U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
PUBLICATION DATE: 10/31/1984
Station ID: 9451600 SUPERCEDED DATE: 04/21/2003
Name: SITKA, BARANOF ISLAND, SITKA SOUND
ALASKA
NOAA Chart: 17327 Latitude: 57° 3.1' N
USGS Quad: SITKA A-4 Longitude: 135° 20.5' W
To reach the tidal bench marks from the Sitka Post Office at Lincoln and Katlian
Streets, proceed 0.25 mile (0.40 km) NW on Katlian Street to the Sitka Sound
Seafood Dock, and continue seaward down the pier 250 feet (76 m) to a small dry
goods storage shed on the east side of the pier with a tide station sign over
the sliding door. The bench marks are located in the general vicinity of Sitka
near Castle Hill. The tide station is a 5 foot (2 m) x 7 foot (2 m) x 9 foot (3
m) high area within the building.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1600 L 1982
MONUMENTATION: Survey Disk VM#: 1186
AGENCY: PID:
SETTING CLASSIFICATION: Rock Outcrop
The bench mark is set in the NE end of a bedrock outcrop on the north side of
the Alaska Pioneers Home grounds, 36 feet (11 m) south of a 8 foot (2 m) high
chain link fence, 22.2 feet (6.8 m) west of the NW corner of a yellow cement
building, and 1 foot (0.3 m) from the outcrop edge. The bench mark is 3.4 feet
(1.0 m) above ground level.
BENCH MARK STAMPING: TIDAL 26 1974
MONUMENTATION: Survey Disk VM#: 1178
AGENCY: PID#: UW8044
SETTING CLASSIFICATION: Rock Outcrop
The bench mark is set in the top of a 5-foot (2 m) high bedrock outcrop where
pavement ends 100 feet (30 m) south of the Russian blockhouse #1 south wall, 42
feet (13 m) NE of the NE corner of the 8-foot (2 m) high chain link fence around
the Sitka Pioneer Home, 18 feet (5 m) north of the centerline of Seward Street,
and 14.5 feet (4.4 m) SW of telephone pole #3485.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
PUBLICATION DATE: 10/31/1984
Station ID: 9451600 SUPERCEDED DATE: 04/21/2003
Name: SITKA, BARANOF ISLAND, SITKA SOUND
ALASKA
NOAA Chart: 17327 Latitude: 57° 3.1' N
USGS Quad: SITKA A-4 Longitude: 135° 20.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 16 1941
MONUMENTATION: Survey Disk VM#: 1179
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Sidewalk
The bench mark is set in the concrete sidewalk leading diagonally eastward to
the Pioneer Monument at the NW corner of the Alaska Pioneers Home Grounds, 17
feet (5 m) south of the Homes north boundary wall, 2.5 feet (0.8 m) from the
inner edge of the Katlian Street sidewalk, and 0.8 foot (0.2 m) north of a low
retaining wall.
BENCH MARK STAMPING: 1600 J 1977
MONUMENTATION: Survey Disk VM#: 1180
AGENCY: PID:
SETTING CLASSIFICATION: Rock Outcrop
The bench mark is set in a 4-foot (1.2 m) by 10 foot (3 m) rock outcrop in a
vacant lot north of camp #1, Alaska Legal Service building, 450 feet (137 m)
south along the Katlian Street centerline of Bench Mark Tidal 24 1974, 86 feet
(26 m) east of the Katlian Street centerline, and 29 feet (8.8 m) south of
telephone pole #6 (3491).
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
PUBLICATION DATE: 10/31/1984
Station ID: 9451600 SUPERCEDED DATE: 04/21/2003
Name: SITKA, BARANOF ISLAND, SITKA SOUND
ALASKA
NOAA Chart: 17327 Latitude: 57° 3.1' N
USGS Quad: SITKA A-4 Longitude: 135° 20.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8 1924
MONUMENTATION: Survey Disk VM#: 1181
AGENCY: PID:
SETTING CLASSIFICATION: Rock Outcrop
The bench mark is set in a 50 foot (15 m) diameter rock adjacent to the rock
fill south of the Japonski Island bridge and SW of the Sitka Post Office, 375
feet (114 m) east of the Standard Oil Company, 300 feet (91 m) SE of the south
corner of the Alaska Communications building, 63.5 feet (19.4 m) south of the SW
corner of an 8-foot (2 m) square grey wooden building, 30 feet (9 m) south of
the southern most corner of a concrete block supporting the southern most of 3
legs of a large radar dish which has Scientific Atlanta on it, SW of the Sitka
Post Office.
