Bench Mark Sheet for 8724107, MISSOURI-OHIO CHANNEL 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8724107                         PUBLICATION DATE:  03/09/2004
Name:       MISSOURI-OHIO CHANNEL                             
            FL
NOAA Chart: 11445                           Latitude:   24° 40.4' N (  24.67330)
USGS Quad:  SEVENMILE BRIDGE                Longitude:  81° 14.6' W ( -81.24330)


To reach the tidal bench marks from the post office at Marathon, proceed 17.4 km
(10.8 mi) SW on U.S. Highway 1 to the SW end of the bridge over Missouri-Ohio
Channel, at the eastern side of Ohio Key.  The bench marks are located near the
west end of the old bridge which is now used as a fishing pier, at the east and
west end of the new bridge, and at the east end of the bridge over Ohio-Bahia
Channel.  The tide gage and staff were located offshore of the SW concrete wing
wall of the old bridge.


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


                 PRIMARY BENCH MARK STAMPING:  NO 4 1975
                         DESIGNATION:          872 4107 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:         6352
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA0950
SETTING CLASSIFICATION:  Concrete wing wall                    OPUS PID:        
LATITUDE:   24° 40.4' N (  24.67330)          LONGITUDE:  81° 14.6' W ( -81.24330)


The primary bench mark is a disk set flush in the top of the SE concrete wing
wall at the SW end of the old bridge over Missouri-Ohio Channel, 7.53 m (24.7
ft) south of bench mark NO 5 1975, 5 m (18 ft) SE of the centerline of the old
bridge, 1 m (4 ft) south of the bridge abutment, and 1 m (3 ft) below the level
of the old bridge.

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

                                                                                
Station ID: 8724107                         PUBLICATION DATE:  03/09/2004
Name:       MISSOURI-OHIO CHANNEL                             
            FL
NOAA Chart: 11445                           Latitude:   24° 40.4' N (  24.67330)
USGS Quad:  SEVENMILE BRIDGE                Longitude:  81° 14.6' W ( -81.24330)


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


                         BENCH MARK STAMPING:  4107 E
                         DESIGNATION:          872 4107 E TIDAL FLDT

MONUMENTATION:           Bench Mark disk                       VM#:         6348
AGENCY:                  Florida Department of Transportation
                         (FLDT)                                IDB PID#:  AA0949
SETTING CLASSIFICATION:  Concrete bridge guardrail             OPUS PID:        
LATITUDE:   24° 40.4' N (  24.67330)          LONGITUDE:  81° 14.6' W ( -81.24330)


The bench mark is a disk set in the top of the concrete guardrail at the SW end
of the new bridge over Missouri-Ohio Channel, 7.19 m (23.6 ft) SE of the
centerline of U.S. Highway 1, 3.20 m (10.5 ft) NE of the SW end of the
guardrail, 0.18 m (0.6 ft) SW of the abutment, and 1 m (3 ft) above highway
level.



                         BENCH MARK STAMPING:  4107 F
                         DESIGNATION:          872 4107 F TIDAL FLDT

MONUMENTATION:           Bench Mark disk                       VM#:         6349
AGENCY:                  Florida Department of Transportation
                         (FLDT)                                IDB PID#:  AA0952
SETTING CLASSIFICATION:  Concrete bridge guardrail             OPUS PID:        
LATITUDE:   24° 40.6' N (  24.67670)          LONGITUDE:  81° 14.4' W ( -81.24000)


The bench mark is a disk set in the top of the concrete guardrail at the NE end
of the bridge, 7.04 m (23.1 ft) NW of the centerline of U.S. Highway 1, 3.20 m
(10.5 ft) SW of the NE end of the guardrail, 0.18 m (0.6 ft) NE of the abutment,
and 1 m (3 ft) above highway level.

