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Bench Mark Sheet for 9450987, SHAKAN STRAIT (NORTHEAST END) 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 9450987                         PUBLICATION DATE:  04/26/2011
Name:       SHAKAN STRAIT (NORTHEAST END)                     
            AK
NOAA Chart: 17387                           Latitude:   56°  8.9' N (  56.14830)
USGS Quad:  PETERSBURG A-5                  Longitude: 133° 27.6' W (-133.46000)


To reach the bench marks from the junction of El Capitan Passage and Shaken
Strait, proceed south along the eastern shore approximately 0.6 km (0.3 nm). The
bench marks are installed in the vicinity of rock outcrop. The tide gauge was
located on a wooden platform that was placed on a small wooded islet
approximately 4 m (12 ft) above the apparent high water line. 


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


                 PRIMARY BENCH MARK STAMPING:  1 1955
                         DESIGNATION:          945 0987 BM 1

MONUMENTATION:           Survey disk                           VM#:        14026
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Set into a mass of concrete in rock
                         outcrop                               OPUS PID#: BBFP35
LATITUDE:   56°  8.9' N (  56.14830)          LONGITUDE: 133° 27.6' W (-133.46000)


The Primary bench mark is a disk set in a bedrock on south side of Shaken
Strait, approximately 0.6 km (0.3 mi) south of the junction of El Capitan
Passage and Shaken Strait, 50 m (164 ft) east of a small wooded islet.

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

                                                                                
Station ID: 9450987                         PUBLICATION DATE:  04/26/2011
Name:       SHAKAN STRAIT (NORTHEAST END)                     
            AK
NOAA Chart: 17387                           Latitude:   56°  8.9' N (  56.14830)
USGS Quad:  PETERSBURG A-5                  Longitude: 133° 27.6' W (-133.46000)


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


                         BENCH MARK STAMPING:  0987 A  1998
                         DESIGNATION:          945 0987 A

MONUMENTATION:           Survey disk                           VM#:        14024
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   56°  8.9' N (  56.14830)          LONGITUDE: 133° 27.6' W (-133.46000)


The benchmark is a disk set in bedrock along the eastern shore of Shaken Strait
approximately 0.6 km (0.3 nm) south of the junction of El capitan passage and
Shaken strait, approximately 70 m (230 ft) NW (355 degrees magnetic) from bench
mark 1 1955, approximately 3 m (10 ft) below the tree line, and 3 m (10 ft)
above the apparent high water line.



                         BENCH MARK STAMPING:  0987 B 1998
                         DESIGNATION:          945 0987 B

MONUMENTATION:           Survey disk                           VM#:        14025
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   56°  8.9' N (  56.14830)          LONGITUDE: 133° 27.6' W (-133.46000)


The bench mark is a disk set in bedrock along the eastern shore of Shaken Strait
approximately 0.6 km (0.3 nm) south of the junction of El Capitan passage and
Shaken Strait, approximately 60 m (197 ft) NW (340 degrees magnetic) from bench
mark 0987 A 1998, approximately 1 m (3 ft) below the tree line, and 2 m (6 ft)
above the apparent high water line.

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

                                                                                
Station ID: 9450987                         PUBLICATION DATE:  04/26/2011
Name:       SHAKAN STRAIT (NORTHEAST END)                     
            AK
NOAA Chart: 17387                           Latitude:   56°  8.9' N (  56.14830)
USGS Quad:  PETERSBURG A-5                  Longitude: 133° 27.6' W (-133.46000)


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


                         BENCH MARK STAMPING:  2 1955
                         DESIGNATION:          945 0987 BM 2

MONUMENTATION:           Survey disk                           VM#:        14027
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   56°  8.9' N (  56.14830)          LONGITUDE: 133° 27.6' W (-133.46000)


The bench mark is a disk set on north side of  a rocky point in a bedrock on
south side of Shaken Strait, about 0.5 km (0.3 mi) SW of junction of Shaken
Strait and EL Capitan Passage, 50 m (164 ft) east of a small wooded islet.



                         BENCH MARK STAMPING:  DEAD 2 1955
                         DESIGNATION:          945 0987 BM 3
                         ALIAS:                3 1955

MONUMENTATION:           Triangulation Station disk            VM#:        14028
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   56°  8.9' N (  56.14830)          LONGITUDE: 133° 27.6' W (-133.46000)


The bench mark is a disk set in a bedrock on south side of Shaken Strait, about
0.5 km (0.3 mi) SW of junction of Shaken Strait and El Capitan Passage, 50 m
(164 ft) east of a small wooded islet.

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

                                                                                
Station ID: 9450987                         PUBLICATION DATE:  04/26/2011
Name:       SHAKAN STRAIT (NORTHEAST END)                     
            AK
NOAA Chart: 17387                           Latitude:   56°  8.9' N (  56.14830)
USGS Quad:  PETERSBURG A-5                  Longitude: 133° 27.6' W (-133.46000)


                            T I D A L   D A T U M S 


Tidal datums at SHAKAN STRAIT (NORTHEAST END) based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           May 1998 - May 1998
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9451600 SITKA, BARONOF ISLAND, SITKA SOUND


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.502
     MEAN HIGH WATER                            MHW    =  3.248
     MEAN SEA LEVEL                             MSL    =  1.837
     MEAN TIDE LEVEL                            MTL    =  1.835
     MEAN LOW WATER                             MLW    =  0.423
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1 1955                                      4.399    1.151
     0987 A  1998                                4.184    0.936
     0987 B 1998                                 4.158    0.910
     2 1955                                      4.121    0.873
     DEAD 2 1955                                 3.798    0.550


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

                                                                                
Station ID: 9450987                         PUBLICATION DATE:  04/26/2011
Name:       SHAKAN STRAIT (NORTHEAST END)                     
            AK
NOAA Chart: 17387                           Latitude:   56°  8.9' N (  56.14830)
USGS Quad:  PETERSBURG A-5                  Longitude: 133° 27.6' W (-133.46000)


                             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 9450987 SHAKAN STRAIT (NORTHEAST END), AK

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