U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
To reach the bench marks from the Wiley Post-Will Rogers Memorial Airport in
Barrow, proceed 0.3 km (0.2 mi) west on Ahkovak Street in front of the airport,
turn right on Kiogak Street and proceed 0.5 km (0.3 mi) north to the
intersection with Eben Hopson Street, turn slightly right and proceed 0.6 km
(0.4 mi) NE on Eben Hopson Street around the NW side of a lagoon, turn left on
Brower Street and proceed north 0.3 km (0.2 mi) to the intersection with
Stevenson Street, turn right and follow Stevenson Street 4.5 km (2.8 mi) NE
along the beach to the Naval Arctic Research Lab (NARL) complex, turn right at a
large sign for Ilisagvik College and meander east 0.3 km (0.2 mi) through the
many old NARL buildings keeping the blue Ilisagvik College building on the
right, continue under the utilidor on the NE side of the Ilisagvik College
building and continue east 0.4 km (0.2 mi) on the gravel access road to the
Barrow Global Climate Change Research Facility (BGCCRF). The bench marks are
chisel marks on the building pilings of the BGCCRF and one bench mark SE of the
facility in the tundra. The tide gauges are underwater pressure sensors located
on anchors 3.5 km (2.2 mi) NW offshore from this facility.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 4935 F 2008
DESIGNATION: 949 4935 F
MONUMENTATION: Not specified (see descriptive text) VM#: 18932
AGENCY: IDB PID#:
SETTING CLASSIFICATION: Chiseled horizontal line in a steel pileOPUS PID:
LATITUDE: 71° 19.5' N ( 71.32472) LONGITUDE: 156° 40.1' W (-156.66772)
The bench mark is a chiseled horizontal line on the side of a pile at the SW
corner of the Barrow Global Climate Change Research Facility building, 36.47 m
(119.6 ft) north of the most northerly power pole at the SW corner of the gravel
pad, 19.66 m (64.5 ft) SE of bench mark 9494935 E, 12.95 m (42.5 ft) SE of the
center of the entrance door, and 11.98 m (39.3 ft) SE of the center of red post
supporting the roof over the entryway. The bench mark is 0.72 m (2.4 ft) above
the level of the gravel pad, and 0.17 m (0.6 ft) below the bottom of the siding
on the building, chiseled into a 0.19 m (0.6 ft) diameter steel pile 8.5 m (28
ft) long set in an augured hole backfilled with slurry.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4935 A 2008
DESIGNATION: 949 4935 A
MONUMENTATION: Not specified (see descriptive text) VM#: 18927
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Chisled arrow in metal pile cap OPUS PID:
LATITUDE: 71° 19.5' N ( 71.32511) LONGITUDE: 156° 40.0' W (-156.66697)
The bench mark is a chiseled arrow in the center of the outside edge of a metal
pile cap on the NE side of the Barrow Global Climate Change Research Facility
building, 16.61 m (54.5 ft) NW of the southern most corner of the power plant,
14.81 m (48.6 ft) SE of bench mark 9494935 B and the north corner of the
expanded metal deck, 4.78 m (15.7 ft) NE of the center a double wide door, 4.33
m (14.2 ft) SE of the center of the utilidor beneath the deck, and 3.16 m (10.4
ft) NW of the SE corner of the expanded metal deck. The bench mark is 1.20 m
(4.3 ft) above the level of the gravel pad, and 0.29 m (1.0 ft) below the top of
the expanded metal deck, chiseled into a metal plate welded to the top of a 0.17
m (0.6 ft) diameter steel pile 7.3 m (24 ft) long set in an augured hole
backfilled with slurry.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4935 B 2008
DESIGNATION: 949 4935 B
MONUMENTATION: Not specified (see descriptive text) VM#: 18928
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Chiseled square in metal pile cap OPUS PID:
LATITUDE: 71° 19.5' N ( 71.32522) LONGITUDE: 156° 40.0' W (-156.66694)
The bench mark is a chiseled square on top of the north corner of a metal pile
cap on the NE side of the Barrow Global Climate Change Research Facility
building, 14.81 m (48.6 ft) NW of bench mark 9494935 A, 13.94 m (45.7 ft) WNW of
the NW corner of the power plant, 11.45 m (37.6 ft) SE of bench mark 9494935 C,
10.52 m (34.5 m) NNW of the center of the utilidor below the deck, 4.17 m (13.7
ft) north of the center of a double wide door, and 1.71 m (3.8 ft) ENE of the
face of the building. The bench mark is 1.00 m (3.3 ft) above the level of the
gravel pad, and 0.30 m (1.0 ft) below the top of the expanded metal deck,
chiseled into a metal plate welded to the top of a 0.17 m (0.6 ft) diameter
steel pile 7.3 m (24 ft) long set in an augured hole backfilled with slurry.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4935 C 2008
DESIGNATION: 949 4935 C
MONUMENTATION: Not specified (see descriptive text) VM#: 18929
