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Bench Mark Sheet for 9452400, Skagway 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' W


To reach the tidal bench marks from the U.S. Post Office/Bank of Alaska on 6th
and Broadway, proceed SW on Broadway for five blocks, turn NW on First Avenue
and proceed for one block, turn SE on Stage Street and enter the Cypress Anville
Ore Company (private property).  Proceed down to the dock area.  The bench marks
are located in the general vicinity.  The tide gauge is located on the north
section of the intersection between pier and SE/NW running access pier adjacent
to a large ore elavator.


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


                 PRIMARY BENCH MARK STAMPING:  NO 11 1969
                         DESIGNATION:          945 2400 TIDAL 11

MONUMENTATION:           Tidal Station disk                        VM#:     1202
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID:         
SETTING CLASSIFICATION:  Bedrock


The primary bench mark is set flush with the surface of a projected segment of a
bedrock ledge, 48.80 m (160.0 ft) south of the White Pass and Yukon Railway
intersection of the spur line with the main line, 14.70 m (48.2 ft) NE of the
northern extent of a 1.20 m high (3.9 ft) chain-link fence, 2.74 m (9.0 ft) east
of the east rail of the spur line to the wharf, 1.82 m (6.0 ft) west of an
orange NOS witness post, and 0.36 m (1.2 ft) south of a 1-inch diameter anchor
bolt set in the same bedrock ledge.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' W


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


                         BENCH MARK STAMPING:  8 1959
                         DESIGNATION:          945 2400 TIDAL 8

MONUMENTATION:           Tidal Station disk                        VM#:     1207
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID:         
SETTING CLASSIFICATION:  Boulder


The benchmark is a disk set in the NE end of an 2.44 m (8.0 ft) diameter
boulder, 18.59 m (61.0 ft) east of the White Pass and Yukon Railroad Dock Road
leading to the small boat harbor, 1.52 m (5.0 ft) south of a red 9.14 m x 30.48
m (30.0 ft x 100.0 ft) corrugated metal warehouse building, 0.85 m (2.8 ft) SE
of an orange NOS witness post, and 0.91 m (3.0 ft) above ground level.



                         BENCH MARK STAMPING:  2400 E 1991
                         DESIGNATION:          945 2400 E

MONUMENTATION:           Tidal Station disk                        VM#:     3226
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Concrete foundation


The benchmark is set in the NE corner of the concrete midspan support for the
ore conveyor of the White Pass and Yukon Railway Ore Terminal, 29.57 m (97.0 ft)
SW of the first light pole on the pier, 10.30 m (33.8 ft) east of the west edge
of the concrete platform, 1.98 m (6.5 ft) south of the NE corner of the concrete
platform, and 0.42 m (1.4 ft) NE of the east corner of the building surrounding
the conveyor structure.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' W


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


                         BENCH MARK STAMPING:  2400 G 1997
                         DESIGNATION:          945 2400 G

MONUMENTATION:           Tidal Station disk                        VM#:    13746
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  bedrock


The benchmark is set in a bedrock outcrop near the traihead of the Dewey Lakes
path along White Pass and Yukon Railway tracks, 24.38 m (80.0 ft) east of the
east end of a foot bridge that crosses Pullen Creek, 22.00 m (72.2 ft) NE of a
switch-box at the junction that switches the tracks to the railway station or
the cruise ship dock, 16.15 m (53.0 ft) east of the railroad tracks, 10.67 m
(35.0 ft) ESE of the Dewey Lakes trail sign, 3.05 m (10.0 ft) NNE of the trail,
and 0.30 m (1.0 ft) above grade.



                         BENCH MARK STAMPING:  2400 J 1997
                         DESIGNATION:          945 2400 J

MONUMENTATION:           Tidal Station disk                        VM#:    13748
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  bedrock


The benchmark is a disk set in a bedrock outcrop along White Pass and Yukon
Railway tracks NE of the junction that switches the tracks to the railway
station or the cruise ship dock, 91 m (299 ft) NE of extended north face of City
of Skagway Museum, 31.50 m (103.3 ft) south of the intersection of the service
road that parallels the railroad tracks and a gravel road that leads to Spring
Street, 3.57 m (11.7 ft) east of the railroad, and 0.91 m (3 ft) above ground
level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' W


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


                         BENCH MARK STAMPING:  A 1910
                         DESIGNATION:          945 2400 A

MONUMENTATION:           Tidal Station disk                        VM#:    16722
AGENCY:                  US Coast and Geodetic Survey (USC&GS)     PID#:  TT0050
SETTING CLASSIFICATION:  Building


The bench mark is a disk set vertically in western side of an alcove on the
south side of the stone City of Skagway Museum at the east end of 7th Street, 61
m (200 ft) NW of the White Pass & Yukon Railway tracks, 5.50 m (18.0 ft) west of
a light standard along the sidewalk, 4.00 m (13.3 ft) SW of the south face of
the building, and 0.60 m (2.0 ft) NE of a SE corner mid-span of the building,
and 0.55 m (1.8 ft) above ground level.



