U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 7
Station ID: 9450314 PUBLICATION DATE: 04/28/2010
Name: METLAKATLA, PORT CHESTER
AK
NOAA Chart: 17435 Latitude: 55° 7.7' N ( 55.12830)
USGS Quad: KETCHIKAN (A-5) Longitude: 131° 34.0' W (-131.56700)
To reach the tide station from the new Metlakatla sea plane floating dock, turn
left out of the parking lot and travel SE on Lower Atkinson Street 0.24 km (0.24
mi) to where the road bends to the left and turns into Tait St, follow Tait
Street east then SE for 0.50 km (0.31 mi) and take a hard (170 ) left turn onto
Dale Horne Road, travel NNW 102 m (336 ft) to the top of the boat launch, stay
on the gravel road to the right of the boat launch traveling NNE for 130 m (430
ft) to the base of the Metlakatla City Dock. The tide house was on the dock next
to the sheet metal storage building and orifices were below it attached to the
pilings of the dock. The primary bench mark is near the base of the dock and
other bench marks are along the road to the cannery.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: BM 11 1969
DESIGNATION: 945 0314 NO 11
MONUMENTATION: Survey disk VM#: 14121
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete pad OPUS PID#: BBFF94
LATITUDE: 55° 7.7' N ( 55.12768) LONGITUDE: 131° 34.1' W (-131.56911)
The primary bench mark is set in the concrete pad of a green transformer box
near the base of the breakwater for the Old Harbor on the eastern corner of the
pad, 16.76 m (54.9 ft) west of a red fire hydrant at the base of the city dock,
2.27 m (7.4 ft) NW of the guardrail on the western side of the paved road to the
city dock, 0.18 m (0.6 ft) SW of the NE edge of the concrete pad and 0.17 m (0.6
ft) NE of the SW edge of the concrete pad.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 7
Station ID: 9450314 PUBLICATION DATE: 04/28/2010
Name: METLAKATLA, PORT CHESTER
AK
NOAA Chart: 17435 Latitude: 55° 7.7' N ( 55.12830)
USGS Quad: KETCHIKAN (A-5) Longitude: 131° 34.0' W (-131.56700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 13 1969
DESIGNATION: 945 0314 NO 13
MONUMENTATION: Survey disk VM#: 14123
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: AB7164
SETTING CLASSIFICATION: Rock OPUS PID:
LATITUDE: 55° 7.6' N ( 55.12697) LONGITUDE: 131° 34.2' W (-131.57028)
The bench mark is set in the top of a 1.2 m x 1.75 m x 1.5 m (3.9 ft x 5.7 ft x
4.9 ft) rock that s part of the shore side riprap barrier of the Old Harbor
along the road to the cannery between the boat launch and the wooden pier to the
Old Harbor dock, 38.25 m (125.5 ft) SSE of the base of the wooden pier, 27.90 m
(91.5 ft) NW of the centerline of the top of the boat launch ramp and 5.55 m
(18.2 ft) east of the centerline of Cannery Road.
BENCH MARK STAMPING: BM 14 1969
DESIGNATION: 945 0314 NO 14
MONUMENTATION: Survey disk VM#: 19552
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete pad OPUS PID:
LATITUDE: 55° 7.7' N ( 55.12885) LONGITUDE: 131° 34.3' W (-131.57182)
The bench mark is set in the concrete pad of a green transformer box near the
southern most loading dock overhead doors of the cannery, 35.59 m (116.8 ft)
north of the center of the gate across Cannery Road at the southern entrance to
the cannery, 5.63 m (18.5 ft) SSW of the southern corner of the building at the
loading dock, 0.17 m (0.6 ft) NE of SW edge of concrete pad and 0.16 m (0.5 ft)
SE of NW edge of concrete pad.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 7
Station ID: 9450314 PUBLICATION DATE: 04/28/2010
Name: METLAKATLA, PORT CHESTER
AK
NOAA Chart: 17435 Latitude: 55° 7.7' N ( 55.12830)
USGS Quad: KETCHIKAN (A-5) Longitude: 131° 34.0' W (-131.56700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0314 A 2009
DESIGNATION: 945 0314 A
MONUMENTATION: Tidal Station disk VM#: 19553
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete abutment OPUS PID#: BBBQ42
LATITUDE: 55° 7.7' N ( 55.12750) LONGITUDE: 131° 34.1' W (-131.56874)
The bench mark is set in the southern side of the concrete abutment of the barge
loading ramp near the city dock, 21.90 m (71.8 ft) east of the centerline of the
paved road to the city dock, 3.25 m (10.7 ft) SE of the center of the top of the
barge loading ramp, 0.42 m (1.4 ft) SW of the NE edge of the concrete abutment
and 0.31 m (1.0 ft) NW of the SE edge of the concrete abutment.
