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Bench Mark Sheet for 9459163, Herendeen Island, Shumagin Islands 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 9459163                         PUBLICATION DATE:  10/30/2009
Name:       HERENDEEN ISLAND, SHUMAGIN ISLANDS                
            AK
NOAA Chart: 16556                           Latitude:   55°  3.9' N (  55.06556)
USGS Quad:  STEPOVAK BAY (1963)             Longitude: 159° 25.1' W (-159.41867)


Herendeen Island is located directly north of Little Koniuji Island; the two are
separated by Northwest Harbor. All five(5) newly installed bench marks and the
newly stalled HORCON benchmark are in close proximity to the shoreline and lie
below a grass-covered ledge which parallels the shoreline. The tidal benchmarks
span a linear region of approximately 250 meters (820 feet), beginning with 
9459163A 2009  in the north and ending with  9459163E 2009  at the southernmost
extent.  The Herendeen Island tide gauge (#945-9163) is located on the southwest
facing shore of Herendeen Island. 


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


                 PRIMARY BENCH MARK STAMPING:  9163 A 2009
                         DESIGNATION:          945 9163 A

MONUMENTATION:           Tidal Station disk                    VM#:        19286
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Granite bedrock                       OPUS PID:        
LATITUDE:   55°  4.1' N (  55.06786)          LONGITUDE: 159° 25.3' W (-159.42217)


The primary bench mark is a disk set fluch into granite bedrock at the base of a
rock ledge, located at the NW extent of a grassy recess in the bedrock and 7 m
(23 ft) inshore at apparent high water.

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

                                                                                
Station ID: 9459163                         PUBLICATION DATE:  10/30/2009
Name:       HERENDEEN ISLAND, SHUMAGIN ISLANDS                
            AK
NOAA Chart: 16556                           Latitude:   55°  3.9' N (  55.06556)
USGS Quad:  STEPOVAK BAY (1963)             Longitude: 159° 25.1' W (-159.41867)


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


                         BENCH MARK STAMPING:  9163 B 2009
                         DESIGNATION:          945 9163 B

MONUMENTATION:           Tidal Station disk                    VM#:        19287
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Granite boulder                       OPUS PID:        
LATITUDE:   55°  4.1' N (  55.06756)          LONGITUDE: 159° 25.3' W (-159.42189)


The bench mark is a disk set into a large, broad, granite boulder, located
beneath the rock ledge paralleling the shoreline and 3 m (10 ft) inshore of the
apparent high water line.



                         BENCH MARK STAMPING:  9163 C 2009
                         DESIGNATION:          945 9163 C

MONUMENTATION:           Tidal Station disk                    VM#:        19288
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Boulder                               OPUS PID:        
LATITUDE:   55°  4.0' N (  55.06728)          LONGITUDE: 159° 25.3' W (-159.42156)


The bench mark is a disk set into the outer tip of a large, flat boulder,
located 30 m (98 ft) east of bench mark 945 9163 B, and 1.0 m (3.2 ft) inshore
of the apparent high water line.

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

                                                                                
Station ID: 9459163                         PUBLICATION DATE:  10/30/2009
Name:       HERENDEEN ISLAND, SHUMAGIN ISLANDS                
            AK
NOAA Chart: 16556                           Latitude:   55°  3.9' N (  55.06556)
USGS Quad:  STEPOVAK BAY (1963)             Longitude: 159° 25.1' W (-159.41867)


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


                         BENCH MARK STAMPING:  9163 D 2009
                         DESIGNATION:          945 9163 D

MONUMENTATION:           Tidal Station disk                    VM#:        19289
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID:        
LATITUDE:   55°  4.0' N (  55.06697)          LONGITUDE: 159° 25.3' W (-159.42092)


The bench mark is a disk set into the flat top of a large fractured bedrock
outcorp, located 70 m (230 ft) from the HORCON monument and 50 m (164 ft) from
bench mark 945 9163 C.



                         BENCH MARK STAMPING:  9163 E 2009
                         DESIGNATION:          945 9163 E

MONUMENTATION:           Tidal Station disk                    VM#:        19290
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Boulder                               OPUS PID:        
LATITUDE:   55°  4.0' N (  55.06647)          LONGITUDE: 159° 25.2' W (-159.42033)


The bench mark is a disk set into the flat top of a boulder below the grassy
ledge, located 70 m (230 ft) from bench mark 945 9163 D and less than 10 m (33
ft) from HORCON monument.           

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

                                                                                
Station ID: 9459163                         PUBLICATION DATE:  10/30/2009
Name:       HERENDEEN ISLAND, SHUMAGIN ISLANDS                
            AK
NOAA Chart: 16556                           Latitude:   55°  3.9' N (  55.06556)
USGS Quad:  STEPOVAK BAY (1963)             Longitude: 159° 25.1' W (-159.41867)


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


                         BENCH MARK STAMPING:  HORCON
                         DESIGNATION:          HERENDEEN 2009

MONUMENTATION:           Horizontal Station disk               VM#:        19291
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Bedrock                               OPUS PID#: BBBK57
LATITUDE:   55°  4.0' N (  55.06647)          LONGITUDE: 159° 25.2' W (-159.42025)


The bench mark is a disk set flush into a broad, fractured, exposed section of
bedrock at the base of a vegetation-covered slope and circled by a ring of
grass, located less than 10 m (33 ft) from bench mark 945 9163 E.

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

                                                                                
Station ID: 9459163                         PUBLICATION DATE:  10/30/2009
Name:       HERENDEEN ISLAND, SHUMAGIN ISLANDS                
            AK
NOAA Chart: 16556                           Latitude:   55°  3.9' N (  55.06556)
USGS Quad:  STEPOVAK BAY (1963)             Longitude: 159° 25.1' W (-159.41867)


                            T I D A L   D A T U M S 


Tidal datums at HERENDEEN ISLAND, SHUMAGIN ISLANDS based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           July 2009 - July 2009
     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   =  2.252
     MEAN HIGH WATER                            MHW    =  2.020
     MEAN TIDE LEVEL                            MTL    =  1.216
     MEAN SEA LEVEL                             MSL    =  1.199
     MEAN LOW WATER                             MLW    =  0.413
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     9163 A 2009                                 3.243    1.223
     9163 B 2009                                 3.359    1.339
     9163 C 2009                                 3.389    1.369
     9163 D 2009                                 4.564    2.544
     9163 E 2009                                 5.227    3.207
     HORCON                                      4.978    2.958


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

                                                                                
Station ID: 9459163                         PUBLICATION DATE:  10/30/2009
Name:       HERENDEEN ISLAND, SHUMAGIN ISLANDS                
            AK
NOAA Chart: 16556                           Latitude:   55°  3.9' N (  55.06556)
USGS Quad:  STEPOVAK BAY (1963)             Longitude: 159° 25.1' W (-159.41867)


                             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 9459163 Herendeen Island, Shumagin Islands, AK

Revised: 10/15/2013
NOAA / National Ocean Service
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