U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9455934 PUBLICATION DATE: 05/23/2003
Name: PORT MACKENZIE, COOK INLET
ALASKA
NOAA Chart: 16665 Latitude: 61° 16.1' N
USGS Quad: ANCHORAGE (B-8) Longitude: 149° 55.0' W
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 5934 A 2001
DESIGNATION: 945 5934 A
MONUMENTATION: Tidal Station disk VM#: 16611
AGENCY: Terra Surveys, LLC PID:
SETTING CLASSIFICATION: Boulder
The primary bench mark is a disk set flush in a drill hole on the top of a 0.50
m x 0.50 m (1.6 ft x 1.6 ft) boulder almost flush with a sloping beach north of
Port MacKenzie, 91.44 m (300.0 ft) north (10 degrees magnetic) of bench mark
5934 B 2001, 27.01 m (88.6 ft) south of a 0.25m (0.8ft) diameter cottonwood with
a duplex nail 0.73 m (2.4 ft) above ground driven in the east face, 6.40 m (21.0
ft) ESE of a 0.10m (0.3ft) diameter cottonwood with a duplex nail 0.40 m (1.3
ft) above ground driven in the west face, 2.99 m (9.8 ft) N 28 E of a 1 m (3 ft)
diameter boulder with an "X" chiseled on top, and approximately at the high
water line.
BENCH MARK STAMPING: 5934 B 2001
DESIGNATION: 945 5934 B
MONUMENTATION: Tidal Station disk VM#: 16612
AGENCY: Terra Surveys, LLC PID:
SETTING CLASSIFICATION: Boulder
The bench mark is a disk set flush in a drill hole on the top of a 2 m x 1 m x 1
m (5 ft x 4ft x 3 ft) high boulder at the base of a bluff on the beach north of
the Port MacKenzie dock, 101.5 m (333.0 ft) north (7 degrees magnetic) of bench
mark 5934 C 2001, 91.4 m (300.0 ft) south (190 degrees magnetic) of bench mark
5934 A 2001, 7.07 m (23.2 ft) SSW of a 0.76 m x 0.61 m (2.5 ft x 2.0 ft) gray
with white strata boulder with an "X" chiseled on top, and approximately at the
high water line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9455934 PUBLICATION DATE: 05/23/2003
Name: PORT MACKENZIE, COOK INLET
ALASKA
NOAA Chart: 16665 Latitude: 61° 16.1' N
USGS Quad: ANCHORAGE (B-8) Longitude: 149° 55.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5934 C 2001
DESIGNATION: 945 5934 C
MONUMENTATION: Tidal Station disk VM#: 16613
AGENCY: Terra Surveys, LLC PID:
SETTING CLASSIFICATION: Boulder
The bench mark is a disk set flush in a drill hole on the top of a 1 m x 0.5 m
(3 ft x 1.6 ft) boulder almost flush with a sloping beach north of the Port
MacKenzie dock, 101.50 m (333.0 ft) south (187 degrees magnetic) of bench mark
5934 B 2001, 44.62 m (146.4 ft) north of a 1.20 m (3.9 ft) diameter 0.80 m (2.6
ft) high split boulder with an "X" chiseled in the top, 20.51 m (67.3 ft) west
of a prominent 1 m (3 ft) high boulder visible at low tide only, 8.96 m (29.4
ft) SE of a 0.20m (0.7ft) cottonwood leaning towards the beach with a duplex
nail 1 m (3 ft) above ground driven into the north face, and approximately at
the high water line.
