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National Ocean Service
Datums Page Page 1 of 5
Station ID: 9455145 PUBLICATION DATE: 04/21/2003
Name: NORTH AIALIK
AK
NOAA Chart: 16682 Latitude: 59° 57.2' N ( 59.95330)
USGS Quad: BLYING SOUND (D-8) Longitude: 149° 42.9' W (-149.71500)
To reach the tidal benchmarks from Seward via boat, proceed 15 km (8 nm) SSE
along Resurrection Bay to Calisto Head, then 32.5 km (17.6 nm) south along
Resurrection Bay to Aialik Cape, then 10.8 km (5.8 nm) WNW along Aialik Bay to
the center of Aialik Bay, then 15.2 km (8.2 nm) north along Aialik Bay to the
north side of Aialik Sill, then 8.7 km (4.7 nm) NNW to the tide station located
east of the eastern most channel of a braided stream. The benchmarks are located
along the shoreline and along a rock wall west of the westernmost channel of a
braided stream. The tide station was located near benchmark 9455145 E 2000 east
of the easternmost channel of a braided stream.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9455145 B 2000
DESIGNATION: 945 5145 B
MONUMENTATION: Tidal Station disk VM#: 16398
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 59° 57.4' N ( 59.95670) LONGITUDE: 149° 43.4' W (-149.72300)
The primary benchmark is a disk set on a sloping rock outcrop, 472 m (1549 ft)
west of benchmark 5145 E 2000, 52 m (171 ft) south of benchmark 9455145 D 2000,
13.20 m (43.3 ft) NNW of benchmark 9455145 A 2000, 3 m (10 ft) south of the west
edge of a creek, and approximately 2 m (8 ft) above the creek.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9455145 PUBLICATION DATE: 04/21/2003
Name: NORTH AIALIK
AK
NOAA Chart: 16682 Latitude: 59° 57.2' N ( 59.95330)
USGS Quad: BLYING SOUND (D-8) Longitude: 149° 42.9' W (-149.71500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9455145 A 2000
DESIGNATION: 945 5145 A
MONUMENTATION: Tidal Station disk VM#: 16397
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 59° 57.3' N ( 59.95500) LONGITUDE: 149° 43.4' W (-149.72300)
The benchmark is a disk set in a rock outcropping protruding from a slate rock
beach and covered at mid-tide, 66 m (217 ft) south of benchmark 9455145 D 2000,
13.20 m (43.3 ft) SSE of benchmark 9455145 B 2000, and 1 m (3 ft) above the
slate rock beach.
BENCH MARK STAMPING: 9455145 C 2000
DESIGNATION: 945 5145 C
MONUMENTATION: Tidal Station disk VM#: 16399
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 59° 57.4' N ( 59.95670) LONGITUDE: 149° 43.4' W (-149.72300)
The benchmark is a disk set vertically on a rock face, 46 m (151 ft) north of
benchmark 9455145 A 2000, 34 m (112 ft) north of benchmark 9455145 B 2000, 26 m
(85 ft) north of a small waterfall, 26 m (85 ft) SW of benchmark 9455145 D 2000,
and 1 m (3 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9455145 PUBLICATION DATE: 04/21/2003
Name: NORTH AIALIK
AK
NOAA Chart: 16682 Latitude: 59° 57.2' N ( 59.95330)
USGS Quad: BLYING SOUND (D-8) Longitude: 149° 42.9' W (-149.71500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9455145 D 2000
DESIGNATION: 945 5145 D
MONUMENTATION: Tidal Station disk VM#: 16400
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 59° 57.4' N ( 59.95670) LONGITUDE: 149° 43.4' W (-149.72300)
The benchmark is a disk set on top of a boulder protruding from the side of a
hill, 66m (217 ft) north of benchmark 9455145 A 2000, 52 m (171 ft) north of
benchmark 9455145 B 2000, 49 m (161 ft) NE of a waterfall, 26 m (85 ft) NE of
benchmark 9455145 C 2000, and 1 m (3 ft) above the ground.
BENCH MARK STAMPING: 9455145 E 2000
DESIGNATION: 945 5145 E
MONUMENTATION: Tidal Station disk VM#: 16401
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 59° 57.3' N ( 59.95500) LONGITUDE: 149° 42.9' W (-149.71500)
The benchmark is a stainless steel rod point located 472 m (1549 ft) east of
benchmark 9455145 B 2000, 18 m (59 ft) east of the east edge of the eastern most
channel of a braided creek, 17 m (56 ft) north of the top of the beach berm and
vegetation line, 10 m (33 ft) south of an alder line, 6 m (20 ft) south of the
tide house, and 1 m (3 ft) ESE of the center of a 1 m (3 ft) high rock cairn.
The datum point is set 6 cm (0.2 ft) below ground, being the top of a 9/16 inch
stainless steel rod driven 2 m (6 ft) to refusal, and encased in a 6.5 inch PVC
pipe with 7.25 inch NOS logo cover set 0.06 m (0.2 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9455145 PUBLICATION DATE: 04/21/2003
Name: NORTH AIALIK
AK
NOAA Chart: 16682 Latitude: 59° 57.2' N ( 59.95330)
USGS Quad: BLYING SOUND (D-8) Longitude: 149° 42.9' W (-149.71500)
T I D A L D A T U M S
Tidal datums at NORTH AIALIK based on:
LENGTH OF SERIES: 1 Month
TIME PERIOD: July 2000 - July 2000
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9455090 SEWARD, RESURRECTION BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 3.237
MEAN HIGH WATER MHW = 2.962
MEAN TIDE LEVEL MTL = 1.686
MEAN SEA LEVEL MSL = 1.685
MEAN LOW WATER MLW = 0.410
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
9455145 B 2000 5.633 2.671
9455145 A 2000 3.168 0.206
9455145 C 2000 6.896 3.934
9455145 D 2000 6.798 3.836
9455145 E 2000 4.601 1.639
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9455145 PUBLICATION DATE: 04/21/2003
Name: NORTH AIALIK
AK
NOAA Chart: 16682 Latitude: 59° 57.2' N ( 59.95330)
USGS Quad: BLYING SOUND (D-8) Longitude: 149° 42.9' W (-149.71500)
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.