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

                                                                                
Station ID: 8724107                         PUBLICATION DATE:  03/09/2004
Name:       MISSOURI-OHIO CHANNEL                             
            FL
NOAA Chart: 11445                           Latitude:   24° 40.4' N (  24.67330)
USGS Quad:  SEVENMILE BRIDGE                Longitude:  81° 14.6' W ( -81.24330)


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


                         BENCH MARK STAMPING:  C 70 RESET 1936
                         DESIGNATION:          C 70 RESET 1936

MONUMENTATION:           Bench Mark disk                       VM#:         6350
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  AA0275
SETTING CLASSIFICATION:  Concrete wing wall                    OPUS PID:        
LATITUDE:   24° 40.3' N (  24.67170)          LONGITUDE:  81° 14.9' W ( -81.24830)


The bench mark is a disk set in the top of the SE concrete wing wall at the NE
end of the bridge #17,  4 m (12 ft) SE of the centerline of the old highway, and
1 m (2 ft) below the level of the old highway.



                         BENCH MARK STAMPING:  NO 3 1975
                         DESIGNATION:          872 4107 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:         6351
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete wing wall                    OPUS PID:        
LATITUDE:   24° 40.6' N (  24.67670)          LONGITUDE:  81° 14.6' W ( -81.24330)


The bench mark is a disk set flush in the top of the SW concrete wing wall at
the west end of the old bridge over Missouri-Ohio Channel, 11 m (36 ft) south of
bench mark NO 4 1975. 

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

                                                                                
Station ID: 8724107                         PUBLICATION DATE:  03/09/2004
Name:       MISSOURI-OHIO CHANNEL                             
            FL
NOAA Chart: 11445                           Latitude:   24° 40.4' N (  24.67330)
USGS Quad:  SEVENMILE BRIDGE                Longitude:  81° 14.6' W ( -81.24330)


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


                         BENCH MARK STAMPING:  NO 5 1975
                         DESIGNATION:          872 4107 TIDAL 5

MONUMENTATION:           Bench Mark disk                       VM#:         6353
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  AA0951
SETTING CLASSIFICATION:  Bridge abutment                       OPUS PID:        
LATITUDE:   24° 40.4' N (  24.67330)          LONGITUDE:  81° 14.6' W ( -81.24330)


The bench mark is a disk set flush in the top of the bridge abutment at the SW
end of the old bridge over Missouri-Ohio Channel, 7.53 m (24.7 ft) north of
bench mark NO 4 1975, 3.26 m (10.7 ft) NW of the centerline of the old bridge,
and 0.15 m (0.5 ft) NE of the SW end of the bridge.

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

                                                                                
Station ID: 8724107                         PUBLICATION DATE:  03/09/2004
Name:       MISSOURI-OHIO CHANNEL                             
            FL
NOAA Chart: 11445                           Latitude:   24° 40.4' N (  24.67330)
USGS Quad:  SEVENMILE BRIDGE                Longitude:  81° 14.6' W ( -81.24330)


                            T I D A L   D A T U M S 


Tidal datums at MISSOURI-OHIO CHANNEL based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           March 1975 - March 1975
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8724138 BAHIA HONDA KEY


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

     North American Vertical Datum              NAVD88 =  0.473
     MEAN HIGHER HIGH WATER                     MHHW   =  0.428
     MEAN HIGH WATER                            MHW    =  0.356
     MEAN SEA LEVEL                             MSL    =  0.204
     MEAN TIDE LEVEL                            MTL    =  0.198
     MEAN LOW WATER                             MLW    =  0.040
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 4 1975                                   3.244    2.888
     4107 E                                      5.566    5.210
     4107 F                                      5.555    5.199
     C 70 RESET 1936                             3.305    2.949
     NO 3 1975                                   1.358    1.002
     NO 5 1975                                   4.132    3.776


Foot Notes:

Bench marks 4107 E and 4107 F are based on one differential leveling connection
and do not meet the quality control standards of the NOS. Therefore, caution
should be used when deriving elevations for these marks.

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

                                                                                
Station ID: 8724107                         PUBLICATION DATE:  03/09/2004
Name:       MISSOURI-OHIO CHANNEL                             
            FL
NOAA Chart: 11445                           Latitude:   24° 40.4' N (  24.67330)
USGS Quad:  SEVENMILE BRIDGE                Longitude:  81° 14.6' W ( -81.24330)


                             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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