BENCH MARK STAMPING: 5934 D 2001
DESIGNATION: 945 5934 D
MONUMENTATION: Metal Rod VM#: 16614
AGENCY: Terra Surveys, LLC. PID:
SETTING CLASSIFICATION: Stainless steel rod
The bench mark is a metal rod rounded at the top located on the east side in
humas duff and trees north of the dock, 154.5 m (507.0 ft) south of bench mark
5934 C 2001, 5.49 m (18.0 ft) NNW of a 1 m x 1 m (2 ft x 3 ft) flat boulder
flush with the beach, 4.54 m (14.9 ft) SSW of a 0.30m (1 ft) cottonwood with a
duplex nail driven into the east face, and 2.87 m (9.4 ft) NW of a 1 m x 1 m (2
ft x 3 ft) flat boulder flush with the beach. The bench mark is driven 3.7 m (12
ft) to the point of refusal and encased in a 5-inch NOS logo cap filled with
gravel with the letter D stamped on the rim surrounded by a 0.24 m (0.8 ft) high
rock mound.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9455934 PUBLICATION DATE: 05/23/2003
Name: PORT MACKENZIE, COOK INLET
ALASKA
NOAA Chart: 16665 Latitude: 61° 16.1' N
USGS Quad: ANCHORAGE (B-8) Longitude: 149° 55.0' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 5934 E 2001
DESIGNATION: 945 5934 E
MONUMENTATION: Tidal Station disk VM#: 16615
AGENCY: Terra Surveys, LLC. PID:
SETTING CLASSIFICATION: Boulder
The bench mark is a disk set flush in a drill hole on the top of a 1 m x 1 m x 1
m (4 ft x 3 ft x 2 ft) high boulder at the base of a bluff on the beach north of
the Port MacKenzie dock, 73.15 m (240.0 ft) south of bench mark 5934 D 2001,
9.20 m (30.2 ft) SE of a 0.25m (0.8ft) cottonwood with a duplex nail driven in
the face 0.30 m (1.0 ft) above ground, and approximately at the high water line.
BENCH MARK STAMPING: 5934 F 2001
DESIGNATION: 945 5934 F
MONUMENTATION: Tidal Station disk VM#: 16616
AGENCY: Terra Surveys, LLC. PID:
SETTING CLASSIFICATION: Dock
The bench mark is a disk brazed to a 0.13 m x 0.13 m (0.4 ft x 0.4 ft) steel
plate that is welded to the top of the dock face on the south end of the Port
MacKenzie Dock, 28.59 m (93.8 ft) west of a scribed "X" in the dock wall, 15.45
m (50.7 ft) south of a scribed "X" on the dock face, 1.1 m (3.6 ft) NE of a
bollard, and 0.30 m (1.0 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9455934 PUBLICATION DATE: 05/23/2003
Name: PORT MACKENZIE, COOK INLET
ALASKA
NOAA Chart: 16665 Latitude: 61° 16.1' N
USGS Quad: ANCHORAGE (B-8) Longitude: 149° 55.0' W
T I D A L D A T U M S
Tidal datums at PORT MACKENZIE, COOK INLET based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: June 2001 - August 2001
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9455920 ANCHORAGE, KNIK ARM, COOK INLET
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER (MHHW) = 8.870
MEAN HIGH WATER (MHW) = 8.649
MEAN SEA LEVEL (MSL) = 4.952
MEAN TIDE LEVEL (MTL) = 4.664
MEAN LOW WATER (MLW) = 0.680
MEAN LOWER LOW WATER (MLLW) = 0.000
National Geodetic Vertical Datum (NGVD 29)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
5934 A 2001 7.994 -0.655
5934 B 2001 9.273 0.624
5934 C 2001 9.124 0.475
5934 D 2001 10.748 2.099
5934 E 2001 8.888 0.239
5934 F 2001 11.118 2.469
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9455934 PUBLICATION DATE: 05/23/2003
Name: PORT MACKENZIE, COOK INLET
ALASKA
NOAA Chart: 16665 Latitude: 61° 16.1' N
USGS Quad: ANCHORAGE (B-8) Longitude: 149° 55.0' W
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 (NAVD 88).
NGVD 29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD 29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD 88 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. NAVD 88 replaces NGVD 29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD 88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD 88 elevations.
The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD 88 elevations listed for
each bench mark in the NGS database.