U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 6
Station ID: 8447712 PUBLICATION DATE: 05/20/2004
Name: NEW BEDFORD, CLARKS POINT
MA
NOAA Chart: 13230 Latitude: 41° 35.6' N ( 41.59330)
USGS Quad: NEW BEDFORD SOUTH Longitude: 70° 54.0' W ( -70.90000)
To reach the tidal bench marks from New Bedford, proceed south on the peninsula
east of Clark's Cove to Fort Tabor and the New Bedford Waste Water Treatment
Plant at Clark's Point. The bench marks are located in the vicinity of the fort
and the treatment plant. The tide gage and staff were located on pilings along
the breakwater near the NE corner of the treatment plant.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 8447712 PUBLICATION DATE: 05/20/2004
Name: NEW BEDFORD, CLARKS POINT
MA
NOAA Chart: 13230 Latitude: 41° 35.6' N ( 41.59330)
USGS Quad: NEW BEDFORD SOUTH Longitude: 70° 54.0' W ( -70.90000)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7 1931
DESIGNATION: TIDAL 7 STA 88
MONUMENTATION: Tidal Station disk VM#: 2072
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#: LW0072
SETTING CLASSIFICATION: Concrete step OPUS PID#: LW0072
LATITUDE: 41° 35.6' N ( 41.59330) LONGITUDE: 70° 54.1' W ( -70.90170)
The primary bench mark is a disk set in the north corner of the second concrete
step at Battery Wolcott No. 2, between Fort Tabor and the shoreline, 43 m (140
ft) SE of the south end of a stone and concrete pier leading north to boat
docks.
BENCH MARK STAMPING: 7712 E 1976
DESIGNATION: 844 7712 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 2073
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Light pole base OPUS PID:
LATITUDE: 41° 35.6' N ( 41.59330) LONGITUDE: 70° 54.0' W ( -70.90000)
The bench mark is a disk set flush in the base of the SE light pole of the water
tank area at the New Bedford Waste Water Treatment Plant, 11.80 m (38.7 ft) SE
of the SE concrete water tank, and 0.3 m (1 ft) south of a steel guardrail.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 8447712 PUBLICATION DATE: 05/20/2004
Name: NEW BEDFORD, CLARKS POINT
MA
NOAA Chart: 13230 Latitude: 41° 35.6' N ( 41.59330)
USGS Quad: NEW BEDFORD SOUTH Longitude: 70° 54.0' W ( -70.90000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7712 F 1976
DESIGNATION: 844 7712 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 2074
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Light pole base OPUS PID:
LATITUDE: 41° 35.6' N ( 41.59330) LONGITUDE: 70° 54.0' W ( -70.90000)
The bench mark is a disk set flush in the base of the NE light pole of the water
tank area at the New Bedford Waste Water Treatment Center, 94.37 m (309.6 ft)
north of bench mark 7712 E 1976, 32 m (105 ft) east of a 2 m (6 ft) high chain
link fence forming the western border of the plant, and 11.64 m (38.2 ft) NE of
the NE concrete water tank.
BENCH MARK STAMPING: 7712 G 1976
DESIGNATION: 844 7712 G TIDAL
MONUMENTATION: Tidal Station disk VM#: 2075
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete step OPUS PID#: BBDZ02
LATITUDE: 41° 35.6' N ( 41.59330) LONGITUDE: 70° 54.0' W ( -70.90000)
The bench mark is a disk set flush in the top of the SW set of steps at Battery
Wolcott No. 2 adjacent to Fort Tabor, 24 m (80 ft) NE of a gravel road
separating the battery from Fort Tabor, and 19 m (63 ft) SE of the NE corner of
the Fort Tabor parking lot.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 8447712 PUBLICATION DATE: 05/20/2004
Name: NEW BEDFORD, CLARKS POINT
MA
NOAA Chart: 13230 Latitude: 41° 35.6' N ( 41.59330)
USGS Quad: NEW BEDFORD SOUTH Longitude: 70° 54.0' W ( -70.90000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7712 H 1976
DESIGNATION: 844 7712 H TIDAL
MONUMENTATION: Tidal Station disk VM#: 2076
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete walkway OPUS PID:
LATITUDE: 41° 35.6' N ( 41.59330) LONGITUDE: 70° 54.0' W ( -70.90000)
The bench mark is a disk set flush in the top of the concrete walkway at the
entrance to the stone and concrete pier near Fort Tabor, 128 m (420 ft) east of
the main road leading to Fort Tabor, 26.00 m (85.3 ft) east of the east corner
of a concrete garage.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 8447712 PUBLICATION DATE: 05/20/2004
Name: NEW BEDFORD, CLARKS POINT
MA
NOAA Chart: 13230 Latitude: 41° 35.6' N ( 41.59330)
USGS Quad: NEW BEDFORD SOUTH Longitude: 70° 54.0' W ( -70.90000)
T I D A L D A T U M S
Tidal datums at NEW BEDFORD, CLARKS POINT based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: June 1976 - October 1976
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8452660 NEWPORT, NARRAGANSETT BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.206
MEAN HIGH WATER MHW = 1.130
MEAN TIDE LEVEL MTL = 0.587
MEAN SEA LEVEL MSL = 0.510
MEAN LOW WATER MLW = 0.044
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7 1931 2.730 1.600
7712 E 1976 5.086 3.956
7712 F 1976 5.235 4.105
7712 G 1976 2.513 1.383
7712 H 1976 2.487 1.357
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 8447712 PUBLICATION DATE: 05/20/2004
Name: NEW BEDFORD, CLARKS POINT
MA
NOAA Chart: 13230 Latitude: 41° 35.6' N ( 41.59330)
USGS Quad: NEW BEDFORD SOUTH Longitude: 70° 54.0' W ( -70.90000)
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.