U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
To reach the bench marks from the Unalakleet Airport, travel NE on Airport Road
0.1 km (0.1 mi) to Main Road, turn right and continue SE 0.9 km (0.6 mi) to C
Street, turn left and proceed east 0.1 km (0.1 mi) to the end of the road
terminating at Norton Sound Seafood Plant. The bench marks are located at the
southern end of the town near the mouth of Unalakleet River and along Main Road.
The tide gauge and staff were located on between the two southernmost cells of
the Norton Sound Seafood Plant sheet pile dock.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8333 H 2011
DESIGNATION: 946 8333 H
MONUMENTATION: Metal Rod VM#: 20140
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBCK34
LATITUDE: 63° 52.2' N ( 63.87058) LONGITUDE: 160° 47.1' W (-160.78531)
The primary bench mark is a metal rod driven into the grass NE of the
intersection of River and Main Road at the southernmost point of Unalakleet,
73.62 m (241.3 ft) east of power pole #S1, 61.02 m (200.2 ft) SE of the stop
sign at the end of Main Road, 35.61 m (116.8 ft) SE of the centerline at the end
of the pavement of Main Road, 11.54 m (37.9 ft) north of northern edge of the
chain link/stone erosion abatement, and 0.62 m (2.0 ft) south of an orange
Carsonite witness post. The datum point is 14 cm (0.5 ft) below grade, being the
top of a stainless rod driven 18.3 m (60 ft) to refusal with a 0.90 m (3.0 ft)
grease filled sleeve and encased in a 6-inch PVC pipe with concrete kickblock
with an NOS logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8333 F 2011
DESIGNATION: 946 8333 F
MONUMENTATION: Bench Mark disk VM#: 20137
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 63° 52.3' N ( 63.87142) LONGITUDE: 160° 47.1' W (-160.78506)
The bench mark is a disk set flush in the concrete pad of Norton Sound Seafood
Plant's storage building on the north side of overhead door located west of main
building, 36.70 m (120.4 ft) south of the centerline of C Street, 34.15 m (112.0
ft) west of the center of the largest overhead door of the plant's main
building, 6.15 m (20.2 ft) north of the SE corner of the plant's storage
building, 3.04 m (10.0 ft) south of the NE corner of the plant's storage
building, 0.27 m (0.9 ft) south of the north edge of the concrete, and 0.11 m
(0.4 ft) west of the eastern edge of the concrete.
BENCH MARK STAMPING: 8333 E 2011
DESIGNATION: 946 8333 E
MONUMENTATION: Bench Mark disk VM#: 20138
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID#: BBDH09
LATITUDE: 63° 52.3' N ( 63.87142) LONGITUDE: 160° 47.0' W (-160.78406)
The bench mark is a disk set flush in the concrete pad of Norton Sound Seafood
Plant's sheet pile dock on the west side near the driveway of the parking lot,
15.95 m (52.3 ft) east of the NE corner of Norton Sounds main building, 9.60 m
(31.5 ft) west of the round base of Norton Sound's loading crane, 6.20 m (20.3
ft) north of the southernmost base of a round sheet pile cell where it meets a
chain link/stone erosion abatement, and 0.28 m (0.9 ft) east of the western edge
of the concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8333 G 2011
DESIGNATION: 946 8333 G
MONUMENTATION: Bench Mark disk VM#: 20139
AGENCY: National Ocean Service (NOS) IDB PID:
SETTING CLASSIFICATION: Concrete pad OPUS PID#: BBDH10
LATITUDE: 63° 52.5' N ( 63.87461) LONGITUDE: 160° 47.4' W (-160.78983)
The bench mark is a disk set flush in the concrete pad of the United States
Postal Office's flagpole on the NE side of Main Road, 19.31 m (63.4 ft) SSE of
power and light pole #7, 12.50 m (41.0 ft) NNW of the SW corner of the USPS,
11.11 m (36.5 ft) east of the centerline of Main Road, 2.52 m (8.3 ft) west of
west wall of USPS, 0.25 m (0.8 ft) SW of the flag pole center, and 0.10 m (0.3
ft) above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: UNALAKLEET NO 1
DESIGNATION: UNALAKLEET NO 1
MONUMENTATION: Tidal Station disk VM#: 22017
