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National Ocean Service
Datums Page Page 1 of 5
Station ID: 9451124 PUBLICATION DATE: 08/03/2004
Name: STIKINE STRAIT
AK
NOAA Chart: 17382 Latitude: 56° 21.2' N ( 56.35330)
USGS Quad: PETERSBURG (B-2) Longitude: 132° 33.2' W (-132.55300)
To reach the tidal bench marks from Wrangell, transit SSW through Zimovia
Strait, when abeam of Hat Island, proceed west through Chichagof Pass. The
tidal bench marks and tide station were located on the west side of Drag Island.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 1124 B 2000
DESIGNATION: 945 1124 B
MONUMENTATION: Tidal Station disk VM#: 16158
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 56° 21.2' N ( 56.35330) LONGITUDE: 132° 33.2' W (-132.55300)
The primary bench mark is a disk set at the base of a rocky outcrop that extends
from the tree line, located on the NW edge of the cobble beach on the west side
of Drag Island.
BENCH MARK STAMPING: 1124 A 2000
DESIGNATION: 945 1124 A
MONUMENTATION: Tidal Station disk VM#: 16157
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock outcrop OPUS PID:
LATITUDE: 56° 21.2' N ( 56.35330) LONGITUDE: 132° 33.2' W (-132.55300)
The bench mark is a disk set on top of a 7 m (23 ft) high rock outcrop on the
south edge of the cobble beach located on the west side of Drag Island, and 6.0
m (19.7 ft) from the vegetation line.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9451124 PUBLICATION DATE: 08/03/2004
Name: STIKINE STRAIT
AK
NOAA Chart: 17382 Latitude: 56° 21.2' N ( 56.35330)
USGS Quad: PETERSBURG (B-2) Longitude: 132° 33.2' W (-132.55300)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1124 C 2000
DESIGNATION: 945 1124 C
MONUMENTATION: Tidal Station disk VM#: 16159
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock outcrop OPUS PID:
LATITUDE: 56° 21.2' N ( 56.35330) LONGITUDE: 132° 33.2' W (-132.55300)
The bench mark is a disk set in a large bedrock outcrop located NW of the cobble
beach on the west side of Drag Island, and 5.30 m (17.4 ft) NW of a high
prominent rock ledge.
BENCH MARK STAMPING: 1124 D 2000
DESIGNATION: 945 1124 D
MONUMENTATION: Tidal Station disk VM#: 16160
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock outcrop OPUS PID:
LATITUDE: 56° 21.2' N ( 56.35330) LONGITUDE: 132° 33.2' W (-132.55300)
The bench mark is a disk set in a small bedrock outcrop which is located between
two larger rock outcrops that extend from the vegetation line, located on the
north side of Drag Island.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9451124 PUBLICATION DATE: 08/03/2004
Name: STIKINE STRAIT
AK
NOAA Chart: 17382 Latitude: 56° 21.2' N ( 56.35330)
USGS Quad: PETERSBURG (B-2) Longitude: 132° 33.2' W (-132.55300)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 1124 E 2000
DESIGNATION: 945 1124 E
MONUMENTATION: Tidal Station disk VM#: 16161
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Granite boulder OPUS PID:
LATITUDE: 56° 21.2' N ( 56.35330) LONGITUDE: 132° 33.2' W (-132.55300)
The bench mark is a disk set in a 1 m wide x 1 m high (4 ft x 2 ft) triangular
granite boulder which stands alone on a beach face dominated by cleaved slate on
the north side of Drag Island.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9451124 PUBLICATION DATE: 08/03/2004
Name: STIKINE STRAIT
AK
NOAA Chart: 17382 Latitude: 56° 21.2' N ( 56.35330)
USGS Quad: PETERSBURG (B-2) Longitude: 132° 33.2' W (-132.55300)
T I D A L D A T U M S
Tidal datums at STIKINE STRAIT based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: March 2000 - April 2000
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9450460 KETCHIKAN, TONGASS NARROWS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 4.863
MEAN HIGH WATER MHW = 4.592
MEAN TIDE LEVEL MTL = 2.525
MEAN SEA LEVEL MSL = 2.511
MEAN LOW WATER MLW = 0.457
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
1124 B 2000 6.242 1.650
1124 A 2000 5.965 1.372
1124 C 2000 5.702 1.109
1124 D 2000 6.303 1.711
1124 E 2000 4.553 -0.040
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9451124 PUBLICATION DATE: 08/03/2004
Name: STIKINE STRAIT
AK
NOAA Chart: 17382 Latitude: 56° 21.2' N ( 56.35330)
USGS Quad: PETERSBURG (B-2) Longitude: 132° 33.2' W (-132.55300)
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.