BENCH MARK STAMPING: 22 1965
MONUMENTATION: Survey Disk VM#: 1182
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Abutment
The bench mark is set in the east concrete abutment of the first set of steps
leading into the front entrance of the Post Office/Courthouse on Lincoln Street,
100 feet (30 m) SW of the intersection of Lincoln and Katlian Streets, 34 feet
(10 m) south of the centerline of Lincoln Street, 10.5 feet (3.2 m) east of the
abutment to the second set of steps, and 10 feet (3 m) south of the center of
the sidewalk. The bench mark is 3 feet (1 m) above the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
PUBLICATION DATE: 10/31/1984
Station ID: 9451600 SUPERCEDED DATE: 04/21/2003
Name: SITKA, BARANOF ISLAND, SITKA SOUND
ALASKA
NOAA Chart: 17327 Latitude: 57° 3.1' N
USGS Quad: SITKA A-4 Longitude: 135° 20.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: TIDAL 24 1974
MONUMENTATION: Survey Disk VM#: 1183
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Floor
The bench mark is set in the north end of a 10 foot (3 m) by 11 foot (3 m) high
garage door entrance of the Sitka Seafood and Sausage Factory (across the street
from the Sitka Sound dock), and 57 feet (17 m) east of the centerline of Katlian
Street.
BENCH MARK STAMPING: TIDAL 25 1974
MONUMENTATION: Survey Disk VM#: 1184
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Pillar
The bench mark is set vertically in the west face of the northeasternmost
concrete support pillar of the Japonski Island bridge, 150 feet (46 m) NE of
Bench Mark 8 1924, 115 feet (35 m) west of the western edge of the stairs
leading down from the bridge, 30.5 feet (9.3 m) south of the south edge of the
road extended beneath the bridge, and 1 foot (0.3 m) north of the southern edge
of the pillar. The bench mark is 2 feet (1 m) above ground level.
BENCH MARK STAMPING: TIDAL BM 1600 K 1978
MONUMENTATION: Survey Disk VM#: 1185
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Abutment
The bench mark is set vertically in the west face of the NW bridge abutment on
the east side of Japonski Island bridge, 124 feet (38 m) west of Bench Mark
Tidal 25 1974, 65 feet (20 m) south of the bridge road centerline extended to
beneath the bridge, and 23 feet (7 m) NNW of a 8 foot (2 m) by 8 foot (2 m) gray
utility building. The bench mark is 2.3 feet (0.7 m) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
PUBLICATION DATE: 10/31/1984
Station ID: 9451600 SUPERCEDED DATE: 04/21/2003
Name: SITKA, BARANOF ISLAND, SITKA SOUND
ALASKA
NOAA Chart: 17327 Latitude: 57° 3.1' N
USGS Quad: SITKA A-4 Longitude: 135° 20.5' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO STAMPING 1
MONUMENTATION: Survey Disk VM#: 1187
AGENCY: PID:
SETTING CLASSIFICATION: Concrete Base
The bench mark is set in the SE corner of the base of a three anchor monument at
the downtown Sitka Waterfront Park area, 157 feet (48 m) NW of Bench Mark 22
1965, 125 feet (38 m) NW of the centerline of Lincoln Street, 94 feet (29 m) SW
of the centerline of Katlian Avenue, 75 feet (23 m) NE of the seawall, and 7
feet (2 m) NE of the George Benson Totem Pole.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
PUBLICATION DATE: 10/31/1984
Station ID: 9451600 SUPERCEDED DATE: 04/21/2003
Name: SITKA, BARANOF ISLAND, SITKA SOUND
ALASKA
NOAA Chart: 17327 Latitude: 57° 3.1' N
USGS Quad: SITKA A-4 Longitude: 135° 20.5' W
T I D A L D A T U M S
Tidal datums at SITKA, BARANOF ISLAND, SITKA SOUND based on:
LENGTH OF SERIES: 19 YEARS
TIME PERIOD: 1960-1978
TIDAL EPOCH: 1960-1978
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:
HIGHEST OBSERVED WATER LEVEL (11/02/1948) = 14.68
MEAN HIGHER HIGH WATER MHHW = 9.91
MEAN HIGH WATER MHW = 9.14
MEAN TIDE LEVEL MTL = 5.29
MEAN LOW WATER MLW = 1.45
MEAN LOWER LOW WATER MLLW = 0.00
LOWEST OBSERVED WATER LEVEL (07/21/1978) = -3.82
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In FEET above:
Stamping or Designation MLLW MHW
1600 L 1982 40.12 30.98
TIDAL 26 1974 40.95 31.81
16 1941 20.36 11.22
1600 J 1977 29.36 20.22
8 1924 13.40 4.26
22 1965 23.27 14.13
TIDAL 24 1974 19.88 10.74
TIDAL 25 1974 19.06 9.92
TIDAL BM 1600 K 1978 20.76 11.62
NO STAMPING 1 19.45 10.31
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
PUBLICATION DATE: 10/31/1984
Station ID: 9451600 SUPERCEDED DATE: 04/21/2003
Name: SITKA, BARANOF ISLAND, SITKA SOUND
ALASKA
NOAA Chart: 17327 Latitude: 57° 3.1' N
USGS Quad: SITKA A-4 Longitude: 135° 20.5' 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 (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 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.