AGENCY: US Coast & Geodetic Survey IDB PID:
SETTING CLASSIFICATION: Concrete stairs OPUS PID:
LATITUDE: 63° 52.3' N ( 63.87175) LONGITUDE: 160° 47.2' W (-160.78739)
The benchmark is a disk set flush in the East concrete stair on the South side
of the old native school. 23.86 m (78.3 ft) NE of power pole topped with
transformer number 2302, 23.00 m (75.5 ft) East of the East edge of pavement of
second street at the extended centerline of F street, 11.57 m (38.0 ft) West of
the SE corner of old school building, 1.00 m (3.3 ft) WSW of hinge of single man
door on South side of old school building, 0.20 m (0.7 ft) West of the E edge of
concrete and 0.48 m (1.6 ft) above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: UNK A
DESIGNATION: UNK A
MONUMENTATION: Flange-encased Rod VM#: 22824
AGENCY: R&M Consultants, Inc. IDB PID#: DM4448
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: DM4448
LATITUDE: 63° 53.6' N ( 63.89389) LONGITUDE: 160° 48.1' W (-160.80139)
The bench mark is a stainless steel rod driven to refusal 143.3 m (470 ft) SSE
of a windsock, 68 m (223 ft) NE of a runway light on the east side of Runway 15,
and 0.43 m (1.4 ft) south of a Carsonite witness post. The mark is driven to a
refusal depth of 11 m (36 ft) and is the top of a 1.43 cm (9/16 in) stainless
steel rod with 1 m (3.3 ft) long grease-filled fin sleeve and bedded in sand.
The mark is surrounded within a 15 cm (6 in) diameter PVC pipe with an 18.2 cm
(7 in) aluminum logo cover attached and stamped UNK A . This station is
designated a primary airport control station.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: UNK B
DESIGNATION: UNK B
MONUMENTATION: Flange-encased Rod VM#: 22825
AGENCY: R&M Consultants, Inc. IDB PID#: DM4449
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: DM4449
LATITUDE: 63° 53.1' N ( 63.88550) LONGITUDE: 160° 47.8' W (-160.79675)
The bench mark is a stainless steel rod driven to refusal located 133.2 m (437.0
ft) WNW of the AWOS, 34.8 m (114.3 ft) east of a runway light on the east side
of Runway 33, 15 cm (6 in) south of a Carsonite witness post. The bench mark is
driven to a depth of 14.6 m (48 ft) and surrounded by a 0.92 m (3.0 ft) long
grease-filled fin sleeve bedded in sand and surrounded within a 15 cm (6 in)
diameter PVC pipe with a 18.2 cm (7 in) aluminum logo cover attached and stamped
UNK B . This mark is a secondary airport control station.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
T I D A L D A T U M S
Tidal datums at UNALAKLEET based on:
LENGTH OF SERIES: 5 YEARS (Seasonal)
TIME PERIOD: 7-8/11,8-12/16,1,6-7,10,12/17,7-10,12/18,7-8/19
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9468756 NOME, NORTON SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (08/03/2019) = 3.548
MEAN HIGHER HIGH WATER MHHW = 1.051
MEAN HIGH WATER MHW = 0.931
MEAN TIDE LEVEL MTL = 0.509
MEAN SEA LEVEL MSL = 0.473
MEAN LOW WATER MLW = 0.087
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.706
LOWEST OBSERVED WATER LEVEL (11/11/2016) = -0.502
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
8333 H 2011 3.973 3.042
8333 F 2011 4.481 3.550
8333 E 2011 2.678 1.747
8333 G 2011 5.470 4.539
UNALAKLEET NO 1 6.017 5.086
UNK A 5.858 4.927
UNK B 5.380 4.449
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
Foot Notes:
Benchmarks UNK A and UNK B are based on one differential leveling connection and
do not meet the quality control standards of the NOS. Therefore, caution should
be used when deriving elevations for these marks.
This station does not always capture a full range of tide due to local freezing
& shoaling at the station. Datums are computed using ice free months of each
year only.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 9
Station ID: 9468333 PUBLICATION DATE: 05/17/2021
Name: UNALAKLEET
AK
NOAA Chart: 16200 Latitude: 63° 52.5' N ( 63.87500)
USGS Quad: UNALAKLEET D-4 Longitude: 160° 47.3' W (-160.78799)
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.