U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9466931 PUBLICATION DATE: 10/14/2011
Name: DALL POINT, HOOPER BAY
AK
NOAA Chart: 16304 Latitude: 61° 31.9' N ( 61.53170)
USGS Quad: HOOPER BAY (C-4) Longitude: 166° 8.9' W (-166.14800)
To reach the tidal bench marks, from the south end of the airstrip in Hooper
Bay, proceed west 0.3 km (0.2 mi) through the single row of dunes to the beach,
turn right and proceed north 1.3 km (0.8 mi) along the beach to the slough, turn
right and proceed east 0.3 km (0.2 mi) along Agulikutaq Slough past the tied-up
boats to a grassy area on the south side of the slough. The bench marks are
located along the north and east shoreline of the first pond east of the open
ocean.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 6931 A 2007
DESIGNATION: 946 6931 A
MONUMENTATION: Tidal Station disk VM#: 18463
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 61° 31.8' N ( 61.53000) LONGITUDE: 166° 8.9' W (-166.14800)
The primary bench mark is a flanged encased rod located NE of the end of the
Hooper Bay runway on the south side of the Agulikutaq Slough, 71.50 m (234.6 ft)
west of bench mark 946 6931 B, 67.0 m (220 ft) east of a lifecoat hanger box at
the north edge of the sand dunes, 28.29 m (92.8 ft) south of the south edge of
vegetation along the slough, and 18.0 m (59.1 ft) north of the southern edge of
vegetation along the northern edge of the first pond east of the open ocean.
The bench mark is set 11 cm (0.4 ft) below grade, being the top of a stainless
steel rod driven 12.1 m (39.7 ft) to refusal, and encased in a 8-inch PVC pipe
with NOS logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9466931 PUBLICATION DATE: 10/14/2011
Name: DALL POINT, HOOPER BAY
AK
NOAA Chart: 16304 Latitude: 61° 31.9' N ( 61.53170)
USGS Quad: HOOPER BAY (C-4) Longitude: 166° 8.9' W (-166.14800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6931 B 2007
DESIGNATION: 946 6931 B
MONUMENTATION: Tidal Station disk VM#: 18464
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBBF18
LATITUDE: 61° 31.8' N ( 61.53000) LONGITUDE: 166° 8.9' W (-166.14800)
The bench mark is a flanged-encased rod located NE of the end of the Hooper Bay
runway on the south side of the Agulikutaq Slough, 83.50 m (274.0 ft) WNW of
bench mark 946 6931 C, 71.50 m (234.6 ft) east of bench mark 946 6931 A, 33.71 m
(110.6 ft) south of the north edge of vegetation and the south edge of the
Agulikutaq Tidal Slough, and 24.0 m (78.7 ft) north of the south edge of
vegetation along the north edge of the first pond east of the open ocean. The
bench mark is set 10 cm (0.3 ft) below grade, being the top of a stainless steel
rod driven 9.45 m (31.0 ft) to refusal, and encased in a 8-inch PVC pipe with
NOS logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9466931 PUBLICATION DATE: 10/14/2011
Name: DALL POINT, HOOPER BAY
AK
NOAA Chart: 16304 Latitude: 61° 31.9' N ( 61.53170)
USGS Quad: HOOPER BAY (C-4) Longitude: 166° 8.9' W (-166.14800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6931 C 2007
DESIGNATION: 946 6931 C
MONUMENTATION: Tidal Station disk VM#: 18465
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBFB76
LATITUDE: 61° 31.8' N ( 61.53000) LONGITUDE: 166° 8.8' W (-166.14700)
The bench mark is a flanged-encased rod located NE of the end of the Hooper Bay
runway on the south side of the Agulikutaq Slough, 144 m (274 ft) NNE of bench
mark 946 6931 D, 83.50 m (274.0 ft) ESE of bench mark 946 6931 B, 48.0 m (78.7
ft) NE of the edge of the first pond east of the open ocean, and 38.9 m (127.6
ft) west of Kwigilluchuk Creek which runs north to the Agulikutaq Tidal Slough.
The bench mark is set 8 cm (0.3 ft) below grade, being the top of a stainless
steel rod driven 8.53 m (28.0 ft) to refusal, and encased in a 8-inch PVC pipe
with NOS logo cover.
BENCH MARK STAMPING: 6931 E 2007
DESIGNATION: 946 6931 E
MONUMENTATION: Tidal Station disk VM#: 18466
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 61° 31.7' N ( 61.52830) LONGITUDE: 166° 8.8' W (-166.14700)
The bench mark is a flanged encased rod located NE of the end of the Hooper Bay
runway on the south side of the Agulikutaq Slough, 92.60 m (303.8 ft) SSW of
bench mark 946 6931 D, 58.0 m (190.3 ft) south of the south edge of the first
pond east of the open ocean, and 17.0 m (55.8 ft) north of the north edge of a
different pond. The bench mark is set 3 cm (0.1 ft) below grade, being the top
of a stainless steel rod driven 13.34 m (43.75 ft) to refusal, and encased in a
8-inch PVC pipe with NOS logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9466931 PUBLICATION DATE: 10/14/2011
Name: DALL POINT, HOOPER BAY
AK
NOAA Chart: 16304 Latitude: 61° 31.9' N ( 61.53170)
USGS Quad: HOOPER BAY (C-4) Longitude: 166° 8.9' W (-166.14800)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6931 D 2007
DESIGNATION: 946 6931 D
MONUMENTATION: Tidal Station disk VM#: 18467
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBFB77
LATITUDE: 61° 31.7' N ( 61.52830) LONGITUDE: 166° 8.8' W (-166.14700)
The bench mark is a flanged encased rod located NE of the end of the Hooper Bay
runway on the south side of the Agulikutaq Slough, 144 m (274 ft) SSW of bench
mark 946 6931 C, 92.60 m (303.8 ft) NNE of bench mark 946 6931 E, 34.0 m (111.5
ft) NW of west edge of Kwigilluchuk Creek which runs north to the Agulikutaq
Tidal Slough, and 20.5 m (67.3 ft) east of the east edge of the first pond east
of the open ocean. The bench mark is set 10 cm (0.3 ft) below grade, being the
top of a stainless steel rod driven 13.26 m (43.5 ft) to refusal, and encased in
a 8-inch PVC pipe with NOS logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9466931 PUBLICATION DATE: 10/14/2011
Name: DALL POINT, HOOPER BAY
AK
NOAA Chart: 16304 Latitude: 61° 31.9' N ( 61.53170)
USGS Quad: HOOPER BAY (C-4) Longitude: 166° 8.9' W (-166.14800)
T I D A L D A T U M S
Tidal datums at DALL POINT, HOOPER BAY based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: July 2007 - August 2007
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.358
MEAN HIGH WATER MHW = 1.143
MEAN TIDE LEVEL MTL = 0.628
MEAN SEA LEVEL MSL = 0.561
MEAN LOW WATER MLW = 0.113
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
6931 A 2007 2.279 1.136
6931 B 2007 2.016 0.873
6931 C 2007 1.885 0.742
6931 E 2007 2.249 1.106
6931 D 2007 1.933 0.790
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9466931 PUBLICATION DATE: 10/14/2011
Name: DALL POINT, HOOPER BAY
AK
NOAA Chart: 16304 Latitude: 61° 31.9' N ( 61.53170)
USGS Quad: HOOPER BAY (C-4) Longitude: 166° 8.9' W (-166.14800)
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.