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Bench Mark Sheet for 9465283, NE SIDE SUMMIT ISLAND, TOGIAK BAY A AK

Superseded Epoch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Small blue map location marker Unpublished bench mark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: 9465283                         PUBLICATION DATE:  03/19/2019
Name:       NE SIDE SUMMIT ISLAND, TOGIAK BAY A               
            AK
NOAA Chart:                                 Latitude:   58° 50.8' N (  58.84670)
USGS Quad:                                  Longitude: 160° 12.6' W (-160.21001)





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


                 PRIMARY BENCH MARK STAMPING:  5283 D 1986
                         DESIGNATION:          946 5283 D 1986

MONUMENTATION:           Survey disk                           VM#:        15351
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   58° 50.8' N (  58.84670)          LONGITUDE: 160° 12.6' W (-160.21000)


The primary bench mark is a disk which lies in bedrock 0.91 m (3.0 ft) east of
the bluff about 0.61 m (2.0 ft) above the gravel, in a cove on the NE side of
Summit Island, 1.83 m (6.0 ft) north of a rock wall that extends from a grassy
bluff, 200 m (656 ft) NW (350  magnetic) from bench mark 5283 C 1986 and 35.66 m
(117.0 ft) from bench mark 5283 E 1986.



                         BENCH MARK STAMPING:  5283 A 1986
                         DESIGNATION:          946 5283 A 1986

MONUMENTATION:           Survey disk                           VM#:        15348
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  North face of a rocky point           OPUS PID:        
LATITUDE:   58° 50.8' N (  58.84670)          LONGITUDE: 160° 12.6' W (-160.21000)


The bench mark is a disk located in a cove on the NE side of Summit Island, on
the north face of a rocky point which is north of the point at the southern
limit of the cove, 0.15 m (0.5 ft) above the gravel by the large boulders, about
27 m (88 ft) SE (120  magnetic) from bench mark 5283 B 1986.  Bench mark 5283 A
1986 is not visible from bench mark 5283 B 1986.

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

                                                                                
Station ID: 9465283                         PUBLICATION DATE:  03/19/2019
Name:       NE SIDE SUMMIT ISLAND, TOGIAK BAY A               
            AK
NOAA Chart:                                 Latitude:   58° 50.8' N (  58.84670)
USGS Quad:                                  Longitude: 160° 12.6' W (-160.21001)


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


                         BENCH MARK STAMPING:  5283 B 1986
                         DESIGNATION:          946 5283 B 1986

MONUMENTATION:           Survey disk                           VM#:        15349
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   58° 50.8' N (  58.84670)          LONGITUDE: 160° 12.6' W (-160.21000)


The bench mark is a disk located in bedrock in a cove on the NE side of Summit
Island which rock lies on the north side of the northernmost point on the south
end of the cove, 0.61 m (2.0 ft) above the approximate high water line and about
0.3 m (1 ft) above the gravel at the foot of a chimney, 53.60 m (176.0 ft) SE
(145  magnetic) from bench mark 5283 C 1986.  Bench mark 5283 B 1986 is not
visible from bench mark 5283 A 1986 but is about 27 m (88 ft) NW (300  magnetic)
from bench mark 5283 A 1986.



                         BENCH MARK STAMPING:  5283 C 1986
                         DESIGNATION:          946 5283 C 1986

MONUMENTATION:           Survey disk                           VM#:        15350
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Outcrop of bedrock                    OPUS PID:        
LATITUDE:   58° 50.8' N (  58.84670)          LONGITUDE: 160° 12.6' W (-160.21000)


The bench mark is a disk lies in a cove on the NE side of Summit Island, about
30.0 m (98.4 ft) south of a creek that runs by a sauna in an outcrop of bedrock
which is about 9.0 m (29.5 ft) east of a grassy ridge, 0.15 m (0.5 ft) above the
gravel, 54 m (176 ft) NW (325  magnetic) from bench mark 5283 B 1986, 200 m (656
ft) SE (170  magnetic) from bench mark 5283 D 1986, although it is not visible.

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

                                                                                
Station ID: 9465283                         PUBLICATION DATE:  03/19/2019
Name:       NE SIDE SUMMIT ISLAND, TOGIAK BAY A               
            AK
NOAA Chart:                                 Latitude:   58° 50.8' N (  58.84670)
USGS Quad:                                  Longitude: 160° 12.6' W (-160.21001)


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


                         BENCH MARK STAMPING:  5283 E 1986
                         DESIGNATION:          946 5283 E 1986

MONUMENTATION:           Survey disk                           VM#:        15352
AGENCY:                  National Ocean Service (NOS)          IDB PID:         
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   58° 50.8' N (  58.84670)          LONGITUDE: 160° 12.6' W (-160.21000)


The bench mark is a disk which lies in bedrock on the southern face of a rocky
point on the north end of the cove, on the north end of a cove on the NE side of
Summit Island, 0.91 m (3.0 ft) above the gravel, 35.65 m (117.0 ft) north (000 
magnetic) from bench mark 5283 D 1986.

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

                                                                                
Station ID: 9465283                         PUBLICATION DATE:  03/19/2019
Name:       NE SIDE SUMMIT ISLAND, TOGIAK BAY A               
            AK
NOAA Chart:                                 Latitude:   58° 50.8' N (  58.84670)
USGS Quad:                                  Longitude: 160° 12.6' W (-160.21001)


                            T I D A L   D A T U M S 


Tidal datums at NE SIDE SUMMIT ISLAND, TOGIAK BAY A based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           June 1988 - July 1988
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9463502 PORT MOLLER, BRISTOL BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.239
     MEAN HIGH WATER                            MHW    =  2.878
     MEAN SEA LEVEL                             MSL    =  1.735
     MEAN TIDE LEVEL                            MTL    =  1.667
     MEAN LOW WATER                             MLW    =  0.455
     MEAN LOWER LOW WATER                       MLLW   =  0.000



Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     5283 D 1986                                 7.744    4.866
     5283 A 1986                                 6.705    3.827
     5283 B 1986                                 7.275    4.397
     5283 C 1986                                 6.919    4.041
     5283 E 1986                                 6.953    4.075


Foot Notes:

Data from this station was collected using methodology that does not meet CO-OPS
highest level of accuracy (no more than 10 cm, 95% Confidence Interval (CI)
referenced to a tidal datum). Recognizing that lower quality data can be used
for certain applications CO-OPS is making this data available to its users with
restraint. The average six-minute water level observations derived from this
system have an accuracy ranging from 10.0 - 30.0 cm, 95% CI on datum. Users are
cautioned to consider the accuracy of these data before using them for critical
navigational or coastal engineering purposes. 

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

                                                                                
Station ID: 9465283                         PUBLICATION DATE:  03/19/2019
Name:       NE SIDE SUMMIT ISLAND, TOGIAK BAY A               
            AK
NOAA Chart:                                 Latitude:   58° 50.8' N (  58.84670)
USGS Quad:                                  Longitude: 160° 12.6' W (-160.21001)


                             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 9465283 NE SIDE SUMMIT ISLAND, TOGIAK BAY A, AK

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services