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Bench Mark Sheet for 8442645, SALEM, SALEM HARBOR 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  6

                                                                                
Station ID: 8442645                         PUBLICATION DATE:  02/05/2004
Name:       SALEM, SALEM HARBOR                               
            MA
NOAA Chart: 13276                           Latitude:   42° 31.4' N (  42.52330)
USGS Quad:  SALEM                           Longitude:  70° 52.6' W ( -70.87670)


To reach the tidal bench marks from the U.S. Custom House on the corner of Derby
and Orange Streets in Salem, proceed NE on Derby Street for 0.8 km (0.5 mi) to
Fort Avenue, proceed NE on Fort Avenue for about 91 m (300 ft) to the entrance
of the New England Electric Salem Harbor Station. The bench marks are on the
harbor station property. The tide gauge and staff were on the fishing pier
located on the SE section of the harbor station property.


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


                 PRIMARY BENCH MARK STAMPING:  2645 A 1992
                         DESIGNATION:          844 2645 A

MONUMENTATION:           Tidal Station disk                    VM#:        11832
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete abutment                     OPUS PID:        
LATITUDE:   42° 31.4' N (  42.52330)          LONGITUDE:  70° 52.6' W ( -70.87670)


The primary bench mark is a disk set in the east end of the concrete abutment
located on the east side of the discharge channel where it meets the bay, 14.48
m (47.5 ft) north of the NE corner of the foot of the pier, 2.35 m (7.7 ft) WNW
of the east corner of a chain link fence, and 0.06 m (0.2 ft) SW of the NE
corner of the abutment.

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

                                                                                
Station ID: 8442645                         PUBLICATION DATE:  02/05/2004
Name:       SALEM, SALEM HARBOR                               
            MA
NOAA Chart: 13276                           Latitude:   42° 31.4' N (  42.52330)
USGS Quad:  SALEM                           Longitude:  70° 52.6' W ( -70.87670)


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


                         BENCH MARK STAMPING:  2645 B 1992
                         DESIGNATION:          844 2645 B

MONUMENTATION:           Tidal Station disk                    VM#:        11833
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete pier                         OPUS PID:        
LATITUDE:   42° 31.4' N (  42.52330)          LONGITUDE:  70° 52.6' W ( -70.87670)


The bench mark is a disk set in the southernmost corner of the concrete pier for
a steel grate walkway located over the discharge channel, 0.2 km (0.1 mi) SW of
the start of the gravel road leading to the fishing pier, 1.01 m (3.3 ft) SE of
the NW edge of the pier, 0.94 m (3.1 ft) SW of the centerline of the steel
grating, and 0.76 m (2.5 ft) below grade.



                         BENCH MARK STAMPING:  2645 C 1992
                         DESIGNATION:          844 2645 C

MONUMENTATION:           Tidal Station disk                    VM#:        11834
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete flagpole base                OPUS PID#: BBDN24
LATITUDE:   42° 31.4' N (  42.52330)          LONGITUDE:  70° 52.6' W ( -70.87670)


The bench mark is a disk set in the SE quadrant of the circular concrete
flagpole base at the start of the gravel road leading to the fishing pier, 31 m
(101 ft) WNW of the NW corner of the glass enclosed entrance to the Salem Harbor
Station offices, 3.60 m (11.8 ft) west of the south end of the steel rail just
east of the flagpole, and 0.52 m (1.7 ft) SE of the flagpole.

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

                                                                                
Station ID: 8442645                         PUBLICATION DATE:  02/05/2004
Name:       SALEM, SALEM HARBOR                               
            MA
NOAA Chart: 13276                           Latitude:   42° 31.4' N (  42.52330)
USGS Quad:  SALEM                           Longitude:  70° 52.6' W ( -70.87670)


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


                         BENCH MARK STAMPING:  2645 D 1992
                         DESIGNATION:          844 2645 D

MONUMENTATION:           Tidal Station disk                    VM#:        11835
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete footing                      OPUS PID:        
LATITUDE:   42° 31.4' N (  42.52330)          LONGITUDE:  70° 52.6' W ( -70.87670)


The bench mark is a disk set in the NW corner of the northernmost concrete
footing for the air filtration building, 9.97 m (32.7 ft) SE of the west yellow
concrete guardpost at the entrance to the vehicle passage under the building,
6.68 m (21.9 ft) south of the NW corner of the chainlink fence surrounding the
generators, 0.37 m (1.2 ft) WNW of the NW corner of a steel H-pile, and 0.24 m
(0.8 ft) above grade.



