U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 8440466 PUBLICATION DATE: 03/24/2006
Name: NEWBURYPORT, MERRIMACK RIVER
MA
NOAA Chart: 13282 Latitude: 42° 48.9' N ( 42.81500)
USGS Quad: NEWBURYPORT EAST Longitude: 70° 52.4' W ( -70.87330)
To reach the tidal bench marks from U.S. Highway 1 in Newburyport, proceed off
the downtown exit to Merrimac Street, then proceed SE on Merrimac Street for 0.6
km (0.4 mi) to Water Street, then proceed SE on Water Street for 0.3 km (0.2 mi)
to the Newburyport U.S. Coast Guard Station. The bench marks are on the Coast
Guard grounds, along Water Street, and along Merrimac Street NE of the Coast
Guard station. The tide gage and staff were on the NW boat launch pier at the
station.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 0466 A 1989
DESIGNATION: 844 0466 A TIDAL
MONUMENTATION: Tidal Station disk VM#: 1461
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete sewer cap OPUS PID:
LATITUDE: 42° 48.7' N ( 42.81170) LONGITUDE: 70° 51.9' W ( -70.86500)
The primary bench mark is a disk set in the south corner of a concrete sewer cap
located along the NE side of the entrance drive to the Coast Guard station, 30 m
(100 ft) WSW of the south corner of the station garage, 11.00 m (36.1 ft) NNW of
the pipe fence along the SW side of the entrance drive, 2.80 m (9.2 ft) SSW of
the north corner of the concrete cap, and 0.37 m (1.2 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8440466 PUBLICATION DATE: 03/24/2006
Name: NEWBURYPORT, MERRIMACK RIVER
MA
NOAA Chart: 13282 Latitude: 42° 48.9' N ( 42.81500)
USGS Quad: NEWBURYPORT EAST Longitude: 70° 52.4' W ( -70.87330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: F-1 1923 ELEV 26.634 FT
DESIGNATION: F 1
MONUMENTATION: Bench Mark disk VM#: 1462
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#: MY0157
SETTING CLASSIFICATION: Building wall OPUS PID:
LATITUDE: 42° 48.7' N ( 42.81170) LONGITUDE: 70° 52.4' W ( -70.87330)
The bench mark is a disk set vertically in the south face of the SW corner of
the Police Station and District Court located on Green Street, 16 m (54 ft) west
of the west curb of Green Street, 12.62 m (41.4 ft) ENE of the NW corner of City
Hall, 0.46 m (1.5 ft) east of the SW corner of the building, 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 6
Station ID: 8440466 PUBLICATION DATE: 03/24/2006
Name: NEWBURYPORT, MERRIMACK RIVER
MA
NOAA Chart: 13282 Latitude: 42° 48.9' N ( 42.81500)
USGS Quad: NEWBURYPORT EAST Longitude: 70° 52.4' W ( -70.87330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: COAST GUARD 1974
DESIGNATION: COAST GUARD
MONUMENTATION: Survey disk VM#: 1463
AGENCY: US Army Corp of Engineers (COE) IDB PID#:
SETTING CLASSIFICATION: Concrete pier deck OPUS PID#: BBCG18
LATITUDE: 42° 48.7' N ( 42.81170) LONGITUDE: 70° 51.9' W ( -70.86500)
The bench mark is a disk set in the NE end of the concrete deck of the NW boat
launch pier located at the Coast Guard station, 21.15 m (69.4 ft) NNE of the
south corner of the pier, 3.78 m (12.4 ft) WSW of the NE edge of the pier, 1.04
m (3.4 ft) NW of the SE edge of the pier.
BENCH MARK STAMPING: 0466 B 1989
MONUMENTATION: Tidal Station disk VM#: 1464
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete ramp OPUS PID:
LATITUDE: 42° 48.7' N ( 42.81170) LONGITUDE: 70° 51.9' W ( -70.86500)
The bench mark is a disk set in the north end of the concrete ramp of the second
drive-in bay of the easternmost building in Atkinsons Lumber Yard, 25 m (82 ft)
NNE of the centerline of Water Street, 12.98 m (42.6 ft) SSE of the east corner
of the Bennett & Mason Building at 45 Water Street, 0.55 m (1.8 ft) WNW of the
west wall of the easternmost Atkinson Lumber Yard building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8440466 PUBLICATION DATE: 03/24/2006
Name: NEWBURYPORT, MERRIMACK RIVER
MA
NOAA Chart: 13282 Latitude: 42° 48.9' N ( 42.81500)
USGS Quad: NEWBURYPORT EAST Longitude: 70° 52.4' W ( -70.87330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0466 C 1989
MONUMENTATION: Tidal Station disk VM#: 1465
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete bulkhead cap OPUS PID:
LATITUDE: 42° 48.7' N ( 42.81170) LONGITUDE: 70° 51.9' W ( -70.86500)
The bench mark is a disk set in the concrete bulkhead cap of a wooden pier
located on the south shore of Merrimack River, NE of a parking lot NNW of the
Maritime Museum, in a gap of the wooden bench along the north edge of the pier,
5.49 m (18.0 ft) north of the center of the end of a ramp leading from the
parking lot to the pier, 5.46 m (17.9 ft) east of a light pole on the pier, 0.18
m (0.6 ft) SSW of the north edge of the cap, and 0.12 m (0.4 ft) below the pier
deck.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8440466 PUBLICATION DATE: 03/24/2006
Name: NEWBURYPORT, MERRIMACK RIVER
MA
NOAA Chart: 13282 Latitude: 42° 48.9' N ( 42.81500)
USGS Quad: NEWBURYPORT EAST Longitude: 70° 52.4' W ( -70.87330)
T I D A L D A T U M S
Tidal datums at NEWBURYPORT, MERRIMACK RIVER based on:
LENGTH OF SERIES: 12 MONTHS
TIME PERIOD: June 1989 - May 1990
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8418150 PORTLAND, CASCO BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (05/24/1990) = 3.290
MEAN HIGHER HIGH WATER MHHW = 2.671
MEAN HIGH WATER MHW = 2.538
MEAN TIDE LEVEL MTL = 1.305
MEAN SEA LEVEL MSL = 1.304
MEAN LOW WATER MLW = 0.072
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (12/12/1989) = -0.453
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
0466 A 1989 4.787 2.249
F-1 1923 ELEV 26.634 FT 9.162 6.624
COAST GUARD 1974 4.057 1.519
0466 B 1989 4.551 2.013
0466 C 1989 3.794 1.256
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8440466 PUBLICATION DATE: 03/24/2006
Name: NEWBURYPORT, MERRIMACK RIVER
MA
NOAA Chart: 13282 Latitude: 42° 48.9' N ( 42.81500)
USGS Quad: NEWBURYPORT EAST Longitude: 70° 52.4' W ( -70.87330)
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.