Bench Mark Sheet for 8724238, MUNSON KEY 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 8724238                         PUBLICATION DATE:  03/09/2004
Name:       MUNSON KEY                                        
            FL
NOAA Chart: 11445                           Latitude:   24° 37.4' N (  24.62330)
USGS Quad:  LOGGERHEAD KEY                  Longitude:  81° 24.2' W ( -81.40330)


To reach the tidal bench marks from the east end of the U.S. Highway 1 bridge
between Little Torch Key and Big Pine Key, proceed SW by boat 5.8 km (3.1 nm) to
the west end of Munson Island, Newfound Harbor Keys.  The bench marks are
located on the grounds of the Newfound Harbor Yacht Club.  The tide gage and
staff were located at the inside bend of the pier at the yacht club.


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


                 PRIMARY BENCH MARK STAMPING:  NO 1 1937
                         DESIGNATION:          872 4238 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:         6847
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete block                        OPUS PID:        
LATITUDE:   24° 37.4' N (  24.62330)          LONGITUDE:  81° 24.2' W ( -81.40330)


The primary bench mark is a disk set flush in the SW corner of a concrete block
located on the grounds of the Newfound Harbor Yacht Club on Munson Key near the
pier, 47.24 m (155.0 ft) SW of bench mark 4238 F 1984, 9.75 m (32.0 ft) SE of
the SE corner of the pier, 6.49 m (21.3 ft) NNE of the northwest side of the
house, 2.99 m (9.8 ft) NW of the NW side of the house.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8724238                         PUBLICATION DATE:  03/09/2004
Name:       MUNSON KEY                                        
            FL
NOAA Chart: 11445                           Latitude:   24° 37.4' N (  24.62330)
USGS Quad:  LOGGERHEAD KEY                  Longitude:  81° 24.2' W ( -81.40330)


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


                         BENCH MARK STAMPING:  NO 2 1937
                         DESIGNATION:          872 4238 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:         6848
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete step                         OPUS PID:        
LATITUDE:   24° 37.4' N (  24.62330)          LONGITUDE:  81° 24.2' W ( -81.40330)


The bench mark is a disk set flush in the second concrete step of the NE steps
to the storm house (NE of the main building), and 15.21 m (49.9 ft) south of
bench mark 4238 F 1984.



                         BENCH MARK STAMPING:  NO 5 1973
                         DESIGNATION:          872 4238 TIDAL 5

MONUMENTATION:           Tidal Station disk                    VM#:         6849
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete step                         OPUS PID:        
LATITUDE:   24° 37.4' N (  24.62330)          LONGITUDE:  81° 24.2' W ( -81.40330)


The bench mark is a disk set flush in the bottom concrete step located at the NW
side of the storm house, 6.25 m (20.5 ft) east of the NE corner of the main
house, 5.64 m (18.5 ft) SW of the north corner of the storm house, and 2.83 m
(9.3 ft) NE of the west corner of the storm house.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8724238                         PUBLICATION DATE:  03/09/2004
Name:       MUNSON KEY                                        
            FL
NOAA Chart: 11445                           Latitude:   24° 37.4' N (  24.62330)
USGS Quad:  LOGGERHEAD KEY                  Longitude:  81° 24.2' W ( -81.40330)


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


                         BENCH MARK STAMPING:  NO 6 1973
                         DESIGNATION:          872 4238 TIDAL 6

MONUMENTATION:           Tidal Station disk                    VM#:         6850
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   24° 37.4' N (  24.62330)          LONGITUDE:  81° 24.2' W ( -81.40330)


The bench mark is a disk set flush in the concrete foundation located inside the
doorway of the generator building, 13 m (42 ft) ENE of bench mark NO  2 1937,
0.73 m (2.4 ft) NE of the SW side of the generator building, and 0.18 m (0.6 ft)
SE of the NW side of the generator building.



                         BENCH MARK STAMPING:  4238 F 1984
                         DESIGNATION:          872 4238 TIDAL F

MONUMENTATION:           Tidal Station disk                    VM#:         6851
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   24° 37.4' N (  24.62330)          LONGITUDE:  81° 24.2' W ( -81.40330)


The bench mark is a disk set flush in a 0.30 m (1.0 ft) diameter concrete
monument with a 4-inch PVC pipe imbedded in the center, 18 m (59 ft) NNE of
bench mark NO 5 1973, 13.93 m (45.7 ft) NW of the west corner of the generator
building, 1.52 m (5.0 ft) west of the south corner of an outhouse, and 1.43 m
(4.7 ft) SW of the west corner of an outhouse.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8724238                         PUBLICATION DATE:  03/09/2004
Name:       MUNSON KEY                                        
            FL
NOAA Chart: 11445                           Latitude:   24° 37.4' N (  24.62330)
USGS Quad:  LOGGERHEAD KEY                  Longitude:  81° 24.2' W ( -81.40330)


                            T I D A L   D A T U M S 


Tidal datums at MUNSON KEY based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           November 1973 - December 1973
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8724580 KEY WEST


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.528
     MEAN HIGH WATER                            MHW    =  0.452
     MEAN SEA LEVEL                             MSL    =  0.252
     MEAN TIDE LEVEL                            MTL    =  0.250
     MEAN LOW WATER                             MLW    =  0.047
     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 1 1937                                   2.090    1.638
     NO 2 1937                                   2.179    1.727
     NO 5 1973                                   2.029    1.577
     NO 6 1973                                   1.497    1.045
     4238 F 1984                                 1.505    1.053


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

                                                                                
Station ID: 8724238                         PUBLICATION DATE:  03/09/2004
Name:       MUNSON KEY                                        
            FL
NOAA Chart: 11445                           Latitude:   24° 37.4' N (  24.62330)
USGS Quad:  LOGGERHEAD KEY                  Longitude:  81° 24.2' W ( -81.40330)


                             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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