U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9467124 PUBLICATION DATE: 03/19/2021
Name: KUN RIVER, SCAMMON BAY
AK
NOAA Chart: 16240 Latitude: 61° 50.5' N ( 61.84170)
USGS Quad: HOOPER BAY D-2 Longitude: 165° 34.0' W (-165.56700)
To reach the tide station from the airport in Scammon Bay, proceed WNW along the
shoulder of runway 10/28 for 222 m (728.3 ft) to the end of the runway
threshold. Then turn right and proceed ENE along the bank of the Kun River for
289 m (948.2 ft) to the tide station. The tidal bench marks are located along
the shore of Kun River near the tide station and New Rd leading into Scammon
Bay.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7124 A 2020
DESIGNATION: 946 7124 A
MONUMENTATION: Flange-encased Rod VM#: 23525
AGENCY: National Ocean Service IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBHB52
LATITUDE: 61° 50.9' N ( 61.84775) LONGITUDE: 165° 34.7' W (-165.57853)
The primary bench mark is a flange encased rod set on an 8 m (26.2 ft) diameter
knoll, 265.2 m (870.1 ft) NE of the north corner of the airstrip threshold,
142.3 m (466.9 ft) north of an airport windsock and 8.86 m (29.1 ft) SSE of the
riverbank. The datum point is set 5 cm (2 inches) below ground level, being the
top of a 9/16 inch stainless steel rod driven 7.0 m (23.0 ft) to refusal, in a
sleeve extending 0.9 m (3.0 ft) and encased in a 7-inch (18 cm) NOS logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9467124 PUBLICATION DATE: 03/19/2021
Name: KUN RIVER, SCAMMON BAY
AK
NOAA Chart: 16240 Latitude: 61° 50.5' N ( 61.84170)
USGS Quad: HOOPER BAY D-2 Longitude: 165° 34.0' W (-165.56700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7124 B 2020
DESIGNATION: 946 7124 B
MONUMENTATION: Flange-encased Rod VM#: 23526
AGENCY: National Ocean Service IDB PID:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBHB51
LATITUDE: 61° 50.6' N ( 61.84336) LONGITUDE: 165° 34.9' W (-165.58225)
The bench mark is a flange encased rod set 48.95 m (160.6 ft) west of a metal
communications tower, 6.96 m (22.8 ft) ENE of new road, 3.95 m (13.0 ft) NE of
the NW corner of a chain link fence enclosing a fuel tank farm and 0.95 m (3.1
ft) SW of the edge of a 15 cm (6 inches) wooden utility pole. The datum point
is set 6 cm (2 inches) below ground level, being the top of a 9/16 inch
stainless steel rod driven 8.2 m (26.9 ft) to refusal, in a sleeve extending 0.9
m (3.0 ft) and encased in a 7-inch (18 cm) NOS logo cover.
BENCH MARK STAMPING: 7124 C 2020
DESIGNATION: 946 7124 C
MONUMENTATION: See descriptive text VM#: 23527
AGENCY: National Ocean Service IDB PID:
SETTING CLASSIFICATION: Driven steel I-beam OPUS PID:
LATITUDE: 61° 50.8' N ( 61.84619) LONGITUDE: 165° 35.1' W (-165.58581)
The bench mark is a filed mark in a steel I-beam structure protecting a fuel
pipeline header, 368.1 m (1207.7 ft) WSW of an airport windsock, 47.42 m (155.6
ft) NE of the confluence of a small slough with the Kun River, 5.68 m (18.6 ft)
SSE of the rip-rap edge of the river bank and 1.80 m (5.9 ft) above ground
level. The datum surface is marked with a punched x and stamping is on the
vertical face of the I-beam structure.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9467124 PUBLICATION DATE: 03/19/2021
Name: KUN RIVER, SCAMMON BAY
AK
NOAA Chart: 16240 Latitude: 61° 50.5' N ( 61.84170)
USGS Quad: HOOPER BAY D-2 Longitude: 165° 34.0' W (-165.56700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7124 D 2020
DESIGNATION: 946 7124 D
MONUMENTATION: Tidal Station disk VM#: 23528
AGENCY: National Ocean Service IDB PID:
SETTING CLASSIFICATION: Boulder OPUS PID:
LATITUDE: 61° 50.6' N ( 61.84325) LONGITUDE: 165° 35.1' W (-165.58519)
The bench mark is a NOS brass disk set in an embedded boulder 18.11 m (59.4 ft)
NNW of a dirt road, 14.53 m (47.7 ft) north of the north end of a corrugated
metal culvert running under a dirt road and 10.05 m (33.0 ft) WSW of the NW
corner of the Maryann Sundown Community Service Center. The datum surface is
set flush with the boulder and 0.57 m (1.9 ft) above ground level.
BENCH MARK STAMPING: 7124 E 2020
DESIGNATION: 946 7124 E
MONUMENTATION: Tidal Station disk VM#: 23529
AGENCY: National Ocean Service IDB PID:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 61° 50.4' N ( 61.84025) LONGITUDE: 165° 34.3' W (-165.57139)
The bench mark is a NOS brass disk set in a granite bedrock outcrop 52.42 m
(172.0 ft) south of the SW corner of a blue house with brown trim, 36.11 m
(118.5 ft) south of a dirt road leading to the school building and 31.32 m
(102.8 ft) SSE of the edge of a wooden utility pole.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9467124 PUBLICATION DATE: 03/19/2021
Name: KUN RIVER, SCAMMON BAY
AK
NOAA Chart: 16240 Latitude: 61° 50.5' N ( 61.84170)
USGS Quad: HOOPER BAY D-2 Longitude: 165° 34.0' W (-165.56700)
T I D A L D A T U M S
Tidal datums at KUN RIVER, SCAMMON BAY based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: August 2020 - September 2020
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9459881 KING COVE, DEER PASSAGE, PACIFIC OCEAN
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.970
MEAN HIGH WATER MHW = 1.735
MEAN TIDE LEVEL MTL = 1.001
MEAN SEA LEVEL MSL = 0.974
MEAN LOW WATER MLW = 0.267
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.094
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7124 A 2020 3.208 1.473
7124 B 2020 3.437 1.702
7124 C 2020 4.676 2.941
7124 D 2020 2.830 1.095
7124 E 2020 20.482 18.747
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9467124 PUBLICATION DATE: 03/19/2021
Name: KUN RIVER, SCAMMON BAY
AK
NOAA Chart: 16240 Latitude: 61° 50.5' N ( 61.84170)
USGS Quad: HOOPER BAY D-2 Longitude: 165° 34.0' W (-165.56700)
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.