NOAA Web Site Link Tides and Currents Home Page Transparent placeholder image

Bench Mark Sheet for 9462694, Akutan, Alaska 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 9462694                         PUBLICATION DATE:  06/19/2009
Name:       AKUTAN                                            
            AK
NOAA Chart: 16532                           Latitude:   54°  8.0' N (  54.13328)
USGS Quad:  UNIMAK A-6                      Longitude: 165° 46.6' W (-165.77731)


To reach the tide station from the float plane haul-out ramp, travel SE
approximately 100 m (330 ft) to the chain-link fence at the city dock, turn
right and proceed south approximately 20 m (66 ft) to the west face of an orange
conex shipping container which is used for storage.  The bench marks are located
in the vicinity of the dock and on the float plane haul-out ramp.


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


                 PRIMARY BENCH MARK STAMPING:  2694 A 2009
                         DESIGNATION:          946 2694 A

MONUMENTATION:           Tidal Station disk                    VM#:        19205
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID#: BBBH20
LATITUDE:   54°  8.0' N (  54.13311)          LONGITUDE: 165° 46.6' W (-165.77697)


The primary bench mark is set flush in the concrete slab foundation of the
south-eastern most bollard along the sheet-pile retaining wall abutting the city
dock, 29.25 m (96.0 ft) SE of bench mark 946 2694 B, 1.30 m (4.3 ft) NW of the
outside edge of the retaining wall, 1.26 m (4.1 ft) NE of the outside edge of
the retaining wall, and 0.45 m (1.5 ft) north of the center of the south-eastern
most bollard.

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

                                                                                
Station ID: 9462694                         PUBLICATION DATE:  06/19/2009
Name:       AKUTAN                                            
            AK
NOAA Chart: 16532                           Latitude:   54°  8.0' N (  54.13328)
USGS Quad:  UNIMAK A-6                      Longitude: 165° 46.6' W (-165.77731)


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


                         BENCH MARK STAMPING:  2694 B 2009
                         DESIGNATION:          946 2694 B

MONUMENTATION:           Tidal Station disk                    VM#:        19206
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   54°  8.0' N (  54.13328)          LONGITUDE: 165° 46.6' W (-165.77731)


The bench mark is set flush in the concrete slab foundation of the north-western
most bollard along the sheet-pile retaining wall abutting the city dock, 46.28 m
(151.8 ft) south of bench mark 946 2694 C, 29.25 m (96.0 ft) NW of bench mark
946 2694 A, 3.48 m (11.4 ft) west of a red fire hydrant, 1.50 m (4.9 ft) NE of
the center of the north-western most bollard inside of the retaining wall, and
0.68 m (2.2 ft) south of the northern edge of the retaining wall.



                         BENCH MARK STAMPING:  2694 C 2009
                         DESIGNATION:          946 2694 C

MONUMENTATION:           Tidal Station disk                    VM#:        19207
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete slab                         OPUS PID:        
LATITUDE:   54°  8.0' N (  54.13361)          LONGITUDE: 165° 46.6' W (-165.77689)


The bench mark is a set flush in concrete on the south east side of the
threshold of the overhead door leading to the Post Office warehouse, 46.28 m
(151.8 ft) north of bench mark 946 2694 B, 41.25 m (135.3 ft) east of bench mark
946 2694 D, 35.81m (117.5 ft) NNE of the center of the top of the ramp down to
the floating skiff moorage, 10.72 m (35.2 ft) ESE of the western most outside
corner of the warehouse, and 0.18 m (0.6 m) WNW of the south eastern edge of the
overhead door.

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

                                                                                
Station ID: 9462694                         PUBLICATION DATE:  06/19/2009
Name:       AKUTAN                                            
            AK
NOAA Chart: 16532                           Latitude:   54°  8.0' N (  54.13328)
USGS Quad:  UNIMAK A-6                      Longitude: 165° 46.6' W (-165.77731)


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


                         BENCH MARK STAMPING:  2694 D 2009
                         DESIGNATION:          946 2694 D

MONUMENTATION:           Tidal Station disk                    VM#:        19208
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete structure                    OPUS PID:        
LATITUDE:   54°  8.0' N (  54.13369)          LONGITUDE: 165° 46.7' W (-165.77758)


The bench mark is a disk set flush in concrete on the northern end of the large
concrete structure used as backfill for the sheet-pile wall defining the inner
side of the skiff moorage, 66.03m (216.6ft) ESE of bench mark 2694 E 2009,
41.25m (135.3ft) west of bench mark 2694 C 2009, 40.95m (134.4ft) NE of the
center of the top of the ramp down to the floating skiff moorage, 2.72m (8.9ft)
NE of the SW edge of the concrete structure, and 0.25m (0.8ft) SE of the NW edge
of the concrete structure.



                         BENCH MARK STAMPING:  2694 E 2009
                         DESIGNATION:          946 2694 E

MONUMENTATION:           Tidal Station disk                    VM#:        19209
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete pad                          OPUS PID:        
LATITUDE:   54°  8.0' N (  54.13397)          LONGITUDE: 165° 46.7' W (-165.77853)


The bench mark is set flush in the concrete pad of the float plane haul-out west
of the west edge of the ramp, 66.03 m (216.6 ft) WNW of bench mark 946 2694 D,
35.50 m (116.5 ft) ESE of the corner of the block retaining wall around the
church, 8.03 m (26.3 ft) west of the centerline of the floatplane haul-out ramp,
and 4.55 m (14.9 ft) north of the southern edge of the concrete pad.

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

                                                                                
Station ID: 9462694                         PUBLICATION DATE:  06/19/2009
Name:       AKUTAN                                            
            AK
NOAA Chart: 16532                           Latitude:   54°  8.0' N (  54.13328)
USGS Quad:  UNIMAK A-6                      Longitude: 165° 46.6' W (-165.77731)


                            T I D A L   D A T U M S 


Tidal datums at AKUTAN based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           April 2009 - April 2009
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9462620 UNALASKA, DUTCH HARBOR


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.138
     MEAN HIGH WATER                            MHW    =  1.044
     MEAN SEA LEVEL                             MSL    =  0.661
     MEAN TIDE LEVEL                            MTL    =  0.659
     MEAN LOW WATER                             MLW    =  0.274
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     2694 A 2009                                 3.355    2.311
     2694 B 2009                                 3.293    2.249
     2694 C 2009                                 3.639    2.595
     2694 D 2009                                 2.674    1.630
     2694 E 2009                                 2.042    0.998


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

                                                                                
Station ID: 9462694                         PUBLICATION DATE:  06/19/2009
Name:       AKUTAN                                            
            AK
NOAA Chart: 16532                           Latitude:   54°  8.0' N (  54.13328)
USGS Quad:  UNIMAK A-6                      Longitude: 165° 46.6' W (-165.77731)


                             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.

Return to Top
Products available at 9462694 Akutan, Alaska, AK

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