U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 9469854 PUBLICATION DATE: 05/28/2004
Name: SHISHMAREF INLET 2
AK
NOAA Chart: 16005 Latitude: 66° 15.8' N ( 66.26330)
USGS Quad: SHISHMAREF (B-3) Longitude: 166° 1.2' W (-166.02000)
To reach the tidal bench marks by boat from Shishmaref, proceed 3 km (2 mi) ENE
from the boat launch area south of the Shishmaref School and continue across the
channel east of Sarichef Island to a small bight in the opposite shoreline. The
bench marks are located 70 m (230 ft) inland of the shoreline. The tide gauge
was established between bench marks 9854 A 2003 and 9854 B 2003 in a Rubbermaid
shed.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING:
DESIGNATION: 946 9854 B
MONUMENTATION: Flange-encased Rod VM#: 17425
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID#: BBBH56
LATITUDE: 66° 15.8' N ( 66.26330) LONGITUDE: 166° 1.2' W (-166.02000)
The primary bench mark is located on a sandy tundra ridge 0.5 m (2 ft) high
running NNW/SSE, 109.43 m (359.0 ft) NNW (339 magnetic) of bench mark 9854 A,
96.60 m (316.9 ft) south (185 magnetic) of bench mark 9854 C, 72 m (236 ft) ENE
(67 magnetic) of the edge of the water in the channel, 60 m (197 ft) ENE (67
magnetic) of the edge of the vegetation along the sand beach, and NE (55
magnetic) of the Shishmaref Navigation Aid Light. The bench mark is set 12 cm
(0.4 ft) below grade, being the top of a rounded off stainless steel rod with
punch mark driven 6.1 m (20 ft) to refusal, and encased in a 0.18 m (0.6 ft)
diameter NGS Geodetic Control Mark logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 9469854 PUBLICATION DATE: 05/28/2004
Name: SHISHMAREF INLET 2
AK
NOAA Chart: 16005 Latitude: 66° 15.8' N ( 66.26330)
USGS Quad: SHISHMAREF (B-3) Longitude: 166° 1.2' W (-166.02000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 946 9854 A
MONUMENTATION: Flange-encased Rod VM#: 17426
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 66° 15.8' N ( 66.26330) LONGITUDE: 166° 1.2' W (-166.02000)
The bench mark is located at the southerly end of a sandy tundra ridge 0.5 m (2
ft) high running NNW/SSE, 109.43 m (359.0 ft) SSE (159 magnetic) of bench mark
9854 B, 63 m (208 ft) ENE (65 magnetic) of the edge of the water in the
channel, 56 m (184 ft) ENE (65 magnetic) of the edge of the vegetation along
the sand beach, and ENE (60 magnetic) of the Shishmaref Navigation Aid Light.
The bench mark is set 7 cm (0.2 ft) below grade, being the top of a rounded off
stainless steel rod with punch mark driven 6.1 m (20 ft) to refusal, and encased
in a 0.18 m (0.6 ft) diameter NGS Geodetic Control Mark logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 9469854 PUBLICATION DATE: 05/28/2004
Name: SHISHMAREF INLET 2
AK
NOAA Chart: 16005 Latitude: 66° 15.8' N ( 66.26330)
USGS Quad: SHISHMAREF (B-3) Longitude: 166° 1.2' W (-166.02000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 946 9854 C
MONUMENTATION: Flange-encased Rod VM#: 17427
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 66° 15.9' N ( 66.26500) LONGITUDE: 166° 1.2' W (-166.02000)
The bench mark is located on a small tundra rise, 132 m (435 ft) ENE (59
magnetic) of the edge of vegetation along the sand beach, 100.65 m (330.2 ft)
SSE (155 magnetic) of bench mark 946 9854 D, 96.60 m (316.9 ft) north (5
magnetic) of bench mark 946 9854 B, and NE (50 magnetic) of the Shishmaref
Navigation Aid Light. The bench mark is set 6 cm (0.2 ft) below grade, being
the top of a rounded off stainless steel rod with punch mark driven 8.5 m (28
