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Bench Mark Sheet for 9454691, HERRING POINT, KNIGHT ISLAND, PR WIL SND 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  4

                                                                                
Station ID: 9454691                         PUBLICATION DATE:  04/06/2011
Name:       HERRING POINT, KNIGHT ISLAND, PR WIL SND          
            AK
NOAA Chart: 16700                           Latitude:   60° 28.5' N (  60.47500)
USGS Quad:  Seward B-2                      Longitude: 147° 47.5' W (-147.79200)


To reach the bench marks, they are located on a rocky point on the NW side of
and at the mouth of a small bay that is approximately 1.4 km (0.9 mi) south of
the north tip of Herring Point on Knight Island.  The station was reached by
boat.


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


                 PRIMARY BENCH MARK STAMPING:  4691 B 1978

MONUMENTATION:           Tidal Station disk                    VM#:        13296
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Cemented in a drill hole              OPUS PID:        
LATITUDE:   60° 28.5' N (  60.47500)          LONGITUDE: 147° 47.5' W (-147.79200)


The primary bench mark is a disk cemented in a drill hole on a north-south
running rocky spine, 7.62 m (25.0 ft) south of the tree line, 20.79 m (68.2 ft)
east by SE of bench mark 4591 C 1978, and approximately 1.83 m (6.0 ft) above
the apparent high water line.



                         BENCH MARK STAMPING:  4691 C 1978

MONUMENTATION:           Tidal Station disk                    VM#:        13834
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Cemented in a drill hole              OPUS PID:        
LATITUDE:   60° 28.5' N (  60.47500)          LONGITUDE: 147° 47.5' W (-147.79200)


The bench mark is a disk cemented in a drill hole near the south side of a large
rock point, approximately 7.62 m (25.0 ft) north of the south edge, 6 m (20 ft)
east of the west edge, 14.17 m (46.5 ft) SE of bench mark 4691 D 1978, and 2.74
m (9.0 ft) above the apparent high water line.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                                                
Station ID: 9454691                         PUBLICATION DATE:  04/06/2011
Name:       HERRING POINT, KNIGHT ISLAND, PR WIL SND          
            AK
NOAA Chart: 16700                           Latitude:   60° 28.5' N (  60.47500)
USGS Quad:  Seward B-2                      Longitude: 147° 47.5' W (-147.79200)


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


                         BENCH MARK STAMPING:  4691 D 1978

MONUMENTATION:           Tidal Station disk                    VM#:        13835
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Cemented in a drill hole              OPUS PID:        
LATITUDE:   60° 28.5' N (  60.47500)          LONGITUDE: 147° 47.5' W (-147.79200)


The bench mark is a disk cemented in a drill hole near the south side of a large
rock point, approximately 3 m (10 ft) east of the west edge, 6 m (20 ft) north
of the south edge, 14.17 m (46.5 ft) NW of bench mark 4691 C 1978, and
approximately 2.74 m (9.0 ft) above the apparent high water line.



                         BENCH MARK STAMPING:  4691 E 1978

MONUMENTATION:           Tidal Station disk                    VM#:        13836
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Cemented in a drill hole              OPUS PID:        
LATITUDE:   60° 28.5' N (  60.47500)          LONGITUDE: 147° 47.5' W (-147.79200)


The bench mark is a disk cemented in a drill hole on the top of an oblivious
rocky knoll on the NE side of a large rock point, 22.04 m (72.3 ft) north by NW
of bench mark 4691 D 1978, and approximately 5 m (16 ft) above the apparent high
water line.



                         BENCH MARK STAMPING:  4691 F 1996

MONUMENTATION:           Tidal Station disk                    VM#:        13837
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Set in bedrock                        OPUS PID:        
LATITUDE:   60° 28.5' N (  60.47500)          LONGITUDE: 147° 47.5' W (-147.79200)


The bench mark is a disk set in bedrock on the south end of a small rocky point,
2 m (7 ft) north of the south tip of the point, approximately 10 m (33 ft) SE of
bench mark 4691 B 1978, and approximately 1 m (3 ft) above the apparent high
water line.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                                                
Station ID: 9454691                         PUBLICATION DATE:  04/06/2011
Name:       HERRING POINT, KNIGHT ISLAND, PR WIL SND          
            AK
NOAA Chart: 16700                           Latitude:   60° 28.5' N (  60.47500)
USGS Quad:  Seward B-2                      Longitude: 147° 47.5' W (-147.79200)


                            T I D A L   D A T U M S 


Tidal datums at HERRING POINT, KNIGHT ISLAND, PR WIL SND based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           October 1996 & August 1998 - September 1998
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9454240 VALDEZ, PRINCE WILLIAM SOUND


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.634
     MEAN HIGH WATER                            MHW    =  3.357
     MEAN SEA LEVEL                             MSL    =  1.944
     MEAN TIDE LEVEL                            MTL    =  1.905
     MEAN LOW WATER                             MLW    =  0.453
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     4691 B 1978                                 4.932    1.575
     4691 C 1978                                 5.799    2.442
     4691 D 1978                                 5.839    2.482
     4691 E 1978                                 8.046    4.689
     4691 F 1996                                 3.758    0.401


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

                                                                                
Station ID: 9454691                         PUBLICATION DATE:  04/06/2011
Name:       HERRING POINT, KNIGHT ISLAND, PR WIL SND          
            AK
NOAA Chart: 16700                           Latitude:   60° 28.5' N (  60.47500)
USGS Quad:  Seward B-2                      Longitude: 147° 47.5' W (-147.79200)


                             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 9454691 HERRING POINT, KNIGHT ISLAND, PR WIL SND, AK

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