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Bench Mark Sheet for 8440273, SALISBURY POINT, MERRIMACK RIVER 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 8440273                         PUBLICATION DATE:  09/17/2003
Name:       SALISBURY POINT                                   
            MA
NOAA Chart: 13282                           Latitude:   42° 50.3' N (  42.83830)
USGS Quad:  NEWBURYPORT WEST                Longitude:  70° 54.5' W ( -70.90830)


To reach the bench marks from the Amesbury exit (#55) of Interstate Highway 495,
proceed east on State Road 110 for 1.8 km (1.1 mi) to Merrill Street, then SW on
Merrill Street for 1.3 km (0.8 mi) to the swing bridge over Merrimack River. 
The bench marks are near the bridge and Interstate Highway 495.  The tide gage
and staff were on the east bridge fender.


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


                 PRIMARY BENCH MARK STAMPING:  0273 A 1989
                         DESIGNATION:          844 0273 A

MONUMENTATION:           Tidal Station disk                    VM#:         1443
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:   Bedrock                              OPUS PID:        
LATITUDE:   42° 50.3' N (  42.83830)          LONGITUDE:  70° 54.5' W ( -70.90830)


The primary bench mark is a disk set flush in an outcropping of bedrock, 32 m
(106 ft) NE of power pole #83/1 on the north side of Old Merrill Street, 9 m (29
ft) west of power pole #2, and 8 m (26 ft) NNW of the centerline of Old Merrill
Street.

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

                                                                                
Station ID: 8440273                         PUBLICATION DATE:  09/17/2003
Name:       SALISBURY POINT                                   
            MA
NOAA Chart: 13282                           Latitude:   42° 50.3' N (  42.83830)
USGS Quad:  NEWBURYPORT WEST                Longitude:  70° 54.5' W ( -70.90830)


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


                         BENCH MARK STAMPING:  4869
                         DESIGNATION:          844 0273 4869

MONUMENTATION:           Survey disk                           VM#:         1444
AGENCY:                  Massachusetts Geodetic Survey (MAGS)  IDB PID#:        
SETTING CLASSIFICATION:  Concrete sidewalk                     OPUS PID:        
LATITUDE:   42° 50.3' N (  42.83830)          LONGITUDE:  70° 54.5' W ( -70.90830)


The bench mark is a disk set flush in the concrete sidewalk at the NE end of the
Interstate Highway 95 bridge (Whittier Memorial Bridge) over Merrimack River,
0.85 m (2.8 ft) east of the center of a manhole cover in the sidewalk, 0.67 m
(2.2 ft) SW of the north end of the sidewalk, and 0.43 m (1.4 ft) NW of the face
of the granite retaining wall.



                         BENCH MARK STAMPING:   
                         DESIGNATION:          844 0273 NO STAMPING 1

MONUMENTATION:           Survey disk                           VM#:         1445
AGENCY:                  Massachusetts DPW (MADPW)             IDB PID#:        
SETTING CLASSIFICATION:  Concrete abutment                     OPUS PID:        
LATITUDE:   42° 50.3' N (  42.83830)          LONGITUDE:  70° 54.5' W ( -70.90830)


The bench mark is a disk set flush in the NE concrete abutment of the Main
Street bridge over Merrimack River, 36 m (119 ft) south of the centerline of Old
Merrill Street, 5 m (16 ft) east of the centerline of Main Street, and 4 m (13
ft) north of a steel power pole with electric meter on the east side of the
bridge.

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

                                                                                
Station ID: 8440273                         PUBLICATION DATE:  09/17/2003
Name:       SALISBURY POINT                                   
            MA
NOAA Chart: 13282                           Latitude:   42° 50.3' N (  42.83830)
USGS Quad:  NEWBURYPORT WEST                Longitude:  70° 54.5' W ( -70.90830)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          844 0273 NO STAMPING 2

MONUMENTATION:           Survey disk                           VM#:         1446
AGENCY:                  Massachusetts DPW (MADPW)             IDB PID#:        
SETTING CLASSIFICATION:  Concrete abutment                     OPUS PID#: BBBJ42
LATITUDE:   42° 50.3' N (  42.83830)          LONGITUDE:  70° 54.5' W ( -70.90830)


The bench mark is a disk set flush in the SW concrete abutment of the Main
Street bridge over the Merrimack River, 4.60 m (15.1 ft) WSW of the centerline
of Main Street, 4.08 m (13.4 ft) NNE of the north corner of the bridge tender's
house, and 0.21 m (0.7 ft) NW of the SE edge of the abutment.



                         BENCH MARK STAMPING:   
                         DESIGNATION:          844 0273 NO STAMPING 3

MONUMENTATION:           Rivet                                 VM#:         1447
AGENCY:                  Unknown                               IDB PID#:        
SETTING CLASSIFICATION:  Concrete wing wall                    OPUS PID:        
LATITUDE:   42° 50.3' N (  42.83830)          LONGITUDE:  70° 54.5' W ( -70.90830)


The bench mark is set flush in the SE concrete wingwall of the Essex-Merrimack
suspension bridge on the south side of Deer Island, 53.98 m (177.1 ft) north of
the NW corner of the residence at #3 Spofford Street, and 7.07 m (23.2 ft) east
of the centerline of Spofford Street.

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

                                                                                
Station ID: 8440273                         PUBLICATION DATE:  09/17/2003
Name:       SALISBURY POINT                                   
            MA
NOAA Chart: 13282                           Latitude:   42° 50.3' N (  42.83830)
USGS Quad:  NEWBURYPORT WEST                Longitude:  70° 54.5' W ( -70.90830)


                            T I D A L   D A T U M S 


Tidal datums at SALISBURY POINT based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           July 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   =  2.525
     MEAN HIGH WATER                            MHW    =  2.387
     MEAN SEA LEVEL                             MSL    =  1.227
     MEAN TIDE LEVEL                            MTL    =  1.223
     MEAN LOW WATER                             MLW    =  0.058
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0273 A 1989                                 7.502    5.115
     4869                                       20.585   18.198
     844 0273 NO STAMPING 1                      8.490    6.103
     844 0273 NO STAMPING 2                      8.360    5.973
     844 0273 NO STAMPING 3                     10.490    8.103


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

                                                                                
Station ID: 8440273                         PUBLICATION DATE:  09/17/2003
Name:       SALISBURY POINT                                   
            MA
NOAA Chart: 13282                           Latitude:   42° 50.3' N (  42.83830)
USGS Quad:  NEWBURYPORT WEST                Longitude:  70° 54.5' W ( -70.90830)


                             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 8440273 SALISBURY POINT, MERRIMACK RIVER, MA

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