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Bench Mark Sheet for 9456717, NUKSHAK ISLAND, SHELIKOF STRAIT 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  6

                                                                                
Station ID: 9456717                         PUBLICATION DATE:  04/21/2003
Name:       NUKSHAK ISLAND, SHELIKOF STRAIT                   
            AK
NOAA Chart: 16603                           Latitude:   58° 23.5' N (  58.39170)
USGS Quad:  Mount Katmai (B-1)              Longitude: 153° 57.5' W (-153.95800)


To reach the tidal bench marks from Larsen Bay, navigate 59 km (32 nm) NW
through Uyak Bay, then 110 km (60 nm) through Shelikof Strait, then proceed to
Nukshak Island which is located due east of Cape Nukshak on the west side of
Shelikof Strait, NE of Kukak Bay.  The bench marks are located on a boulder
beach on the north side of the island around the head of a cove in the middle of
the island.  The gage sensor and staff were located in a rock crevice on the
east side of the cove.


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


                 PRIMARY BENCH MARK STAMPING:  NO 3 1971
                         DESIGNATION:          945 6717 TIDAL 3

MONUMENTATION:           Tidal Station disk                    VM#:         9638
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Boulder                               OPUS PID:        
LATITUDE:   58° 23.5' N (  58.39170)          LONGITUDE: 153° 57.4' W (-153.95700)


The bench mark is a disk set on the east side of the boulder beach in the top of
a jagged 2 m (5 ft) high rock outcrop which is at the base of the bluff, and 5 m
(15 ft) south of the shore line.

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

                                                                                
Station ID: 9456717                         PUBLICATION DATE:  04/21/2003
Name:       NUKSHAK ISLAND, SHELIKOF STRAIT                   
            AK
NOAA Chart: 16603                           Latitude:   58° 23.5' N (  58.39170)
USGS Quad:  Mount Katmai (B-1)              Longitude: 153° 57.5' W (-153.95800)


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


                         BENCH MARK STAMPING:  NO 4 1971
                         DESIGNATION:          945 6717 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:         9639
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   58° 23.5' N (  58.39170)          LONGITUDE: 153° 57.4' W (-153.95700)


The bench mark is a disk set on the west side of the boulder beach at the base
of a 9 m (30 ft) high rock bluff in a rock outcrop, 15 m (50 ft) NW of the
vegetation line across the gap at the head of the cove, and 1 m (4 ft) above the
cobbles on the beach.



                         BENCH MARK STAMPING:  NO 5 1971
                         DESIGNATION:          945 6717 TIDAL 5

MONUMENTATION:           Tidal Station disk                    VM#:         9640
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   58° 23.5' N (  58.39170)          LONGITUDE: 153° 57.4' W (-153.95700)


The bench mark is a disk set just east of the center of the boulder beach in the
highest and most northern rock outcrop, 34 m (110 ft) east of the gap at the
head of the cove, 21 m (70 ft) SW of bench mark No 3 1971, 3 m (10 ft) north of
a 12 m (40 ft) high rock bluff, and 0.46 m (1.5 ft) above the surrounding
boulders.

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

                                                                                
Station ID: 9456717                         PUBLICATION DATE:  04/21/2003
Name:       NUKSHAK ISLAND, SHELIKOF STRAIT                   
            AK
NOAA Chart: 16603                           Latitude:   58° 23.5' N (  58.39170)
USGS Quad:  Mount Katmai (B-1)              Longitude: 153° 57.5' W (-153.95800)


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


                         BENCH MARK STAMPING:  NO 2 RESET
                         DESIGNATION:          945 6717 TIDAL 2 RESET

MONUMENTATION:           Tidal Station disk                    VM#:         9641
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   58° 23.5' N (  58.39170)          LONGITUDE: 153° 57.4' W (-153.95700)


The bench mark is a disk set near the center of the boulder beach in the east
end of a 3 m (10 ft) diamond-shaped rock, just above the shore line.



                         BENCH MARK STAMPING:  6717 A 2000
                         DESIGNATION:          945 6717 A

MONUMENTATION:           Tidal Station disk                    VM#:        16240
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   58° 23.5' N (  58.39170)          LONGITUDE: 153° 57.4' W (-153.95700)


The bench mark is a disk set in bedrock at the bottom of a rocky outcrop, 3m (10
ft) seaward of a flat bedrock cliff that is approximately 30 m (100 ft) high,
and 0.61 m (2.0 ft) above ground level.

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

                                                                                
Station ID: 9456717                         PUBLICATION DATE:  04/21/2003
Name:       NUKSHAK ISLAND, SHELIKOF STRAIT                   
            AK
NOAA Chart: 16603                           Latitude:   58° 23.5' N (  58.39170)
USGS Quad:  Mount Katmai (B-1)              Longitude: 153° 57.5' W (-153.95800)


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


                         BENCH MARK STAMPING:  6717 B 2000
                         DESIGNATION:          945 6717 B

MONUMENTATION:           Tidal Station disk                    VM#:        16241
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   58° 23.5' N (  58.39170)          LONGITUDE: 153° 57.4' W (-153.95700)


The bench mark is a disk set flush in bedrock, west of a boulder beach and grass
knoll, 34.70 m (113.8 ft) east of bench mark NO 2 RESET, and 1 m (3 ft) above
the base of a cliff.

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

                                                                                
Station ID: 9456717                         PUBLICATION DATE:  04/21/2003
Name:       NUKSHAK ISLAND, SHELIKOF STRAIT                   
            AK
NOAA Chart: 16603                           Latitude:   58° 23.5' N (  58.39170)
USGS Quad:  Mount Katmai (B-1)              Longitude: 153° 57.5' W (-153.95800)


                            T I D A L   D A T U M S 


Tidal datums at NUKSHAK ISLAND, SHELIKOF STRAIT based on:

     LENGTH OF SERIES:      1 Month
     TIME PERIOD:           June 2000 - June 2000
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9459450 SAND POINT, POPOF ISLAND


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

     MEAN HIGHER HIGH WATER                     MHHW   =  4.210
     MEAN HIGH WATER                            MHW    =  3.970
     MEAN TIDE LEVEL                            MTL    =  2.230
     MEAN SEA LEVEL                             MSL    =  2.216
     MEAN LOW WATER                             MLW    =  0.491
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 3 1971                                   5.173    1.203
     NO 4 1971                                   6.274    2.304
     NO 5 1971                                   5.553    1.583
     NO 2 RESET                                  4.724    0.754
     6717 A 2000                                 5.248    1.278
     6717 B 2000                                 7.970    4.000


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

                                                                                
Station ID: 9456717                         PUBLICATION DATE:  04/21/2003
Name:       NUKSHAK ISLAND, SHELIKOF STRAIT                   
            AK
NOAA Chart: 16603                           Latitude:   58° 23.5' N (  58.39170)
USGS Quad:  Mount Katmai (B-1)              Longitude: 153° 57.5' W (-153.95800)


                             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 9456717 NUKSHAK ISLAND, SHELIKOF STRAIT, AK

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