Superseded Bench Mark Sheet for 9458917, CHIGNIK, ANCHORAGE BAY AK

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  10/05/2000
Station ID: 9458917                                SUPERCEDED DATE:   04/21/2003
Name:       CHIGNIK, ANCHORAGE BAY                            
            ALASKA
NOAA Chart: 16566                                  Latitude:         56° 17.8' N
USGS Quad:  CHIGNIK (B-2)                          Longitude:       158° 24.0' W


To reach tidal bench marks from Alaskan Peninsula, go to the town of Chignik,
Anchorage Bay.  The bench marks abd gauge were located on the premises of the
Aleutian Dragon Fisheries cannery. 


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


                 PRIMARY BENCH MARK STAMPING:  S-1066 ATS 63 COR 4 WCMC S-2149
                                               1962 6ZE

MONUMENTATION:           Tidal Station disk                        VM#:    13156
AGENCY:                  US Coast & Geodetic Survey (USC&GS)       PID:         
SETTING CLASSIFICATION:  Steel pipe


The primary bench mark is a disk set in a steel pipe at the end of a wooden
sidewalk, 3 m (10 ft) north of the NE corner of a trailer which is the
western-most of a row of trailers located between the shore and a slough, and
0.34 m (1.1 ft) above the ground.



                         BENCH MARK STAMPING:  8917 F 1996
                         DESIGNATION:          945 8917 F

MONUMENTATION:           Tidal Station disk                        VM#:    13157
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Pavement


The bench mark is a disk set flush in the pavement outside the NE-SW running
cannery wall, and 21 m (69 ft) south of the NW corner of the ADF cannery
building.

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

                                                   PUBLICATION DATE:  10/05/2000
Station ID: 9458917                                SUPERCEDED DATE:   04/21/2003
Name:       CHIGNIK, ANCHORAGE BAY                            
            ALASKA
NOAA Chart: 16566                                  Latitude:         56° 17.8' N
USGS Quad:  CHIGNIK (B-2)                          Longitude:       158° 24.0' W


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


                         BENCH MARK STAMPING:  8917 G 1996
                         DESIGNATION:          945 8917 G

MONUMENTATION:           Tidal Station disk                        VM#:    13158
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Pavement


The bench mark is a disk set flush in the pavement, 40 m (131 ft) NW of bench
mark 8917 F 1996, 20 m (66 ft) NE of the ADF administration building, 10 m (33
ft) from the apparent high water line, and 4 m (13 ft) NE of the ADF cannery
building.



                         BENCH MARK STAMPING:  8917 H 1996
                         DESIGNATION:          945 8917 H

MONUMENTATION:           Tidal Station disk                        VM#:    13159
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Sidewalk


The bench mark is a disk set flush in the sidewalk located in front of the ADF
net house facing the water, 50 m (164 ft) NW of bench mark 8917 G 1996, and 20 m
(66 ft) from the apparent high water line.



                         BENCH MARK STAMPING:  8917 I 1996
                         DESIGNATION:          945 8917 I

MONUMENTATION:           Tidal Station disk                        VM#:    13160
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Sidewalk


The bench mark is a disk set flush at the end of a paved sidewalk and at the
start of a wooden sidewalk that runs between the shore and a row of trailers, 30
m (98 ft) NW of bench mark 8917 H 1996, 20 m (66 ft) from the apparent high
water line, and 4 m (13 ft) NE of the NE corner of a gray aluminum building.

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

                                                   PUBLICATION DATE:  10/05/2000
Station ID: 9458917                                SUPERCEDED DATE:   04/21/2003
Name:       CHIGNIK, ANCHORAGE BAY                            
            ALASKA
NOAA Chart: 16566                                  Latitude:         56° 17.8' N
USGS Quad:  CHIGNIK (B-2)                          Longitude:       158° 24.0' W


                            T I D A L   D A T U M S 


Tidal datums at CHIGNIK, ANCHORAGE BAY based on:

     LENGTH OF SERIES:      86 hws and 86 lws
     TIME PERIOD:           July 12 - August 26, 1997
     TIDAL EPOCH:           1960-1978
     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   =  2.729
     MEAN HIGH WATER                            MHW    =  2.487
     MEAN TIDE LEVEL                            MTL    =  1.455
     MEAN SEA LEVEL                             MSL    =  1.414
     MEAN LOW WATER                             MLW    =  0.424
     MEAN LOWER LOW WATER                       MLLW   =  0.000



Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     S-1066 ATS 63 COR 4 WCMC S-2149
     1962 6ZE                                    5.678    3.206
     8917 F 1996                                 6.177    3.690
     8917 G 1996                                 6.031    3.545
     8917 H 1996                                 6.331    3.844
     8917 I 1996                                 6.172    3.685


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

                                                   PUBLICATION DATE:  10/05/2000
Station ID: 9458917                                SUPERCEDED DATE:   04/21/2003
Name:       CHIGNIK, ANCHORAGE BAY                            
            ALASKA
NOAA Chart: 16566                                  Latitude:         56° 17.8' N
USGS Quad:  CHIGNIK (B-2)                          Longitude:       158° 24.0' W


                             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 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.

Return to Top
Products available at 9458917 CHIGNIK, ANCHORAGE BAY, AK