Bench Mark Sheet for 9014098, Fort Gratiot MI

Superseded Epoch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Small blue map location marker Unpublished bench mark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  7

                                                                                
Station ID: 9014098                         PUBLICATION DATE:  08/11/2017
Name:       FORT GRATIOT, ST. CLAIR RIVER                     
            MI
NOAA Chart: 14852                           Latitude:   43°  0.4' N (  43.00690)
USGS Quad:                                  Longitude:  82° 25.3' W ( -82.42250)


TO REACH THE NOS GAUGE HOUSE, IN PORT HURON, ST CLAIR COUNTY, MICHIGAN, FROM THE
INTERSECTION OF PINE GROVE AVE (M-24) AND GARFIELD ST, PROCEED EAST ON GARFIELD
ST FOR APPROX 0.85 MILE (1.37 KM) TO THE INTERSECTION WITH OMAR ST, THEN PROCEED
SOUTH ON OMAR ST FOR APPROX 0.05 MILE (0.08 KM) TO THE COUNTY PARKS & REC BACK
GATE ON THE EAST SIDE OF OMAR ST, THEN PROCEED THRU THE GATE TO THE NORTHEAST
CORNER OF AND ON THE ST. CLAIR COUNTY PARKS & REC "FORT GRATIOT" PROPERTY, TO
THE NOS WATER LEVEL GAUGING STATION.


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


                 PRIMARY BENCH MARK STAMPING:  RETAINING WALL
                         DESIGNATION:          901 4098 RETAINING WALL

MONUMENTATION:           Survey disk                           VM#:        13014
AGENCY:                  US Lake Survey                        IDB PID#:  OJ0009
SETTING CLASSIFICATION:  Wall                                  OPUS PID:        
LATITUDE:   43°  0.4' N (  43.00622)          LONGITUDE:  82° 25.3' W ( -82.42244)


The bench mark is a disk near the Fort Gratiot Lighthouse, set in top of the
South end of a U-shaped retaining wall around the lighthouse, 31.15 m (102.20
ft) SE of the NE corner of building number 3 on Coast Guard property, 3.07 m
(10.07 ft) SSE of the SW corner of small entrance house to lighthouse, 0.83 m
(2.72 ft) East of the West end of the retaining wall, 0.49 m (1.61 ft) above the
ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 9014098                         PUBLICATION DATE:  08/11/2017
Name:       FORT GRATIOT, ST. CLAIR RIVER                     
            MI
NOAA Chart: 14852                           Latitude:   43°  0.4' N (  43.00690)
USGS Quad:                                  Longitude:  82° 25.3' W ( -82.42250)


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


                         BENCH MARK STAMPING:  FORT
                         DESIGNATION:          901 4098 FORT

MONUMENTATION:           Survey disk                           VM#:        13015
AGENCY:                  Army Corp of Engineers                IDB PID#:  OJ0014
SETTING CLASSIFICATION:  Foundation                            OPUS PID:        
LATITUDE:   43°  0.4' N (  43.00669)          LONGITUDE:  82° 25.4' W ( -82.42253)


The bench mark is a disk set in the SW corner of the foundation of the National
Ocean Service gauge house which is at the NE corner of the property, 26.38 m
(86.55 ft) East of the NE corner of the USCG Auxiliary building, 0.37 m (1.21
ft) NNE of the SW corner of the foundation, 0.15 m (0.49 ft) WNW of the SW
corner of the gauge house, being highest point over cross at center of bronze
disc set into the concrete foundation.



                         BENCH MARK STAMPING:  LIGHT
                         DESIGNATION:          901 4098 LIGHT

MONUMENTATION:           Flange-encased Rod                    VM#:        13016
AGENCY:                  National Geodetic Survey              IDB PID#:  OJ0015
SETTING CLASSIFICATION:  Galvanized steel pipe in sleeve       OPUS PID:        
LATITUDE:   43°  0.4' N (  43.00636)          LONGITUDE:  82° 25.3' W ( -82.42247)


The bench mark is a rod 24.06 m (78.94 ft) NE of the most SE corner of building
number 3, 4.27 m (14.01 ft) WNW of a 3-inch pipe on the North face of the
lighthouse, 2.9 m (9.5 ft) South of the SW corner of the North end of a U-shaped
retaining wall around the lighthouse, being highest point on top of a stainless
steel plug of a 3/8-inch diameter steel pipe, 0.46 m (1.51 ft) below the ground
surface.  Note, mark is encased in a 5-inch PVC pipe with an aluminum access
cover stamped "Light".

