENCH MARK STAMPING:  NO 1 1971
                         DESIGNATION:          872 4211 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:         8912
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA0792
SETTING CLASSIFICATION:  Concrete walkway                      OPUS PID:        
LATITUDE:   24° 40.2' N (  24.67000)          LONGITUDE:  81° 22.1' W ( -81.36830)


The primary bench mark is a disk set in a concrete walkway around the canal,
located at the east end of the first canal north of U.S. Highway 1, 73.61 m
(241.5 ft) north of the centerline of U.S. Highway 1, 37 m (123 ft) west of the
centerline of the gravel road, 23.56 m (77.3 ft) west of bench mark J 328 1970,
2 m (7 ft) south of the south side of the canal, 0.12 m (0.4 ft) north of a low
cinder block wall, and 0.09 m (1.0 ft) below ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8724211                         PUBLICATION DATE:  06/09/2003
Name:       BIG PINE KEY VIADUCT                              
            FL
NOAA Chart: 11445                           Latitude:   24° 40.2' N (  24.67000)
USGS Quad:  BIG PINE KEY                    Longitude:  81° 22.1' W ( -81.36830)


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


                         BENCH MARK STAMPING:  J 328 1970
                         DESIGNATION:          J 328

MONUMENTATION:           Bench Mark disk                       VM#:         8913
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AA0235
SETTING CLASSIFICATION:  Concrete sea wall                     OPUS PID:        
LATITUDE:   24° 40.2' N (  24.67000)          LONGITUDE:  81° 22.1' W ( -81.36830)


The bench mark is a disk set in the top of the SE corner of a concrete seawall,
located at the east end of the first canal north of U.S. Highway 1, 73.61 m
(241.5 ft) north of the centerline of U.S. Highway 1, 20.39 m (66.9 ft) south of
bench mark K 328 1970, 14 m (46 ft) west of the centerline of the gravel road
leading north, 0.43 m (1.4 ft) NW of the SE corner of the sea wall and dock, and
1 m (2 ft) below the level of the ground.

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

                                                                                
Station ID: 8724211                         PUBLICATION DATE:  06/09/2003
Name:       BIG PINE KEY VIADUCT                              
            FL
NOAA Chart: 11445                           Latitude:   24° 40.2' N (  24.67000)
USGS Quad:  BIG PINE KEY                    Longitude:  81° 22.1' W ( -81.36830)


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


                         BENCH MARK STAMPING:  K 328 1970
                         DESIGNATION:          K 328

MONUMENTATION:           Bench Mark disk                       VM#:         8914
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AA0233
SETTING CLASSIFICATION:  Concrete sea wall                     OPUS PID:        
LATITUDE:   24° 40.2' N (  24.67000)          LONGITUDE:  81° 22.1' W ( -81.36830)


The bench mark is a disk set in top of the NE corner of a concrete sea wall,
located at the east end of the first canal north of U.S. Highway 1, 94.00 m
(308.4 ft) north of the centerline of U.S. Highway 1, 20.39 m (66.9 ft) north of
bench mark J 328 1970, 15 m (48 ft) west of the centerline of the gravel road,
and level with the top of the sea wall.

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

                                                                                
Station ID: 8724211                         PUBLICATION DATE:  06/09/2003
Name:       BIG PINE KEY VIADUCT                              
            FL
NOAA Chart: 11445                           Latitude:   24° 40.2' N (  24.67000)
USGS Quad:  BIG PINE KEY                    Longitude:  81° 22.1' W ( -81.36830)


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


                         BENCH MARK STAMPING:  M 328 1970
                         DESIGNATION:          M 328

MONUMENTATION:           Bench Mark disk                       VM#:         8915
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  AA0226
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   24° 40.3' N (  24.67170)          LONGITUDE:  81° 22.1' W ( -81.36830)


The bench mark is a disk set in the top of a mass of outcropping bedrock,
located 0.2 km (0.1 mi) north along the gravel road from U.S. Highway 1, 10 m
(32 ft) east of the centerline of the gravel road, 5 m (16 ft) NE of the 5#
powerline pole from U.S. Highway 1, and level with the ground.

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

                                                                                
Station ID: 8724211                         PUBLICATION DATE:  06/09/2003
Name:       BIG PINE KEY VIADUCT                              
            FL
NOAA Chart: 11445                           Latitude:   24° 40.2' N (  24.67000)
USGS Quad:  BIG PINE KEY                    Longitude:  81° 22.1' W ( -81.36830)


                            T I D A L   D A T U M S 


Tidal datums at BIG PINE KEY VIADUCT based on:

     LENGTH OF SERIES:      1 YEAR
     TIME PERIOD:           January 1974 - December 1974
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8724580 KEY WEST


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

     HIGHEST OBSERVED WATER LEVEL (10/07/1974)         =  0.679
     North American Vertical Datum              NAVD88 =  0.377
     MEAN HIGHER HIGH WATER                     MHHW   =  0.334
     MEAN HIGH WATER                            MHW    =  0.264
     MEAN SEA LEVEL                             MSL    =  0.148
     MEAN TIDE LEVEL                            MTL    =  0.143
     MEAN LOW WATER                             MLW    =  0.023
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (02/10/1971)         = -0.373

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 1 1971                                   0.880    0.616
     J 328 1970                                  0.883    0.619
     K 328 1970                                  1.367    1.103
     M 328 1970                                  0.574    0.310


Foot Notes:

Bench mark M 328 1970 is based on one differential leveling connection and does
not meet the quality control standards of the NOS.  Therefore, caution should be
used when deriving elevations for this mark.

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

                                                                                
Station ID: 8724211                         PUBLICATION DATE:  06/09/2003
Name:       BIG PINE KEY VIADUCT                              
            FL
NOAA Chart: 11445                           Latitude:   24° 40.2' N (  24.67000)
USGS Quad:  BIG PINE KEY                    Longitude:  81° 22.1' W ( -81.36830)


                             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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Revised: 08/08/2018
NOAA / National Ocean Service
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