                         BENCH MARK STAMPING:  2645 E 1992
                         DESIGNATION:          844 2645 E

MONUMENTATION:           Tidal Station disk                    VM#:        11836
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete retaining wall               OPUS PID:        
LATITUDE:   42° 31.4' N (  42.52330)          LONGITUDE:  70° 52.6' W ( -70.87670)


The bench mark is a disk set in the NE corner of the concrete retaining wall for
surge basin #6, 19.75 m (64.8 ft) SSW of the yellow concrete post just inside
the main entrance gate, 20.42 m (67.0 ft) WSW of the bottom step of the stairs
to the guard house, 0.85 m (2.8 ft) SSE from the NE retaining wall corner, and
0.85 m (2.8 ft) above grade.

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

                                                                                
Station ID: 8442645                         PUBLICATION DATE:  02/05/2004
Name:       SALEM, SALEM HARBOR                               
            MA
NOAA Chart: 13276                           Latitude:   42° 31.4' N (  42.52330)
USGS Quad:  SALEM                           Longitude:  70° 52.6' W ( -70.87670)


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


                         BENCH MARK STAMPING:  BM 2
                         DESIGNATION:          844 2645 BM 2

MONUMENTATION:           Bench Mark disk                       VM#:        11837
AGENCY:                  South Essex Sewer District (S.E.S.D.) IDB PID#:        
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   40° 31.4' N (  40.52330)          LONGITUDE:  70° 52.6' W ( -70.87670)


The bench mark is a disk set in a concrete monument on the Salem Harbor Station
property located near the corner of Webb and Derby Streets, 10 m (34 ft) SW of
the centerline of Webb Street, 2.10 m (6.9 ft) SW of the SE corner of a large
granite post, 0.49 m (1.6 ft) SE of a wire fence.



                         BENCH MARK STAMPING:  NO 19 1916
                         DESIGNATION:          844 2645 TIDAL 19

MONUMENTATION:           Tidal Station disk                    VM#:        11838
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Wall                                  OPUS PID:        
LATITUDE:   42° 31.4' N (  42.52330)          LONGITUDE:  70° 52.6' W ( -70.87670)


The bench mark is a disk set vertically in the wall located at the SW corner of
the U.S. Custom House, 18.23 m (59.8 ft) NNW of the centerline of Derby Street,
8.75 m (28.7 ft) ENE of the centerline of Orange Street, 0.15 m (0.5 ft) ENE of
the SW corner of the building, and 0.15 m (0.5 ft) above the sidewalk.

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

                                                                                
Station ID: 8442645                         PUBLICATION DATE:  02/05/2004
Name:       SALEM, SALEM HARBOR                               
            MA
NOAA Chart: 13276                           Latitude:   42° 31.4' N (  42.52330)
USGS Quad:  SALEM                           Longitude:  70° 52.6' W ( -70.87670)


                            T I D A L   D A T U M S 


Tidal datums at SALEM, SALEM HARBOR based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           September 1992 - September 1992
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8443970 BOSTON, BOSTON HARBOR


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.956
     MEAN HIGH WATER                            MHW    =  2.822
     MEAN SEA LEVEL                             MSL    =  1.477
     MEAN TIDE LEVEL                            MTL    =  1.461
     MEAN LOW WATER                             MLW    =  0.100
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     2645 A 1992                                 3.916    1.094
     2645 B 1992                                 4.571    1.749
     2645 C 1992                                 4.853    2.031
     2645 D 1992                                 4.841    2.019
     2645 E 1992                                 5.747    2.925
     BM 2                                        4.623    1.801
     NO 19 1916                                  5.481    2.659


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

                                                                                
Station ID: 8442645                         PUBLICATION DATE:  02/05/2004
Name:       SALEM, SALEM HARBOR                               
            MA
NOAA Chart: 13276                           Latitude:   42° 31.4' N (  42.52330)
USGS Quad:  SALEM                           Longitude:  70° 52.6' W ( -70.87670)


                             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 8442645 SALEM, SALEM HARBOR, MA

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