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Bench Mark Sheet for 8451301, THE GLEN,SAKONNET RIVER RI

Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 8451301                         PUBLICATION DATE:  05/20/2004
Name:       THE GLEN,SAKONNET RIVER                           
            RI
NOAA Chart: 13221                           Latitude:   41° 33.5' N (  41.55830)
USGS Quad:  TIVERTON                        Longitude:  71° 14.2' W ( -71.23670)


To reach the tidal bench marks from Middletown, Rhode Island, travel north 8 km
(5 mi) on South Main Street (State Route 138) to Glen Road, turn right (east)
onto Glen Road, proceed to Frank Coelho Drive, and take Frank Coelho Drive south
until it ends.  The bench marks are located along the shoreline, east of the end
of Frank Coelho Drive.  The tide gage was located on the west side of the pier,
and the staff was mounted on the north side of the pier.


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


                 PRIMARY BENCH MARK STAMPING:  1301 A 1977
                         DESIGNATION:          845 1301 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2138
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Granite seawall                       OPUS PID:        
LATITUDE:   41° 33.5' N (  41.55830)          LONGITUDE:  71° 14.2' W ( -71.23670)


The primary bench mark is a disk set flush in the granite portion of the seawall
north of the concrete entry to the wharf, 8.29 m (27.2 ft) NE (60  magnetic) of
the SE corner of the house, 6.86 m (22.5 ft) NNW (340  magnetic) of bench mark
1301 B 1977, and 6.86 m (22.5 ft) SE (140  magnetic) of the NW corner of the
house.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                                                
Station ID: 8451301                         PUBLICATION DATE:  05/20/2004
Name:       THE GLEN,SAKONNET RIVER                           
            RI
NOAA Chart: 13221                           Latitude:   41° 33.5' N (  41.55830)
USGS Quad:  TIVERTON                        Longitude:  71° 14.2' W ( -71.23670)


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


                         BENCH MARK STAMPING:  1301 B 1977
                         DESIGNATION:          845 1301 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2139
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete seawall                      OPUS PID:        
LATITUDE:   41° 33.5' N (  41.55830)          LONGITUDE:  71° 14.2' W ( -71.23670)


The bench mark is a disk set flush in the northernmost corner of the concrete
entry to the wharf, 13.69 m (44.9 ft) SE of the NW corner of the house and 7.59
m (24.9 ft) NW (340  magnetic) of bench mark 1301 C 1977, 6.86 m (22.5 ft) SSE
(160  magnetic) of bench mark 1301 A 1977.



                         BENCH MARK STAMPING:  1301 C 1977
                         DESIGNATION:          845 1301 C TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2140
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Concrete seawall                      OPUS PID:        
LATITUDE:   41° 33.5' N (  41.55830)          LONGITUDE:  71° 14.2' W ( -71.23670)


The bench mark is a disk set flush in the base of the concrete entry at the
junction of the north end of the rock seawall and the SW corner of the wharf,
19.17 m (69.2 ft) SE (130  magnetic) from the NE corner of the house and 17.74 m
(58.2 ft)  NNE (15  magnetic) of bench mark 1301 D 1977, 7.59 m (24.9 ft) SE of
bench mark 1301 B 1977.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                                                
Station ID: 8451301                         PUBLICATION DATE:  05/20/2004
Name:       THE GLEN,SAKONNET RIVER                           
            RI
NOAA Chart: 13221                           Latitude:   41° 33.5' N (  41.55830)
USGS Quad:  TIVERTON                        Longitude:  71° 14.2' W ( -71.23670)


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


                         BENCH MARK STAMPING:  1301 D 1977
                         DESIGNATION:          845 1301 D TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2141
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock seawall                          OPUS PID:        
LATITUDE:   41° 33.5' N (  41.55830)          LONGITUDE:  71° 14.2' W ( -71.23670)


The bench mark is a disk set flush in the granite portion of the rock seawall
south of the wharf, 22.10 m (72.5 ft) SSE (168  magnetic) of the SE corner of
the house, 16.03 m (52.6 ft) SSW (210  magnetic) of bench mark 1301 C 1977, and
11.43 m (37.5 ft) NNE (18  magnetic) of bench mark 1301 E 1977.



                         BENCH MARK STAMPING:  1301 E 1977
                         DESIGNATION:          845 1301 E TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         2142
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock seawall                          OPUS PID:        
LATITUDE:   41° 33.5' N (  41.55830)          LONGITUDE:  71° 14.2' W ( -71.23670)


The bench mark is a disk set flush in the granite portion of the rock seawall
south of the wharf, 32 m (105 ft) south (180  magnetic) of the SE corner of the
house, and 27 m (87 ft) south of the south end of the pier, and 11.43 m (37.5
ft) SSW of bench mark 1301 D 1977.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                                                
Station ID: 8451301                         PUBLICATION DATE:  05/20/2004
Name:       THE GLEN,SAKONNET RIVER                           
            RI
NOAA Chart: 13221                           Latitude:   41° 33.5' N (  41.55830)
USGS Quad:  TIVERTON                        Longitude:  71° 14.2' W ( -71.23670)


                            T I D A L   D A T U M S 


Tidal datums at THE GLEN,SAKONNET RIVER based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           October 1977
     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   =  1.168
     MEAN HIGH WATER                            MHW    =  1.080
     MEAN TIDE LEVEL                            MTL    =  0.562
     MEAN SEA LEVEL                             MSL    =  0.523
     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

     1301 A 1977                                 2.300    1.220
     1301 B 1977                                 2.437    1.357
     1301 C 1977                                 2.558    1.478
     1301 D 1977                                 2.285    1.205
     1301 E 1977                                 2.388    1.308


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

                                                                                
Station ID: 8451301                         PUBLICATION DATE:  05/20/2004
Name:       THE GLEN,SAKONNET RIVER                           
            RI
NOAA Chart: 13221                           Latitude:   41° 33.5' N (  41.55830)
USGS Quad:  TIVERTON                        Longitude:  71° 14.2' W ( -71.23670)


                             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 8451301 THE GLEN,SAKONNET RIVER, RI

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