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Bench Mark Sheet for 8511907, Greenport NY

Superseded Epoch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Small blue map location marker Unpublished bench mark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  6

                                                                                
Station ID: 8511907                                PUBLICATION DATE:  11/06/2014
Name:       GREENPORT, GREENPORT HARBOR                       
            NY
NOAA Chart: 12358                                  Latitude:         41°  6.1' N
USGS Quad:  GREENPORT                              Longitude:        72° 21.7' W


To reach the station from route 48 at the intersection with main road route 25,
turn onto main rd/route 25 and proceed south 1.5 km (0.9 mi) to the intersection
with front street, turn right and proceed west 0.25 km (0.15 mi) to the parking
lot on the left for the greenport us post office at 131 front street, turn into
the parking lot and continue on foot south 0.1 km (0.1 mi) into mitchell park
and marina and the tide station at the nw corner of the marina.  The bench marks
are in mitchell park, near the long island railroad train station, an along the
streets of greenport.


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


                 PRIMARY BENCH MARK STAMPING:  1907 B 2014
                         DESIGNATION:          851 1907 B

MONUMENTATION:           Flange-encased Rod                        VM#:    21023
AGENCY:                  National Ocean Service                    PID:         
SETTING CLASSIFICATION:  Stainless steel rod in sleeve


The primary bench mark is a flange encased rod set in the grass below the wooden
boardwalk, 14.03 m (46.0 ft) NW of a storm drain, 8.70 m (28.5 ft) NE of the E
side of the wood dock, 5.10 m (16.7 ft) WSW of the center of the lowest step in
the stone stairs leading to the gravel path, 4.32 m (14.2 ft) ESE of the
boardwalk and 2.95 m (9.7 ft) S of a light pole.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 8511907                                PUBLICATION DATE:  11/06/2014
Name:       GREENPORT, GREENPORT HARBOR                       
            NY
NOAA Chart: 12358                                  Latitude:         41°  6.1' N
USGS Quad:  GREENPORT                              Longitude:        72° 21.7' W


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


                         BENCH MARK STAMPING:  1907 A 2014
                         DESIGNATION:          851 1907 A

MONUMENTATION:           Flange-encased Rod                        VM#:    21024
AGENCY:                  National Ocean Service                    PID:         
SETTING CLASSIFICATION:  Stainless steel rod in sleeve


The bench mark is a flange encased rod set in the grass lawn, 20.01 m (65.6 ft)
NNW  of the inside face of the wood seawall, 16.03 m (52.6 ft) NE of the center
of the entrance door to the camera obscura, 14.40 m (47.2 ft) SE of the SE
corner of the restroom building and 14.15 m (46.4 ft) SW of the NW corner of the
harbor masters building.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 8511907                                PUBLICATION DATE:  11/06/2014
Name:       GREENPORT, GREENPORT HARBOR                       
            NY
NOAA Chart: 12358                                  Latitude:         41°  6.1' N
USGS Quad:  GREENPORT                              Longitude:        72° 21.7' W


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


                         BENCH MARK STAMPING:  TIDAL 4 STA II 29
                         DESIGNATION:          TIDAL 4 STA II 29

MONUMENTATION:           Stone Monument                            VM#:    21025
AGENCY:                  Unknown                                   PID#:  LX0243
SETTING CLASSIFICATION:  Stone post set into the sidewalk


The bench mark is a stone post set in the sidewalk, 15.59 m (51.1 ft) NNE of a
power pole with metal tag nyt12, 9.31 m (30.5 ft) SSW of the SW corner of the
house porch at 84 central street, 8.29 m (27.2 ft) NNE of the manhole cover near
the center of the street intersection and 2.87 m (9.4 ft) NW of the stop sign on
the N side of central avenue.



                         BENCH MARK STAMPING:  1907 C 2014
                         DESIGNATION:          851 1907 C

MONUMENTATION:           Bench Mark disk                           VM#:    21026
AGENCY:                  National Ocean Service                    PID:         
SETTING CLASSIFICATION:  Concrete pad.


The bench mark is a disk set in the concrete slab for the bicycle storage
lockers, 12.77 m (41.9 ft) WSW of the base of the decorative ship anchor, 10.94
m (35.9 ft) S of the S most rail of the pair of long island railroad tracks,
5.35 m (17.6 ft) S of the SW corner of a rectangular storm drain, 4.98 m (16.3
ft) NE of the NE corner of the bus shelter and 0.13 m (0.4 ft) ENE of the E side
of the bicycle storage lockers.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 8511907                                PUBLICATION DATE:  11/06/2014
Name:       GREENPORT, GREENPORT HARBOR                       
            NY
NOAA Chart: 12358                                  Latitude:         41°  6.1' N
USGS Quad:  GREENPORT                              Longitude:        72° 21.7' W


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


                         BENCH MARK STAMPING:  Z 325
                         DESIGNATION:          Z 325 1943

MONUMENTATION:           Bench Mark disk                           VM#:    21027
AGENCY:                  U.S. Coastal Geodetic Survey              PID#:  LX0237
SETTING CLASSIFICATION:  Set in a culvert


The bench mark is a disk set in the top of a concrete headwall for a culvert on
the N side of route 25, 38.74 m (127.1 ft) ENE of a fire hydrant, 31.08 m (102.0
ft) WSW of the centerline of a private driveway, 26.00 m (85.3 ft) WSW of a
power pole with no tag, 6.65 m (21.8 ft) NNW of the road centerline, 4.08 m
(13.4 ft) ENE of a power pole with no tag, 0.2 m (0.7 ft) S of the N end of the
culvert, 0.69 m (2.3 ft) above the ground and 0.25 m (0.8 ft) below the asphalt
road.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 8511907                                PUBLICATION DATE:  11/06/2014
Name:       GREENPORT, GREENPORT HARBOR                       
            NY
NOAA Chart: 12358                                  Latitude:         41°  6.1' N
USGS Quad:  GREENPORT                              Longitude:        72° 21.7' W


                            T I D A L   D A T U M S 


Tidal datums at GREENPORT, GREENPORT HARBOR based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           May 2014 - July 2014
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8461490 NEW LONDON, THAMES RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.885
     MEAN HIGH WATER                            MHW    =  0.799
     MEAN SEA LEVEL                             MSL    =  0.441
     MEAN TIDE LEVEL                            MTL    =  0.426
     MEAN LOW WATER                             MLW    =  0.054
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1907 B 2014                                 2.273    1.474
     1907 A 2014                                 1.951    1.152
     TIDAL 4 STA II 29                           3.540    2.741
     1907 C 2014                                 2.595    1.796
     Z 325                                       4.133    3.334


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  6

                                                                                
Station ID: 8511907                                PUBLICATION DATE:  11/06/2014
Name:       GREENPORT, GREENPORT HARBOR                       
            NY
NOAA Chart: 12358                                  Latitude:         41°  6.1' N
USGS Quad:  GREENPORT                              Longitude:        72° 21.7' 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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Products available at 8511907 Greenport, NY

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services