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Chiseled square in metal pile cap OPUS PID:
LATITUDE: 71° 19.5' N ( 71.32522) LONGITUDE: 156° 40.0' W (-156.66731)
The bench mark is a chiseled square on top of the SE corner of a metal pile cap
on the NE side of the Barrow Global Climate Change Research Facility building,
23.94 m (78.5 ft) NW of the NW corner of the power plant, 11.45 m (37.6 ft) NW
of bench mark 9494935 B, 8.78 m (28.8 ft) NNW of the center of the door at the
SSE end of the deck, and 2.23 m (7.3 ft) ENE of the face of the building. The
bench mark is 0.85 m (2.8 ft) above the level of the gravel pad, and 0.30 m (1.0
ft) below the top of the expanded metal deck, chiseled into a metal plate welded
to the top of a 0.17 m (0.6 ft) diameter steel pile 7.3 m (24 ft) long set in an
augured hole backfilled with slurry.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4935 D 2008
DESIGNATION: 949 4935 D
MONUMENTATION: Not specified (see descriptive text) VM#: 18930
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Chiseled horizontal line in a steel
pile OPUS PID:
LATITUDE: 71° 19.5' N ( 71.32508) LONGITUDE: 156° 40.1' W (-156.66806)
The bench mark is a chiseled horizontal line on the side of a pile at the NW
corner of the Barrow Global Climate Change Research Facility building, 27.96 m
(91.7 ft) SSW of a wooden light pole on the north edge of the gravel pad, 24.02
m (78.8 ft) NNW of bench mark 9494935 E, and 15.64 m (51.3 ft) ENE of a wooden
power pole along the west edge of the gravel pad. The bench mark is 0.66 m (2.2
ft) above the level of the gravel pad, and 0.13 m (0.4 ft) below the bottom of
the siding on the building, chiseled into a 0.19 m (0.6 ft) diameter steel pile
8.5 m (28 ft) long set in an augured hole backfilled with slurry.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 4935 E 2008
DESIGNATION: 949 4935 E
MONUMENTATION: Not specified (see descriptive text) VM#: 18931
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Chiseled horizontal line in steel pile OPUS PID:
LATITUDE: 71° 19.5' N ( 71.32486) LONGITUDE: 156° 40.1' W (-156.66806)
The bench mark is a chiseled horizontal line on the side of a pile on the SW
side of the Barrow Global Climate Change Research Facility building, 24.02 m
(78.8 ft) SSE of bench mark 9494935 D, 19.66 m (64.5 ft) NW of bench mark
9494935 F, 6.88 m (22.6 ft) NW of the center of the main entrance door, and 1.69
m (5.5 ft) west of a brass fire hose fitting. The bench mark is 0.77 m (2.5 ft)
above the level of the gravel pad, and 0.21 m (0.7 ft) below the bottom of the
siding on the building, chiseled into a 0.19 m (0.6 ft) diameter steel pile 8.5
m (28 ft) long set in an augured hole backfilled with slurry.
BENCH MARK STAMPING: S5253 WCMC L9C3 L8C7 2005
DESIGNATION: 9494935 BLM S5253
MONUMENTATION: Tidal Station disk VM#: 18933
AGENCY: US Bureau of Land Management IDB PID#:
SETTING CLASSIFICATION: Stainless steel post OPUS PID#: BBBG78
LATITUDE: 71° 19.4' N ( 71.32378) LONGITUDE: 156° 39.9' W (-156.66450)
The bench mark is a disk set in the tundra SSE of the Barrow Global Climate
Change Research Facility building and west of a Imikpuk Lake, 156.8 m (514.4 ft)
SSE of bench mark 9494935 F, 92.30 m (302.8 ft) WSW of Imikpuk Lake, 67.94
(222.9 ft) ENE of wooden power pole #19, 43.04 m (141.2 ft) NNE of a 1.5 m (5.0
ft) tall 6-inch by 6-inch wooden post, 34.83 m (114.3 ft) WNW of an aluminum
survey marker stamped "TR100 S5048 2005" set flush in the tundra, and 0.06 m
(0.2 ft) above grade.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
T I D A L D A T U M S
Tidal datums at BARROW OFFSHORE based on:
LENGTH OF SERIES: 1 YEAR
TIME PERIOD: September 2008 - August 2009
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9497645 PRUDHOE BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (12/14/2008) = 0.890
MEAN HIGHER HIGH WATER MHHW = 0.202
MEAN HIGH WATER MHW = 0.166
MEAN SEA LEVEL MSL = 0.094
MEAN TIDE LEVEL MTL = 0.092
MEAN LOW WATER MLW = 0.018
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (01/29/2010) = -0.783
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
4935 F 2008 5.044 4.878
4935 A 2008 5.930 5.764
4935 B 2008 5.928 5.762
4935 C 2008 5.926 5.760
4935 D 2008 5.070 4.904
4935 E 2008 5.011 4.845
S5253 WCMC L9C3 L8C7 2005 1.760 1.594
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 9494935 PUBLICATION DATE: 05/20/2011
Name: BARROW OFFSHORE
AK
NOAA Chart: 16082 Latitude: 71° 21.6' N ( 71.36011)
USGS Quad: BARROW (B-4) Longitude: 156° 43.8' W (-156.72986)
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.