Superseded Bench Mark Sheet for 8447368, Great Hill MA

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  06/13/1988
Station ID: 8447368                                SUPERCEDED DATE:   04/21/2003
Name:       GREAT HILL, GREAT HILL ESTATE, BUZZARDS BAY       
            MASSACHUSETTS
NOAA Chart: 13236                                  Latitude:         41° 42.7' N
USGS Quad:  ONSET                                  Longitude:        70° 42.9' W


To reach the tidal bench marks from Wareham, proceed SSW on U.S. Highway 6 to
Sippican Neck, then SE along Sippican Neck to Great Hill, then east to Great
Hill Estates, then south from the Great Hill Estates entrance gate for 0.6 mile
(1.0 km) to the concrete and stone pier.  The bench marks are along the beach of
the Great Hill Estates.  The tide gage and staff were on the NE end of the Great
Hill Estates pier.


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


                 PRIMARY BENCH MARK STAMPING:  7368 A 1977

MONUMENTATION:           Survey Disk                               VM#:     2034
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Pier


The bench mark is set flush in the surface of the north end of the Great Hill
Estates pier, 16 feet (5 m) SE of the NW wall of the pier, and 16 feet (5 m) SW
of the NE wall of the pier.



                         BENCH MARK STAMPING:  NO 1 1931

MONUMENTATION:           Survey Disk                               VM#:     2032
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Granite Wall


The bench mark is set flush in the top of the SE wall of the Great Hill Estates
pier, at the intersection of the pier wall and the concrete sidewalk leading the
the bathhouse, south of Bench Mark 7368 A 1977, and level with the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  06/13/1988
Station ID: 8447368                                SUPERCEDED DATE:   04/21/2003
Name:       GREAT HILL, GREAT HILL ESTATE, BUZZARDS BAY       
            MASSACHUSETTS
NOAA Chart: 13236                                  Latitude:         41° 42.7' N
USGS Quad:  ONSET                                  Longitude:        70° 42.9' W


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


                         BENCH MARK STAMPING:  NO 2 1949

MONUMENTATION:           Survey Disk                               VM#:     2033
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Granite Boulder


The bench mark is set flush in the top of a large granite boulder located south
along the beach from the Great Hill Estates pier, 165 feet (50 m) NE of the
Great Hill Estates flagpole, 150 feet (46 m) NNW of Bench Mark 7368 C 1977, 5
feet (2 m) west of the approximate high water line, and 5 feet (2 m) above the
level of the ground.



                         BENCH MARK STAMPING:  7368 B 1977

MONUMENTATION:           Survey Disk                               VM#:     2035
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Foundation


The bench mark is set flush in a 1 foot (0.3 m) wide abutment in the north
corner of the Great Hill Estates bathhouse foundation, 300 feet (91 m) south of
the Great Hill Estates pier, 3 feet (1 m) NE of the north entrance to the
bathhouse, and 4 feet (1 m) below the bathhouse floor.



                         BENCH MARK STAMPING:  7368 C 1977

MONUMENTATION:           Survey Disk                               VM#:     2036
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Boulder


The bench mark is set in the top peak of a 8 x 6 foot (2 x 2 m) boulder in the
sea wall south of the Great Hill Estates pier, 150 feet (46 m) SSE of Bench Mark
NO 2 1949, and 120 feet (37 m) east of the Great Hill Estates flagpole.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  06/13/1988
Station ID: 8447368                                SUPERCEDED DATE:   04/21/2003
Name:       GREAT HILL, GREAT HILL ESTATE, BUZZARDS BAY       
            MASSACHUSETTS
NOAA Chart: 13236                                  Latitude:         41° 42.7' N
USGS Quad:  ONSET                                  Longitude:        70° 42.9' W


                            T I D A L   D A T U M S 


Tidal datums at GREAT HILL, GREAT HILL ESTATE, BUZZARDS BAY based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           AUGUST - OCTOBER 1977
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8452660 NEWPORT, RI


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

     HIGHEST OBSERVED WATER LEVEL (11/11/1977)         =   7.42
     MEAN HIGHER HIGH WATER                     MHHW   =   4.50
     MEAN HIGH WATER                            MHW    =   4.20
     MEAN TIDE LEVEL                            MTL    =   2.19
     MEAN LOW WATER                             MLW    =   0.17
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (08/28/1977)         =  -0.85



Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     7368 A 1977                                 6.48      2.28
     NO 1 1931                                   6.83      2.63
     NO 2 1949                                   9.02      4.82
     7368 B 1977                                10.25      6.05
     7368 C 1977                                15.15     10.95


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

                                                   PUBLICATION DATE:  06/13/1988
Station ID: 8447368                                SUPERCEDED DATE:   04/21/2003
Name:       GREAT HILL, GREAT HILL ESTATE, BUZZARDS BAY       
            MASSACHUSETTS
NOAA Chart: 13236                                  Latitude:         41° 42.7' N
USGS Quad:  ONSET                                  Longitude:        70° 42.9' 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.

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