                         BENCH MARK STAMPING:  2400 K 2002
                         DESIGNATION:          945 2400 K

MONUMENTATION:           Tidal Station disk                        VM#:    16723
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Concrete foundation


The bench mark is a disk set in the base of a 1.80 m x 0.60 m x 0.25 m (5.9 ft x
2.0 ft x 0.8 ft) concrete foundation block located on the east side of the White
Pass & Yukon Railway warehouse, 15.00 m (49.2 ft) SW of second utility pole
north of the ore conveyor, 12.71m (41.7 ft) west of a yellow and green fire
hydrant, 0.30 m (0.9 ft) east of the warehouse, and 0.25 m (0.8 ft) above ground
level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' W


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


                         BENCH MARK STAMPING:  2400 L 2012
                         DESIGNATION:          945 2400 L

MONUMENTATION:           Tidal Station disk                        VM#:    20535
AGENCY:                  National Ocean Service (NOS)              PID:         
SETTING CLASSIFICATION:  Pier


The bench mark is disk set into the top of concrete on the west end of an
east/west running walkway to the cruise ship dock south of the tide station,
47.40 m (155 ft) west of the east face of the pier, 10.40 m (34 ft) east of the
west face of the pier, 8.30 m (34 ft) south of the north face of the pier, and
0.90 m (3.0 ft) north of the south face of pier.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' W


                            T I D A L   D A T U M S 


Tidal datums at SKAGWAY, TAIYA INLET based on:

     LENGTH OF SERIES:      5 YEARS
     TIME PERIOD:           January 2007 - December 2011
     TIDAL EPOCH:           2007-2011
     CONTROL TIDE STATION:   


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

     HIGHEST OBSERVED WATER LEVEL (10/22/1945)         =  8.069
     MEAN HIGHER HIGH WATER                     MHHW   =  5.101
     MEAN HIGH WATER                            MHW    =  4.795
     MEAN SEA LEVEL                             MSL    =  2.687
     MEAN TIDE LEVEL                            MTL    =  2.645
     MEAN LOW WATER                             MLW    =  0.495
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     LOWEST  OBSERVED WATER LEVEL (12/14/2008)         = -1.964

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     NO 11 1969                                 10.937    6.142
     8 1959                                     10.660    5.865
     2400 E 1991                                 8.772    3.977
     2400 G 1997                                12.640    7.845
     2400 J 1997                                11.340    6.545
     A 1910                                     10.978    6.183
     2400 K 2002                                 9.143    4.348
     2400 L 2012                                 8.965    4.170


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' W


Foot Notes:

Certain geographic areas are experiencing rapid land movement due to uplift or
subsidence, which results in anomalous relative sea level trends compared to
most other coastal regions in the United States (see
http://tidesandcurrents.noaa.gov/sltrends/index.shtml/). In these areas, NOAA
has adopted a modified procedure for computing accepted tidal datums for the
National Water Level Observation Network (NWLON). The long-term control stations
in these areas have tidal datums updated approximately every 5 years using the
modified procedure, with the most recent update being the 2007-2011 Modified
Procedure. The adoption of this procedure was necessary to ensure that these
tidal datums accurately represent the existing stand of sea level relative to
the land. A detailed report explaining this modified procedure can be found in
the publications section of the CO-OPS Tides & Currents website at
http://tidesandcurrents.noaa.gov/pub.html.                                      
                                                                            
Bench mark 2400 L 2012 is based on one differential leveling connection and does
not meet the quality control standards of the NOS. Therefore, caution should be
used when deriving elevations for this mark.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of  8

                                                                                
Station ID: 9452400                                PUBLICATION DATE:  05/02/2014
Name:       SKAGWAY, TAIYA INLET                              
            AK
NOAA Chart: 17317                                  Latitude:         59° 27.0' N
USGS Quad:  SKAGWAY B-1                            Longitude:       135° 19.6' 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.

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Products available at 9452400 Skagway, AK

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