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Bench Mark Sheet for 9455204, UPPER NORTHWESTERN FIORD 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 9455204                         PUBLICATION DATE:  04/21/2003
Name:       UPPER NORTHWESTERN FIORD                          
            AK
NOAA Chart: 16682                           Latitude:   59° 47.4' N (  59.79000)
USGS Quad:  SELDOVIA (D-1)                  Longitude: 150°  1.9' W (-150.03200)


To reach the benchmarks from Seward via boat, proceed 15 km (8 nm) SSE along
Resurrection Bay to Calisto Head, then 32.5 km (17.6 nm) south along
Resurrection Bay to Aialik Cape, then 9.1 km (4.9 nm) west across Aialik Bay to
the axis of Aialik Bay north of Harbor Island, then 10.4 km (5.6 nm) SSW to the
center of the passage between Aligo Point and the southern tip of Granite
Island, then 25.0 km (13.5 nm) NW along Granite Passage and Harris Bay to the
tide station on a small island at high water near the SE corner of Striation
Island. The benchmarks are located along the east-west axis of the island. The
tide station was located between benchmarks 9455204 B 2000 and 9455204 C 2000.


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


                 PRIMARY BENCH MARK STAMPING:  9455204 A 2000
                         DESIGNATION:          945 5204 A

MONUMENTATION:           Tidal Station disk                    VM#:        16356
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 47.4' N (  59.79000)          LONGITUDE: 150°  1.9' W (-150.03200)


The primary benchmark is a disk set in a rock outcrop on the SE side of the
island, 13 m (43 ft) NE of benchmark 9455204 B 2000, 5 m (16 ft) NW of a
stainless steel eyebolt cemented into rock, 4 m (14 ft) north of a stainless
steel eye bolt cemented into rock, and 4 m (12 ft) above the apparent high water
line.

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

                                                                                
Station ID: 9455204                         PUBLICATION DATE:  04/21/2003
Name:       UPPER NORTHWESTERN FIORD                          
            AK
NOAA Chart: 16682                           Latitude:   59° 47.4' N (  59.79000)
USGS Quad:  SELDOVIA (D-1)                  Longitude: 150°  1.9' W (-150.03200)


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


                         BENCH MARK STAMPING:  9455204 B 2000
                         DESIGNATION:          945 5204 B

MONUMENTATION:           Tidal Station disk                    VM#:        16357
AGENCY:                  Natonal Ocean Service (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 47.4' N (  59.79000)          LONGITUDE: 150°  1.9' W (-150.03200)


The benchmark is a disk set in a rock outcrop on top of the south side of the
island, 49 m (161 ft) ESE of benchmark 9455204 E 2000, 31.61 m (103.7 ft) east
of benchmark 9455204 D 2000, 18 m (59 ft) east of benchmark 9455204 C 2000, and
12 m (39 ft) WSW of a steel eyebolt cemented into rock.



                         BENCH MARK STAMPING:  9455204 C 2000
                         DESIGNATION:          945 5204 C

MONUMENTATION:           Tidal Station disk                    VM#:        16358
AGENCY:                  Natonal Ocean Service (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 47.4' N (  59.79000)          LONGITUDE: 150°  1.9' W (-150.03200)


The benchmark is a disk set in a rock outcrop on the top ridge of the island 37
m x 4m (121 ft x 13 ft) wide, 32 m (105 ft)  east of benchmark 9455204 E 2000,
18 m (59 ft) west of benchmark 9455204 B 2000, 14 m  (47 ft) east of benchmark
9455204 D 2000, 12 m (39 ft) WSW of the highest point of the ridge, 6 m (20 ft)
from the south tip of the ridge, and 1 m (3 ft) from the north edge of the
ridge.

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

                                                                                
Station ID: 9455204                         PUBLICATION DATE:  04/21/2003
Name:       UPPER NORTHWESTERN FIORD                          
            AK
NOAA Chart: 16682                           Latitude:   59° 47.4' N (  59.79000)
USGS Quad:  SELDOVIA (D-1)                  Longitude: 150°  1.9' W (-150.03200)


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


                         BENCH MARK STAMPING:  9455204 D 2000
                         DESIGNATION:          945 5204 D

MONUMENTATION:           Tidal Station disk                    VM#:        16359
AGENCY:                  Natonal Ocean Service (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 47.4' N (  59.79000)          LONGITUDE: 150°  1.9' W (-150.03200)


The benchmark is a disk set in a rock outcrop on the top ridge of the island 37
m x 4m (121 ft x 13 ft) wide, 31.61 m (103.7 ft) west of benchmark 9455204 B
2000, 18 m (58 ft) east  of benchmark 9455204 E 2000, 14 m (47 ft) west of
benchmark 9455204 C 2000, and 4 m (12 ft) west of the highest point on the
ridge.  



                         BENCH MARK STAMPING:  9455204 E 2000
                         DESIGNATION:          945 5204 E

MONUMENTATION:           Tidal Station disk                    VM#:        16360
AGENCY:                  Natonal Ocean Service (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 47.4' N (  59.79000)          LONGITUDE: 150°  1.9' W (-150.03200)


The benchmark is a disk set in a rock outcrop on the top ridge of the island 37
m x 4m (121 ft x 13 ft) wide, 49 m (161 ft) WNW of benchmark 9455204 B 2000, 32
m (105 ft) west of benchmark 9455204 C 2000, 21 m (69 ft) west of the highest
point on the ridge, and 18 m (59 ft) west of benchmark 9455204 D 2000.

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

                                                                                
Station ID: 9455204                         PUBLICATION DATE:  04/21/2003
Name:       UPPER NORTHWESTERN FIORD                          
            AK
NOAA Chart: 16682                           Latitude:   59° 47.4' N (  59.79000)
USGS Quad:  SELDOVIA (D-1)                  Longitude: 150°  1.9' W (-150.03200)


                            T I D A L   D A T U M S 


Tidal datums at UPPER NORTHWESTERN FIORD based on:

     LENGTH OF SERIES:      1 Month
     TIME PERIOD:           August 2000 - August 2000
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9455090 SEWARD, RESURRECTION BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  3.303
     MEAN HIGH WATER                            MHW    =  3.031
     MEAN SEA LEVEL                             MSL    =  1.729
     MEAN TIDE LEVEL                            MTL    =  1.722
     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

     9455204 A 2000                              4.905    1.874
     9455204 B 2000                              9.276    6.245
     9455204 C 2000                             12.008    8.977
     9455204 D 2000                             13.212   10.181
     9455204 E 2000                             11.333    8.302


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

                                                                                
Station ID: 9455204                         PUBLICATION DATE:  04/21/2003
Name:       UPPER NORTHWESTERN FIORD                          
            AK
NOAA Chart: 16682                           Latitude:   59° 47.4' N (  59.79000)
USGS Quad:  SELDOVIA (D-1)                  Longitude: 150°  1.9' W (-150.03200)


                             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 9455204 UPPER NORTHWESTERN FIORD, AK

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