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Bench Mark Sheet for 9451287, Beecher Pass 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  7

                                                                                
Station ID: 9451287                         PUBLICATION DATE:  11/13/2003
Name:       BEECHER PASS, WRANGELL NARROWS                    
            AK
NOAA Chart: 17375                           Latitude:   56° 35.7' N (  56.59500)
USGS Quad:  PETERSBURG (C-3)                Longitude: 132° 59.2' W (-132.98700)


To reach the tidal bench marks from the Petersburg, Alaska, South Harbor public
boat launch, proceed 16.0 km (8.7 nm) south down Wrangell Narrows past Papke's
Landing state warf, continue 4.6 km (2.5 nm) south past Anchor Point,  The tide
gauge was located on the NE tip of Inlet Point on the southern shore of Beecher
Pass at its confluence with Wrangell Narrows. The tidal bench mark are located
on the beach. 


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


                 PRIMARY BENCH MARK STAMPING:  NO 4 1929
                         DESIGNATION:          945 1287 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:        17241
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Rock ledge                            OPUS PID:        
LATITUDE:   56° 35.7' N (  56.59500)          LONGITUDE: 132° 59.3' W (-132.98800)


The bench mark is a disk set in rock ledge 13.84 m (45.4 ft) SSE of bench mark
USE 54-89 1989, 14 m (45 ft) east of bench mark 945 1287 TIDAL 3, 13.17 m (43.2
ft) SW from bench mark 945 1287 TIDAL 1, and 7 m (23 ft) east of bench mark NO 5
1929.  

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

                                                                                
Station ID: 9451287                         PUBLICATION DATE:  11/13/2003
Name:       BEECHER PASS, WRANGELL NARROWS                    
            AK
NOAA Chart: 17375                           Latitude:   56° 35.7' N (  56.59500)
USGS Quad:  PETERSBURG (C-3)                Longitude: 132° 59.2' W (-132.98700)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          945 1287 TIDAL 1
                         ALIAS:                BM 1

MONUMENTATION:           Bolt                                  VM#:        17239
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Boulder                               OPUS PID:        
LATITUDE:   56° 35.7' N (  56.59500)          LONGITUDE: 132° 59.3' W (-132.98800)


The bench mark is a copper bolt set in top of rock below apparent high water
line, south of cobble beach at Inlet Point on west bank of Wrangell Narrows, 18
m (60 ft) NW from bench mark 945 1287 TIDAL 3, 13.17 m (43.2 ft) NE of bench
mark NO 4 1929, 12.13 m (39.8 ft) east of bench mark NO 5 1929, 11 m (36 ft)
east of bench mark USE 54-89 1989, and 3 m (10 ft) from an arrow cut into red
granite boulder.      

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

                                                                                
Station ID: 9451287                         PUBLICATION DATE:  11/13/2003
Name:       BEECHER PASS, WRANGELL NARROWS                    
            AK
NOAA Chart: 17375                           Latitude:   56° 35.7' N (  56.59500)
USGS Quad:  PETERSBURG (C-3)                Longitude: 132° 59.2' W (-132.98700)


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


                         BENCH MARK STAMPING:   
                         DESIGNATION:          945 1287 TIDAL 3
                         ALIAS:                BM 3

MONUMENTATION:           Drill Hole                            VM#:        17240
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Rock ledge                            OPUS PID:        
LATITUDE:   56° 35.7' N (  56.59500)          LONGITUDE: 132° 59.3' W (-132.98800)


The bench mark is a 3/4 inch drill hole with three chiseled radial lines cut in
level shelf on a prominent ledge, 22 m (73 ft) SE of bench mark USE 54-89 1989,
and 18 m (60 ft) SE from bench mark 945 1287 TIDAL 1.



                         BENCH MARK STAMPING:  NO 5 1929
                         DESIGNATION:          945 1287 TIDAL 5

MONUMENTATION:           Tidal Station disk                    VM#:        17242
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:        
SETTING CLASSIFICATION:  Rock ledge                            OPUS PID:        
LATITUDE:   56° 35.7' N (  56.59500)          LONGITUDE: 132° 59.3' W (-132.98800)


The bench mark is a disk set on a ledge, 12.13 m (39.8 ft) west of bench mark
945 1287 TIDAL 1, on the same ledge as and 7.50 m (24.6 ft) SW of bench mark USE
54-89 1989 and inside of it, 7.50 m (24.6 ft) SW of bench mark NO 4 1929, and 4
m (14ft) in front of a vertical cliff.

