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Bench Mark Sheet for 8440452, PLUM ISLAND, MERRIMACK RIVER ENTRANCE MA

Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8440452                         PUBLICATION DATE:  09/16/2003
Name:       PLUM ISLAND, MERRIMACK  RIVER ENTRANCE            
            MA
NOAA Chart: 13282                           Latitude:   42° 49.0' N (  42.81670)
USGS Quad:  NEWBURYPORT EAST                Longitude:  70° 49.2' W ( -70.82000)


To reach the tidal bench marks from the U.S. Coast Guard Station on Water Street
in Newburyport, proceed SW on Water Street for 4.8 km (3.0 mi) to Northern
Boulevard on Plum Island, then turn left and proceed north on Northern Boulevard
(Point Road) for 2.6 km (1.6 mi) to the abandoned Coast Guard Auxiliary Station
at Plum Island Point. The bench marks are near the large parking lot at the
point and near Newburyport Light. The tide station was on the NE abandoned Coast
Guard pier.


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


                 PRIMARY BENCH MARK STAMPING:  TBM NO 1 1953
                         DESIGNATION:          844 0452 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:         1456
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   ' °deg (0)          LONGITUDE:  ' °deg (0)


The primary bench mark is a disk set in the NW corner of the concrete foundation
for the wooden stairs at the south end of the U.S. Coast Guard Auxiliary
Station, 29.63 m (97.2 ft) east of power pole #18824, 24.23 m (79.5 ft) NNE of a
power pole in the SW area of the Auxiliary Station compound, 16.25 m (53.3 ft)
NE of the north corner of the easternmost of two red pump houses, 8.38 m (27.5
ft) SW of the east corner of the Auxiliary Station building, 0.55 m (1.8 ft) SE
of the west corner of the foundation, and 0.09 m (0.3 ft) above ground level.

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

                                                                                
Station ID: 8440452                         PUBLICATION DATE:  09/16/2003
Name:       PLUM ISLAND, MERRIMACK  RIVER ENTRANCE            
            MA
NOAA Chart: 13282                           Latitude:   42° 49.0' N (  42.81670)
USGS Quad:  NEWBURYPORT EAST                Longitude:  70° 49.2' W ( -70.82000)


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


                         BENCH MARK STAMPING:  TBM NO 2 1953
                         DESIGNATION:          844 0452 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:         1457
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation for Flagpole      OPUS PID#: BBBJ41
LATITUDE:   42° 49.0' N (  42.81670)          LONGITUDE:  70° 49.2' W ( -70.82000)


The bench mark is a disk set in the concrete base of a former flag pole on the
grounds of the headquarters for Parker River National Wildlife Refuge, 25.39 m
(83.3 ft) SW of power pole #31, 24.48 m (80.3 ft) NW of a flag pole, 17.62 m
(57.8 ft) NE of the NE corner of the light keeper's house, 8.17 m (26.8 ft)
south of a 1.07 m (3.5 ft) diameter concrete well casing, 8 m (26 ft) NNE of the
northernmost of two bird house poles, and 0.21 m (0.7 ft) below ground level.



                         BENCH MARK STAMPING:  0452 A 1989
                         DESIGNATION:          844 0452 A

MONUMENTATION:           Tidal Station disk                    VM#:         1458
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete loading dock                 OPUS PID:        
LATITUDE:   ' °deg (0)          LONGITUDE:  ' °deg (0)


The bench mark is a disk set in the south corner of the concrete loading dock of
the Division of Marine Fisheries Shellfish Purification Plant, 27.46 m (90.1 ft)
WSW of power pole #A579, 11.06 m (36.3 ft) SSW of the east corner of the loading
dock, 0.49 m (1.6 ft) north of the south corner of the loading dock, and 0.52 m
(1.7 ft) above ground level.

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

                                                                                
Station ID: 8440452                         PUBLICATION DATE:  09/16/2003
Name:       PLUM ISLAND, MERRIMACK  RIVER ENTRANCE            
            MA
NOAA Chart: 13282                           Latitude:   42° 49.0' N (  42.81670)
USGS Quad:  NEWBURYPORT EAST                Longitude:  70° 49.2' W ( -70.82000)


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


                         BENCH MARK STAMPING:  0452 B 1989
                         DESIGNATION:          844 0452 B

MONUMENTATION:           Tidal Station disk                    VM#:         1459
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   ' °deg (0)          LONGITUDE:  ' °deg (0)


The bench mark is a disk set in the west corner of a concrete slab NW of
Merrimack Fire Department Plum Island Station, 63 m (206 ft) NW of the NW corner
of the fire station, 17.53 m (57.5 ft) NNE of power pole #188-18, 9.97 m (32.7
ft) WSW of the NW corner of Plum Island Comfort Station, 5.64 m (18.5 ft) SSW of
the north edge of the slab, and 0.15 m (0.5 ft) above ground level.



                         BENCH MARK STAMPING:  0452 C 1989
                         DESIGNATION:          844 0452 C

MONUMENTATION:           Tidal Station disk                    VM#:         1460
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID:        
LATITUDE:   ' °deg (0)          LONGITUDE:  ' °deg (0)


The bench mark is a disk set in the south corner of the concrete foundation for
the Parker River National Wildlife Refuge headquarters radio tower, 34 m (111
ft) south of the headquarters' flag pole, 20.03 m (65.7 ft) NE of the north
corner of a cinderblock storage shed SW of the headquarters building, 1.37 m
(4.5 ft) SSE of the west corner of the building, and 0.21 m (0.7 ft) above
ground level.

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

                                                                                
Station ID: 8440452                         PUBLICATION DATE:  09/16/2003
Name:       PLUM ISLAND, MERRIMACK  RIVER ENTRANCE            
            MA
NOAA Chart: 13282                           Latitude:   42° 49.0' N (  42.81670)
USGS Quad:  NEWBURYPORT EAST                Longitude:  70° 49.2' W ( -70.82000)


                            T I D A L   D A T U M S 


Tidal datums at PLUM ISLAND, MERRIMACK  RIVER ENTRANCE based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           June 1989 - September 1989
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8440466 NEWBURYPORT, MERRIMACK RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.654
     MEAN HIGH WATER                            MHW    =  2.529
     MEAN TIDE LEVEL                            MTL    =  1.310
     MEAN SEA LEVEL                             MSL    =  1.308
     MEAN LOW WATER                             MLW    =  0.091
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     TBM NO 1 1953                               4.256    1.727
     TBM NO 2 1953                               4.183    1.654
     0452 A 1989                                 3.844    1.315
     0452 B 1989                                 3.432    0.903
     0452 C 1989                                 4.843    2.314


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

                                                                                
Station ID: 8440452                         PUBLICATION DATE:  09/16/2003
Name:       PLUM ISLAND, MERRIMACK  RIVER ENTRANCE            
            MA
NOAA Chart: 13282                           Latitude:   42° 49.0' N (  42.81670)
USGS Quad:  NEWBURYPORT EAST                Longitude:  70° 49.2' W ( -70.82000)


                             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 8440452 PLUM ISLAND, MERRIMACK RIVER ENTRANCE, MA

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services