ft) to refusal, and encased in a 0.18 m (0.6 ft) diameter NGS Geodetic Control
Mark logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 9469854 PUBLICATION DATE: 05/28/2004
Name: SHISHMAREF INLET 2
AK
NOAA Chart: 16005 Latitude: 66° 15.8' N ( 66.26330)
USGS Quad: SHISHMAREF (B-3) Longitude: 166° 1.2' W (-166.02000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 946 9854 D
MONUMENTATION: Flange-encased Rod VM#: 17428
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 66° 15.9' N ( 66.26500) LONGITUDE: 166° 1.3' W (-166.02200)
The bench mark is located on a small tundra rise, 147.59 m (484.2 ft) SSE (164
magnetic) of bench mark 946 9854 E, 122 m (400 ft) ENE (75 magnetic) of the
edge of vegetation at a 2m (7 ft) high bluff along the sand beach, 100.65 m
(330.2 ft) NNW (335 magnetic) of bench mark 946 9854 C, and NE (47 magnetic)
of the Shishmaref Navigation Aid Light. The bench mark is set 8 cm (0.3 ft)
below grade, being the top of a rounded off stainless steel rod with punch mark
driven 7.3 m (24 ft) to refusal, and encased in a 0.18 m (0.6 ft) diameter NGS
Geodetic Control Mark logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 9469854 PUBLICATION DATE: 05/28/2004
Name: SHISHMAREF INLET 2
AK
NOAA Chart: 16005 Latitude: 66° 15.8' N ( 66.26330)
USGS Quad: SHISHMAREF (B-3) Longitude: 166° 1.2' W (-166.02000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 946 9854 E
MONUMENTATION: Flange-encased Rod VM#: 17429
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod in sleeve OPUS PID:
LATITUDE: 66° 16.0' N ( 66.26670) LONGITUDE: 166° 1.3' W (-166.02200)
The bench mark is located on a circular tundra rise, 147.59 m (484.2 ft) NNW
(344 magnetic) of bench mark 946 9854 D, 70 m (230 ft) SE (125 magnetic) of
the edge of vegetation along the sandy beach, 49 m (161 ft) SE (125 magnetic)
of the top of the closest grass covered sand dune which is approximately 2 m (7
ft) high and is part of the second set of dunes set back from the beach, and NE
(41 magnetic) of the Shishmaref Navigation Aid Light. The bench mark is set 3
cm (0.1 ft) below grade, being the top of a rounded off stainless steel rod with
punch mark driven 21.9 m (72 ft) to refusal, and encased in a 0.18 m (0.6 ft)
diameter NGS Geodetic Control Mark logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 9469854 PUBLICATION DATE: 05/28/2004
Name: SHISHMAREF INLET 2
AK
NOAA Chart: 16005 Latitude: 66° 15.8' N ( 66.26330)
USGS Quad: SHISHMAREF (B-3) Longitude: 166° 1.2' W (-166.02000)
T I D A L D A T U M S
Tidal datums at SHISHMAREF INLET 2 based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: September 2003 - September 2003
TIDAL EPOCH:
CONTROL TIDE STATION: 9491253 KIVALINA
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.314
MEAN HIGH WATER MHW = 0.265
MEAN SEA LEVEL MSL = 0.156
MEAN TIDE LEVEL MTL = 0.149
MEAN LOW WATER MLW = 0.033
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
946 9854 B 1.942 1.677
946 9854 A 2.016 1.751
946 9854 C 1.902 1.637
946 9854 D 2.058 1.793
946 9854 E 2.091 1.826
Foot Notes:
Tidal Datums for Shishmaref Inlet 2, located in northwest Alaska, were computed
from a monthly mean comparison with Kivalina, AK which is not presently referred
to a 19 year National Tidal Datum Epoch (NTDE).
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 9469854 PUBLICATION DATE: 05/28/2004
Name: SHISHMAREF INLET 2
AK
NOAA Chart: 16005 Latitude: 66° 15.8' N ( 66.26330)
USGS Quad: SHISHMAREF (B-3) Longitude: 166° 1.2' W (-166.02000)
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.