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Bench Mark Sheet for 9458907, Castle Bay 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 9458907                         PUBLICATION DATE:  04/21/2003
Name:       CASTLE BAY                                        
            AK
NOAA Chart: 16566                           Latitude:   56° 13.9' N (  56.23170)
USGS Quad:  CHIGNIK (A-1)                   Longitude: 158° 20.6' W (-158.34300)


To reach the tidal bench marks from Chignik via boat, proceed NNE out of
Anchorage Bay 6.0 km (3.2 nm), then ESE 15 km (8 nm) to Jack Point, then WSW 15
km (8 nm) along the north shore of Castle Bay to the head of the NW Arm and a
small curve of flat land which projects south from the mainland.  Four of the
bench marks are located east of the point along a rock cliff shore.  The
remaining bench marks are on the flat land, inland from the shore.  The tide
station was located at the top of the stone beach, just east of where the beach
curves to the south.


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


                 PRIMARY BENCH MARK STAMPING:  8907 B 2001
                         DESIGNATION:          945 8907 B

MONUMENTATION:           Tidal Station disk                    VM#:        16595
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 13.9' N (  56.23170)          LONGITUDE: 158° 20.6' W (-158.34300)


The primary bench mark is a disk set in a drill hole in a rock outcrop at the
west end of the rock cliff shore, 203.28 m (666.9 ft) east of bench mark 8907 A
2001, 25.12 m (82.4 ft) WSW of bench mark 8907 C 2001, 1.50 m (4.9 ft) below the
vegetation line, 0.50 m (1.6 ft) south of the vertical rock face, and 0.20 m
(0.7 ft) above the stone beach.

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

                                                                                
Station ID: 9458907                         PUBLICATION DATE:  04/21/2003
Name:       CASTLE BAY                                        
            AK
NOAA Chart: 16566                           Latitude:   56° 13.9' N (  56.23170)
USGS Quad:  CHIGNIK (A-1)                   Longitude: 158° 20.6' W (-158.34300)


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


                         BENCH MARK STAMPING:  8907 A 2001
                         DESIGNATION:          945 8907 A

MONUMENTATION:           Flange-encased Rod                    VM#:        16594
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   56° 13.9' N (  56.23170)          LONGITUDE: 158° 20.6' W (-158.34300)


The bench mark is a stainless steel rod located on a small rise inland from
where the shoreline curves out to the south, 214.60 m (704.1 ft) ENE of bench
mark New 1924, 203.28 m (666.9 ft) west of bench mark 8907 B 2001, 68 m (223 ft)
north of the stone beach, and 11 m (36 ft) north of a low sand depression.  The
datum point is set 0.03 m (0.1 ft) below ground, being the top of a stainless
steel rod with a rounded top and punchmark in the center, driven 6.7 m (22 ft)
to refusal, and encased in a 5-inch PVC pipe with aluminum NOS logo cap.



                         BENCH MARK STAMPING:  8907 C 2001
                         DESIGNATION:          945 8907 C

MONUMENTATION:           Tidal Station disk                    VM#:        16596
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 13.9' N (  56.23170)          LONGITUDE: 158° 20.6' W (-158.34300)


The bench mark is a disk set in a drill hole in a rock outcrop along a rock
cliff shore, 38.32 m (125.7 ft) WSW of bench mark 8907 D 2001, 25.12 m (82.4 ft)
east of bench mark 8907 B 2001, 3.5 m (11.5 ft) below the vegetation line, 2.0 m
(6.6 ft) east of a narrow recess in the rock wall,  and 1.0 m (3.3 ft) above the
rock beach.

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

                                                                                
Station ID: 9458907                         PUBLICATION DATE:  04/21/2003
Name:       CASTLE BAY                                        
            AK
NOAA Chart: 16566                           Latitude:   56° 13.9' N (  56.23170)
USGS Quad:  CHIGNIK (A-1)                   Longitude: 158° 20.6' W (-158.34300)


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


                         BENCH MARK STAMPING:  8907 D 2001
                         DESIGNATION:          945 8907 D

MONUMENTATION:           Tidal Station disk                    VM#:        16597
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 13.9' N (  56.23170)          LONGITUDE: 158° 20.6' W (-158.34300)


The bench mark is a disk set in a drill hole in a flat, gray rock outcrop along
a rock cliff shore, 51.64 m (169.4 ft) WSW of bench mark 8907 E 2001, 38.32 m
(125.7 ft) ENE of bench mark 8907 C 2001, 13.0 m (42.7 ft) west of an
intermittent waterfall, 2.70 m (8.9 ft) south of the cliff face, and 4 m (13 ft)
below the top of the cliff.