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 9014098                         PUBLICATION DATE:  08/11/2017
Name:       FORT GRATIOT, ST. CLAIR RIVER                     
            MI
NOAA Chart: 14852                           Latitude:   43°  0.4' N (  43.00690)
USGS Quad:                                  Longitude:  82° 25.3' W ( -82.42250)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          901 4098 FORT GRATIOT LH

MONUMENTATION:           Bolt                                  VM#:        13017
AGENCY:                                                        IDB PID#:  OJ0010
SETTING CLASSIFICATION:  Foundation                            OPUS PID:        
LATITUDE:   43°  0.4' N (  43.00625)          LONGITUDE:  82° 25.4' W ( -82.42292)


The bench mark is a bolt set at the SE corner of building number 3 (red brick
dwelling), 21.7 m (71.2 ft) West of theSW corner of the lighthouse, 11.8 m (38.7
ft) East of the SW corner of building number 3, 10.4 m (34.1 ft) North of the NE
corner of resident building 2802, 0.67 m (2.20 ft) West of the most SE corner of
building number 3, 0.12 m (0.39 ft) below bottom of the water table, 0.67 m
(2.20 ft) above the sidewalk, being center of small hole in end of a copper bolt
set into the stone foundation, surrounded by the chiseled letters "USBM".

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 9014098                         PUBLICATION DATE:  08/11/2017
Name:       FORT GRATIOT, ST. CLAIR RIVER                     
            MI
NOAA Chart: 14852                           Latitude:   43°  0.4' N (  43.00690)
USGS Quad:                                  Longitude:  82° 25.3' W ( -82.42250)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          GARDEN

MONUMENTATION:           Bolt                                  VM#:        13018
AGENCY:                  National Geodetic Survey              IDB PID#:  OJ0013
SETTING CLASSIFICATION:                                        OPUS PID:        
LATITUDE:   43°  0.4' N (  43.00600)          LONGITUDE:  82° 25.4' W ( -82.42364)


The bench mark is a bolt set in the lawn about 56.9 m (186.7 ft) North of the NE
corner of the headquarters building, 49.2 m (161.4 ft) SSW of the SE corner of a
3 bay garage, 48.3 m (158.5 ft) West of the SW corner of a yellow brick house
near the lighthouse, 42.0 m (137.8 ft) North of the center of the entrance to
the Coast Guard station, 22.1 m (72.5 ft) NW of the North volleyball post, 19.0
m (62.3 ft) East of a cyclone fence at the intersection of the retaining wall,
18.4 m (60.4 ft) West of a 24 inch oak tree from its center, 15.4 m (50.5 ft)
South of a lone 24-inch maple tree, 14.8 m (48.6 ft) East of the NE corner of a
concrete retaining wall which is flush with the ground, 0.07 m (0.23 ft) below
the ground surface, being highest point on top of a brass bolt set into the top
of a 7-inch diameter concrete post with chiseled letters USBM.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 9014098                         PUBLICATION DATE:  08/11/2017
Name:       FORT GRATIOT, ST. CLAIR RIVER                     
            MI
NOAA Chart: 14852                           Latitude:   43°  0.4' N (  43.00690)
USGS Quad:                                  Longitude:  82° 25.3' W ( -82.42250)


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


                         BENCH MARK STAMPING:  COLD
                         DESIGNATION:          901 4098 COLD

MONUMENTATION:           Metal Rod                             VM#:        13019
AGENCY:                  National Geodetic Survey              IDB PID#:  OJ0012
SETTING CLASSIFICATION:  Metal rod driven into the ground      OPUS PID:        
LATITUDE:   43°  0.3' N (  43.00544)          LONGITUDE:  82° 25.4' W ( -82.42325)


