U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9455606 PUBLICATION DATE: 04/09/2018
Name: ANCHOR POINT
AK
NOAA Chart: 16645 Latitude: 59° 46.3' N ( 59.77197)
USGS Quad: SELDOVIA (D-5) Longitude: 151° 52.0' W (-151.86703)
To reach the bench marks from the Anchor Point Post Office, proceed south on the
Sterling Hwy for 0.2 km (0.1 mi) to the Old Sterling Hwy, then SW on the Old
Sterling Hwy for 0.6 km (0.4 mi) crossing the Anchor River Bridge to the
intersection with Anchor Point Road, then west on Anchor Point Rd. for 2.0 km
(1.2 mi) to its termination at the parking lot for the public boat launch, then
south along the beach to 0.6 km (0.4 mi) to the USCG day marker. The bench marks
are on top of the bluff near the day marker. The tide house was located adjacent
to the chain link fence.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BM 4 1973
DESIGNATION: 945 5606 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 9551
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 59° 46.2' N ( 59.76919) LONGITUDE: 151° 52.0' W (-151.86703)
The primary bench mark is a disk set flush in a buried concrete fence post
footing, just outside of the NW corner of the chain link fence surrounding the
USCG navigation light, 6.09 m (20.0 ft) WNW of 945 5606 TIDAL 5, 4.90 m (16.1
ft) ENE of the top edge of the beach bluff, 2.90 m (9.5 ft) ESE of bench mark
945 5606 E, 0.55 m (1.8 ft) NW of NW most corner of the chain link fence and
0.05 m (0.2 ft) below grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9455606 PUBLICATION DATE: 04/09/2018
Name: ANCHOR POINT
AK
NOAA Chart: 16645 Latitude: 59° 46.3' N ( 59.77197)
USGS Quad: SELDOVIA (D-5) Longitude: 151° 52.0' W (-151.86703)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 6 1973
DESIGNATION: 945 5606 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 9553
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 59° 46.1' N ( 59.76897) LONGITUDE: 151° 52.4' W (-151.87333)
The bench mark is set in a 1.06 m x 1.06 m (3.5 ft x 3.5 ft) concrete footing of
the old USCG light in the trees SSE of the new USCG light, 33.17 m (108.8 ft) SE
of bench mark 945 5606 TIDAL 5, 19.91 m (65.3 ft) SE of the eastern most corner
fence post of the chain link fence surrounding the USCG light, 17.10 m (56.1 ft)
ESE of the top edge of the beach bluff, 7.22 m (23.7 ft) ESE of bench mark 945
5606 TIDAL 7, 4.76 m (15.6 ft) NNW of bench mark 945 5606 TIDAL 8, and 0.03 m
(0.1 ft) above the concrete.
BENCH MARK STAMPING: BM 7 1973
DESIGNATION: 945 5606 TIDAL 7
MONUMENTATION: Tidal Station disk VM#: 9554
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 59° 46.1' N ( 59.76897) LONGITUDE: 151° 52.0' W (-151.86686)
The bench mark is set in a 1.06 m x 1.06 m (3.5 ft x 3.5 ft) concrete footing of
the old USCG light in the trees SSE of the new USCG light, 17.89 m (58.7 ft) SSE
of the gate of the chain link fence surrounding the new USCG light, 10.10 m
(33.1 ft) ENE of the top edge of the beach bluff, 9.02 m (29.6 ft) west of bench
mark 945 5606 TIDAL 8, 7.22 m (23.7 ft) WNW of bench mark 945 5606 TIDAL 6, 0.18
m (0.6 ft) east of the western most edge of the concrete footing, and 0.02 m
(0.1 ft) above the concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9455606 PUBLICATION DATE: 04/09/2018
Name: ANCHOR POINT
AK
NOAA Chart: 16645 Latitude: 59° 46.3' N ( 59.77197)
USGS Quad: SELDOVIA (D-5) Longitude: 151° 52.0' W (-151.86703)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 8 1973
DESIGNATION: 945 5606 TIDAL 8
MONUMENTATION: Tidal Station disk VM#: 9555
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID:
LATITUDE: 59° 46.1' N ( 59.76892) LONGITUDE: 151° 52.0' W (-151.86675)
The bench mark is set in a 1.06 m x 1.06 m (3.5 ft x 3.5 ft) concrete footing of
the old USCG light in the trees SSE of the new USCG light, 26.09 m (85.6 ft) SSE
of the gate of the chain link fence surrounding the new USCG light, 17.30 m
(56.8 ft) ENE of the top edge of the beach bluff, 9.02 m (29.6 ft) east of bench
mark 945 5606 TIDAL 7, 0.71 m (2.3 ft) east of the western most edge of concrete
and 0.02 m (0.1 ft) above the concrete.
BENCH MARK STAMPING: 5606 E 1977
DESIGNATION: 945 5606 E
MONUMENTATION: Tidal Station disk VM#: 9556
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footing OPUS PID#: BBBK76
LATITUDE: 59° 46.2' N ( 59.76919) LONGITUDE: 151° 52.0' W (-151.86708)
The bench mark is set flush in a buried 1.06 m x 1.06 m (3.5 ft x 3.5 ft)
concrete footing of the old USCG light NW of the new USCG light, 8.79 m (28.8
ft) WNW of bench mark 945 5606 TIDAL 5, 3.26 m (10.7 ft) WNW of the western most
corner of the chain link fence surrounding the USCG light, 2.90 m (9.5 ft) WNW
of bench mark 945 5606 TIDAL 4, 2.30 m (7.5 ft) ENE of the top edge of the beach
bluff.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9455606 PUBLICATION DATE: 04/09/2018
Name: ANCHOR POINT
AK
NOAA Chart: 16645 Latitude: 59° 46.3' N ( 59.77197)
USGS Quad: SELDOVIA (D-5) Longitude: 151° 52.0' W (-151.86703)
T I D A L D A T U M S
Tidal datums at ANCHOR POINT based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: October 2009 - October 2009
TIDAL EPOCH: 2012-2016
CONTROL TIDE STATION: 9455500 SELDOVIA, COOK INLET
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 5.604
MEAN HIGH WATER MHW = 5.366
MEAN SEA LEVEL MSL = 2.960
MEAN TIDE LEVEL MTL = 2.949
MEAN LOW WATER MLW = 0.532
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
BM 4 1973 12.813 7.447
BM 6 1973 12.461 7.095
BM 7 1973 12.382 7.016
BM 8 1973 12.412 7.046
5606 E 1977 12.734 7.368
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9455606 PUBLICATION DATE: 04/09/2018
Name: ANCHOR POINT
AK
NOAA Chart: 16645 Latitude: 59° 46.3' N ( 59.77197)
USGS Quad: SELDOVIA (D-5) Longitude: 151° 52.0' W (-151.86703)
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.