                         BENCH MARK STAMPING:  8907 E 2001
                         DESIGNATION:          945 8907 E

MONUMENTATION:           Tidal Station disk                    VM#:        16598
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   56° 13.9' N (  56.23170)          LONGITUDE: 158° 20.6' W (-158.34300)


The bench mark is a disk set in a drill hole in a flat, black rock outcrop along
a rock cliff shore, 51.64 m (169.4 ft) ENE of bench mark 8907 D 2001, 3.0 m (9.8
ft) south of the cliff face, and level with the boulder beach.

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

                                                                                
Station ID: 9458907                         PUBLICATION DATE:  04/21/2003
Name:       CASTLE BAY                                        
            AK
NOAA Chart: 16566                           Latitude:   56° 13.9' N (  56.23170)
USGS Quad:  CHIGNIK (A-1)                   Longitude: 158° 20.6' W (-158.34300)


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


                         BENCH MARK STAMPING:  NEW 1924
                         DESIGNATION:          945 8907 NEW

MONUMENTATION:           Triangulation Station disk            VM#:        16608
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Boulder                               OPUS PID:        
LATITUDE:   56° 13.9' N (  56.23170)          LONGITUDE: 158° 20.6' W (-158.34300)


The bench mark is a disk set in a 0.40 m x 0.50 m (1.3 ft x 1.6 ft) boulder,
214.60 m (704.1 ft) WSW of bench mark 8907 A 2001, 22.33 m (73.3 ft) ESE of
bench mark NEW RM 1 1924, 9.24 m (30.3 ft) north of the edge of vegetation along
the stone beach, and flush with the ground.



                         BENCH MARK STAMPING:  RM 1 1924
                         DESIGNATION:          945 8907 RM 1

MONUMENTATION:           Reference Mark disk                   VM#:        16610
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Boulder                               OPUS PID:        
LATITUDE:   56° 13.8' N (  56.23000)          LONGITUDE: 158° 20.6' W (-158.34300)


The bench mark is a disk set in a 1 m x 0.25 m (2 ft x 0.8 ft) oblong boulder,
22.33 m (73.3 ft) WNW of bench mark NEW 1924, 9.9 m (32.5 ft) north of the edge
of vegetation along the stone beach, and flush with the ground.

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

                                                                                
Station ID: 9458907                         PUBLICATION DATE:  04/21/2003
Name:       CASTLE BAY                                        
            AK
NOAA Chart: 16566                           Latitude:   56° 13.9' N (  56.23170)
USGS Quad:  CHIGNIK (A-1)                   Longitude: 158° 20.6' W (-158.34300)


                            T I D A L   D A T U M S 


Tidal datums at CASTLE BAY based on:

     LENGTH OF SERIES:      1 Month
     TIME PERIOD:           July 2001 - July 2001
     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   =  2.689
     MEAN HIGH WATER                            MHW    =  2.441
     MEAN TIDE LEVEL                            MTL    =  1.439
     MEAN SEA LEVEL                             MSL    =  1.417
     MEAN LOW WATER                             MLW    =  0.437
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     8907 B 2001                                 4.353    1.912
     8907 A 2001                                 7.875    5.434
     8907 C 2001                                 4.077    1.636
     8907 D 2001                                 2.920    0.479
     8907 E 2001                                 2.116   -0.325
     NEW 1924                                    5.884    3.443
     RM 1 1924                                   5.907    3.466


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

                                                                                
Station ID: 9458907                         PUBLICATION DATE:  04/21/2003
Name:       CASTLE BAY                                        
            AK
NOAA Chart: 16566                           Latitude:   56° 13.9' N (  56.23170)
USGS Quad:  CHIGNIK (A-1)                   Longitude: 158° 20.6' W (-158.34300)


                             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 9458907 Castle Bay, AK

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