The bench mark is a metal rod set on the East side of the headquarters building
which is a two story frame structure, 36.2 m (118.8 ft) SW of a fire hydrant,
26.0 m (85.3 ft) West of the center of the flag pole, 20.73 m (68.01 ft) South
of the centerline of the entrance driveway, 3.23 m (10.60 ft) South of the NE
corner of the porch, 1.75 m (5.74 ft) WNW of the NE corner of the bottom step,
0.36 m (1.18 ft) ESE of the face of the underpinning of the porch, just below
the canvas tarmac of rock garden, being the highest point of a 1-inch diameter
iron rod 4.42 m (14.50 ft) long, 0.01 m (0.03 ft) below ground surface, with a 5
inch PVC pipe and aluminum access cover flush to the gravel landscaping.





Foot Notes:

Above marks are published for informational purposes only.  Long term stability
has not been reviewed prior to publication.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 9014098                         PUBLICATION DATE:  08/11/2017
Name:       FORT GRATIOT, ST. CLAIR RIVER                     
            MI
NOAA Chart: 14852                           Latitude:   43°  0.4' N (  43.00690)
USGS Quad:                                  Longitude:  82° 25.3' W ( -82.42250)


                             D E F I N I T I O N S


The International Great Lakes Datum (IGLD) is the vertical height reference
datum used in the Great Lakes/St. Lawrence River System for engineering,
charting, channel dredging, navigation safety, power generation, and water 
resource management. It is a coordinated datum between the United States and
Canada that ensures both countries are using the same reference for projects
in the Great Lakes basin. The datum origin, or zero, is defined as Mean Sea 
Level at Pointe-au-Pere /Rimouski, Quebec, Canada at the mouth of the 
St. Lawrence River. IGLD requires updating approximately every 25-30 years 
to account for varying changes in the land surface elevations following the 
retreat of the glaciers during the last ice age, referred to as Glacial 
Isostatic Adjustment (GIA). The current IGLD 1985 was implemented in 1992.

IGLD 1985 uses dynamic heights as the vertical reference standard and lakes
station water level elevations are adjusted to provide a level geopotential
plane for lake level reference.

Dynamic height is the potential difference along the plumbline between the 
vertical datum and a point of interest divided by a constant value of 
gravity. In Canada and USA, the constant value of gravity is the 
"normal gravity" on the ellipsoid at latitude 45 (9.806199 ms-2). Dynamic 
heights have no geometric meaning. They are mainly used for the management 
of water in large lakes, rivers and channels. The surface of a lake has a 
constant dynamic height if undisturbed by currents, winds, atmospheric 
pressure, etc.

The Hydraulic Corrector (HC) is the difference in the long term water level 
mean between Subordinate and Master station. The difference (HC) is 
subtracted algebraically at the subordinate gauge referencing the same 
elevation as the master station. Thus all water levels on a given lake can 
be referenced to the same lakes LWD/Chart Datum reference elevation.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 9014098                         PUBLICATION DATE:  08/11/2017
Name:       FORT GRATIOT, ST. CLAIR RIVER                     
            MI
NOAA Chart: 14852                           Latitude:   43°  0.4' N (  43.00690)
USGS Quad:                                  Longitude:  82° 25.3' W ( -82.42250)


                             D E F I N I T I O N S


A Master Stations is the control point for determining water level 
elevations on a particular lake of the Great Lakes.   Since water surfaces
of the Great Lakes are considered to be at geopotential equal, all Mean 
Water Level (MWL) values for stations on a particular lake should have the 
same dynamic height.  Therefore, all subordinate water level station MWL 
values are adjusted to match the dynamic water level elevation of the Master
Station through the use of a hydraulic corrector.  In the establishment of 
International Great Lakes Datum (1985) the connecting waterways station 
dynamic elevations were calculated through the use of a linear regression 
while constraining the end points of the regression with the dynamic 
elevations of the corresponding master station above and below the 
connecting channel.

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 toNAVD88 are available from NGS through the World Wide 
Web at National Geodetic Survey.

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/.


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