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Bench Mark Sheet for 9455120, AGNES COVE 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Superseded Epoch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Small blue map location marker Unpublished bench mark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: 9455120                         PUBLICATION DATE:  04/29/2004
Name:       AGNES COVE                                        
            AK
NOAA Chart: 16682                           Latitude:   59° 46.4' N (  59.77330)
USGS Quad:  BLYING SOUND (D-7)              Longitude: 149° 35.3' W (-149.58800)


To reach the tidal bench marks from Seward, AK, navigate south through
Ressurection Bay for 15.5 km (9.7 mi) to Caines Head, AK, then proceed  26 km
(16 mi) SSW along the shoreline through Ressurection Bay to Agnes Cove, AK.  The
tidal bench marks are located along the beach in the rock outcrop extending SE
portion of the Agnes Cove.  The tide gauge was installed on the beach in the
rock outcrop.


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


                 PRIMARY BENCH MARK STAMPING:  5120 A 2001
                         DESIGNATION:          945 5120 A

MONUMENTATION:           Tidal Station disk                    VM#:        16582
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID#: BBFJ01
LATITUDE:   59° 46.4' N (  59.77330)          LONGITUDE: 149° 35.3' W (-149.58800)


The bench mark is a disk set flush on a 1 m (3 ft) wide sloping granite ledge,
22.70 m (74.5 ft) WNW (300 degrees magnetic) from bench mark 5120 B 2001, and
about 3 m (10 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: 9455120                         PUBLICATION DATE:  04/29/2004
Name:       AGNES COVE                                        
            AK
NOAA Chart: 16682                           Latitude:   59° 46.4' N (  59.77330)
USGS Quad:  BLYING SOUND (D-7)              Longitude: 149° 35.3' W (-149.58800)


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


                         BENCH MARK STAMPING:  5120 B 2001
                         DESIGNATION:          945 5120 B

MONUMENTATION:           Tidal Station disk                    VM#:        16583
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID#: BBFJ08
LATITUDE:   59° 46.4' N (  59.77330)          LONGITUDE: 149° 35.3' W (-149.58800)


The bench mark is a disk set flush on a horizontal granite outcropping, 22.70 m
(74.5 ft) ESE (120 degrees magnetic) from bench mark 5120 A 2001, 14.81 m (48.6
ft) NNW (330 degrees magnetic) from bench mark 5120 C 2001, 3 m (10 ft) SW from
the apparent high water line, and about 4 m (12 ft) above the apparent high
water line.



                         BENCH MARK STAMPING:  5120 C 2001
                         DESIGNATION:          945 5120 C

MONUMENTATION:           Tidal Station disk                    VM#:        16584
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 46.4' N (  59.77330)          LONGITUDE: 149° 35.3' W (-149.58800)


The bench mark is a disk set flush on a horizontal granite outcropping, 17.22 m
(56.5 ft) NNW (340 degrees magnetic) from bench mark 5120 D 2001, 14.81 m (48.6
ft) SE (150 degrees magnetic) from bench mark 5120 B 2001, 14 m (46 ft) south
from a prominent purple rock set in the hillside, 5 m (16 ft) SW from the high
water line, 1 m (4 ft) SW of the edge of the rock ledge in which it is set, and
about 2 m (8 ft) above the apparent high water line.

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

                                                                                
Station ID: 9455120                         PUBLICATION DATE:  04/29/2004
Name:       AGNES COVE                                        
            AK
NOAA Chart: 16682                           Latitude:   59° 46.4' N (  59.77330)
USGS Quad:  BLYING SOUND (D-7)              Longitude: 149° 35.3' W (-149.58800)


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


                         BENCH MARK STAMPING:  5120 D 2001
                         DESIGNATION:          945 5120 D

MONUMENTATION:           Tidal Station disk                    VM#:        16585
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 46.4' N (  59.77330)          LONGITUDE: 149° 35.3' W (-149.58800)


The bench mark is a disk set flush on the highest point of a horizontal granite
outcropping that slopes toward the water, located on the eastern most extent of
the beach, 17.22 m (56.5 ft) SSE (160 degrees magnetic) from bench mark 5120 C
2001, 16.00 m (52.5 ft) north (000 degrees magnetic) from bench mark 5120 E
2001, 1 m (3 ft) east from the vegetation line, and about 3 m (9 ft) above the
apparent high water line.



                         BENCH MARK STAMPING:  5120 E 2001
                         DESIGNATION:          945 5120 E

MONUMENTATION:           Tidal Station disk                    VM#:        16586
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   59° 46.4' N (  59.77330)          LONGITUDE: 149° 35.3' W (-149.58800)


The bench mark is a disk set flush on a flat nook on a granite outcropping,
16.00 m (52.5 ft) south (180 degrees magnetic) from bench mark 5120 E 2001, 3 m
(10 ft) SW from the high water line, 2 m (6 ft) east from the vegetation line,
and about 2 m (8 ft) above the apparent high water line.

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

                                                                                
Station ID: 9455120                         PUBLICATION DATE:  04/29/2004
Name:       AGNES COVE                                        
            AK
NOAA Chart: 16682                           Latitude:   59° 46.4' N (  59.77330)
USGS Quad:  BLYING SOUND (D-7)              Longitude: 149° 35.3' W (-149.58800)


                            T I D A L   D A T U M S 


Tidal datums at AGNES COVE based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           August 2001 - September 2001
     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   =  3.257
     MEAN HIGH WATER                            MHW    =  2.976
     MEAN SEA LEVEL                             MSL    =  1.703
     MEAN TIDE LEVEL                            MTL    =  1.699
     MEAN LOW WATER                             MLW    =  0.421
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     5120 A 2001                                 6.850    3.874
     5120 B 2001                                 6.023    3.046
     5120 C 2001                                 5.581    2.604
     5120 D 2001                                 6.029    3.053
     5120 E 2001                                 4.363    1.386


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

                                                                                
Station ID: 9455120                         PUBLICATION DATE:  04/29/2004
Name:       AGNES COVE                                        
            AK
NOAA Chart: 16682                           Latitude:   59° 46.4' N (  59.77330)
USGS Quad:  BLYING SOUND (D-7)              Longitude: 149° 35.3' W (-149.58800)


                             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 9455120 AGNES COVE, AK

Revised: 08/08/2018
NOAA / National Ocean Service
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