U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
PUBLICATION DATE: 04/05/1990
Station ID: 8414612 SUPERCEDED DATE: 04/21/2003
Name: BANGOR, PENOBSCOT RIVER
MAINE
NOAA Chart: 13309 Latitude: 44° 47.8' N
USGS Quad: BANGOR Longitude: 68° 46.2' W
To reach the tidal bench marks from the intersection of Front Street and the
U.S. Highway 1A bridge on the west side of Penobscot River, proceed south on
Front Street. The bench marks are along Front and Railroad Streets. The tide
gage and staff were just north of the bridge.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 3 1970
MONUMENTATION: Survey Disk VM#: 1847
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Base
The bench mark is set flush in an abandoned concrete signal base on the north
side of Railroad Street, 11.8 feet (3.6 m) west of the west rail, and NE of the
NE corner of the brick control tower.
BENCH MARK STAMPING: NO 2 1970
MONUMENTATION: Survey Disk VM#: 1846
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Retaining Wall
The bench mark is set flush in a concrete retaining wall on the north side of
Railroad Street, 7.5 feet (2.3 m) above the railroad control tower parking lot,
and 1.0 foot (0.3 m) below the awning of the building.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
PUBLICATION DATE: 04/05/1990
Station ID: 8414612 SUPERCEDED DATE: 04/21/2003
Name: BANGOR, PENOBSCOT RIVER
MAINE
NOAA Chart: 13309 Latitude: 44° 47.8' N
USGS Quad: BANGOR Longitude: 68° 46.2' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4612 4 1984
MONUMENTATION: Survey Disk VM#: 1848
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set flush in a concrete monument on the east side of Front
Street, 43.5 feet (13.3 m) NE of a fire hydrant, 38 feet (12 m) south of a power
pole at a driveway to an oil company, 21.5 feet (6.6 m) east of the centerline
of Front Street, and 17.5 feet (5.3 m) west of a 10-foot (3 m) high wall
surrounding some fuel storage tanks.
BENCH MARK STAMPING: 4612 5 1984
MONUMENTATION: Survey Disk VM#: 1849
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Monument
The bench mark is set flush in a concrete monument at the intersection of May
and Front Streets, 36 feet (11 m) west of the railroad crossing signal on the
east side of the tracks, 10.5 feet (3.2 m) south of a power pole, 5 feet (2 m)
north of the centerline of May Street, and 4.5 feet (1.4 m) SE of the railroad
crossing signal on the west side of the tracks.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
PUBLICATION DATE: 04/05/1990
Station ID: 8414612 SUPERCEDED DATE: 04/21/2003
Name: BANGOR, PENOBSCOT RIVER
MAINE
NOAA Chart: 13309 Latitude: 44° 47.8' N
USGS Quad: BANGOR Longitude: 68° 46.2' W
T I D A L D A T U M S
Tidal datums at BANGOR, PENOBSCOT RIVER based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: JULY-SEPTEMBER 1984
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION: 8415490 ROCKLAND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (06/04/1984) = 18.36
MEAN HIGHER HIGH WATER MHHW = 14.10
MEAN HIGH WATER MHW = 13.52
MEAN TIDE LEVEL MTL = 6.89
MEAN LOW WATER MLW = 0.26
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (09/26/1984) = -3.21
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
NO 3 1970 24.67 11.15
NO 2 1970 32.34 18.82
4612 4 1984 24.05 10.53
4612 5 1984 26.85 13.33
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
PUBLICATION DATE: 04/05/1990
Station ID: 8414612 SUPERCEDED DATE: 04/21/2003
Name: BANGOR, PENOBSCOT RIVER
MAINE
NOAA Chart: 13309 Latitude: 44° 47.8' N
USGS Quad: BANGOR Longitude: 68° 46.2' W
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 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.