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

                                                                                
Station ID: 9451287                         PUBLICATION DATE:  11/13/2003
Name:       BEECHER PASS, WRANGELL NARROWS                    
            AK
NOAA Chart: 17375                           Latitude:   56° 35.7' N (  56.59500)
USGS Quad:  PETERSBURG (C-3)                Longitude: 132° 59.2' W (-132.98700)


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


                         BENCH MARK STAMPING:  1287 A 2003
                         DESIGNATION:          945 1287 A

MONUMENTATION:           Tidal Station disk                    VM#:        17243
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Granite boulder                       OPUS PID:        
LATITUDE:   56° 35.7' N (  56.59500)          LONGITUDE: 132° 59.3' W (-132.98800)


The bench mark is a disk set in top of 1 m x 1m x 0.27 m (4 ft x 4 ft x 0.9 ft)
high granite boulder firmly rooted at apparent high water line immediately SE of
Inlet Point, and 11m (35 ft) north of bench mark 1287 B 2003.



                         BENCH MARK STAMPING:  1287 B 2003
                         DESIGNATION:          945 1287 B

MONUMENTATION:           Tidal Station disk                    VM#:        17244
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Granite boulder                       OPUS PID:        
LATITUDE:   56° 35.7' N (  56.59500)          LONGITUDE: 132° 59.3' W (-132.98800)


The bench mark is a disk set in the center of bottom of two overlapping flat
granite slabs located near the southern extents of Inlet Point, 17 m (56 ft)
north of cobble beach, 11 m (35 ft) south of bench mark 1287 A 2003, and 3.44 m
(11.3 ft) west of a 10 inch "x" chiseled into black granite boulder at grass
line.

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

                                                                                
Station ID: 9451287                         PUBLICATION DATE:  11/13/2003
Name:       BEECHER PASS, WRANGELL NARROWS                    
            AK
NOAA Chart: 17375                           Latitude:   56° 35.7' N (  56.59500)
USGS Quad:  PETERSBURG (C-3)                Longitude: 132° 59.2' W (-132.98700)


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


                         BENCH MARK STAMPING:  USE 54-89 1989
                         DESIGNATION:          945 1287 USE 54-89

MONUMENTATION:           Tidal Station disk                    VM#:        17245
AGENCY:                  US Army Corps of Engineers (USCOE)    IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   56° 35.7' N (  56.59500)          LONGITUDE: 132° 59.3' W (-132.98800)


The bench mark is a disk set in bedrock, 22 m (73 ft) NW of bench mark 945 1287
TIDAL 3, 13.84 m (45.4 ft) NNW of bench mark NO 4 1929, 11 m (36 ft) west of
bench mark 945 1287 TIDAL 1, and 7.50 m (24.6 ft) NE of bench mark NO 5 1929.   


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

                                                                                
Station ID: 9451287                         PUBLICATION DATE:  11/13/2003
Name:       BEECHER PASS, WRANGELL NARROWS                    
            AK
NOAA Chart: 17375                           Latitude:   56° 35.7' N (  56.59500)
USGS Quad:  PETERSBURG (C-3)                Longitude: 132° 59.2' W (-132.98700)


                            T I D A L   D A T U M S 


Tidal datums at BEECHER PASS, WRANGELL NARROWS based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           August 2003 - September 2003
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9450460 KETCHIKAN, TONGASS NARROWS


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

     MEAN HIGHER HIGH WATER                     MHHW   =  4.716
     MEAN HIGH WATER                            MHW    =  4.445
     MEAN TIDE LEVEL                            MTL    =  2.457
     MEAN SEA LEVEL                             MSL    =  2.409
     MEAN LOW WATER                             MLW    =  0.468
     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 4 1929                                   6.340    1.895
     945 1287 TIDAL 1                            3.750   -0.695
     945 1287 TIDAL 3                            6.139    1.693
     NO 5 1929                                   5.519    1.074
     1287 A 2003                                 5.027    0.582
     1287 B 2003                                 4.666    0.221
     USE 54-89 1989                              4.929    0.484


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

                                                                                
Station ID: 9451287                         PUBLICATION DATE:  11/13/2003
Name:       BEECHER PASS, WRANGELL NARROWS                    
            AK
NOAA Chart: 17375                           Latitude:   56° 35.7' N (  56.59500)
USGS Quad:  PETERSBURG (C-3)                Longitude: 132° 59.2' W (-132.98700)


                             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 9451287 Beecher Pass, AK

Revised: 08/08/2018
NOAA / National Ocean Service
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