BENCH MARK STAMPING: 0314 B 2009
DESIGNATION: 945 0314 B
MONUMENTATION: Tidal Station disk VM#: 19554
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Riprap barrier OPUS PID:
LATITUDE: 55° 7.6' N ( 55.12738) LONGITUDE: 131° 34.3' W (-131.57099)
The bench mark is set in the top of a 2.4 m x 1.6 m x 0.6 m (7.9 ft x 5.2 ft x
2.0 ft) rock that s part of the shore side riprap barrier of the Old Harbor
along the road to the cannery, 33.37 m (109.5 ft) NNE of the center of the base
of the wooden pier to the Old Harbor dock, 13.68 m (44.9 ft) ENE of the edge of
a rock filled chain-link retaining wall and 7.29 m (23.9 ft) ENE of the
centerline of Cannery Road.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 7
Station ID: 9450314 PUBLICATION DATE: 04/28/2010
Name: METLAKATLA, PORT CHESTER
AK
NOAA Chart: 17435 Latitude: 55° 7.7' N ( 55.12830)
USGS Quad: KETCHIKAN (A-5) Longitude: 131° 34.0' W (-131.56700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0314 C 2009
DESIGNATION: 945 0314 C
MONUMENTATION: Tidal Station disk VM#: 19555
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Riprap barrier OPUS PID:
LATITUDE: 55° 7.7' N ( 55.12792) LONGITUDE: 131° 34.3' W (-131.57125)
The bench mark is set in the top of a 1.0 m x 1.1 m x 0.7 m (3.3 ft x 3.6 ft x
2.3 ft) rock that s part of the shore side riprap barrier of the Old Harbor
along the road to the cannery, 82.25 m (269.8 ft) SSE of the center of the gate
across Cannery Road at the southern entrance to the cannery, 9.93 m (32.6 ft)
ENE of the edge of a rock filled chain-link retaining wall and 5.45 m (17.9 ft)
ENE of the centerline of Cannery Road.
BENCH MARK STAMPING: 0314 D 2009
DESIGNATION: 945 0314 D
MONUMENTATION: Tidal Station disk VM#: 19556
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: in concrete OPUS PID:
LATITUDE: 55° 7.7' N ( 55.12914) LONGITUDE: 131° 34.4' W (-131.57304)
The bench mark is set in the concrete pad of the southern most of two green
transformer boxes found at the western entrance to the cannery, 8.76 m (28.7 ft)
NNW of the NW corner of the cannery guard shack at the west entrance to the
cannery, 3.65 m (12.0 ft) ENE of the centerline of the narrow paved road to the
western entrance, 0.21 m (0.7 ft) SSW of the NNE edge of concrete pad and 0.17 m
(0.6 ft) ESE of the WNW edge of concrete pad.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 7
Station ID: 9450314 PUBLICATION DATE: 04/28/2010
Name: METLAKATLA, PORT CHESTER
AK
NOAA Chart: 17435 Latitude: 55° 7.7' N ( 55.12830)
USGS Quad: KETCHIKAN (A-5) Longitude: 131° 34.0' W (-131.56700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 0314 E 2009
DESIGNATION: 945 0314 E
MONUMENTATION: Tidal Station disk VM#: 19557
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete footings OPUS PID:
LATITUDE: 55° 7.7' N ( 55.12890) LONGITUDE: 131° 34.4' W (-131.57345)
The bench mark is set in the top of the southwestern most of six buried pyramid
shaped concrete footings with a flat 0.5 m x 0.5 m (1.6 ft x 1.6 ft) top and 1.2
m x 1.2 m (3.9 ft x 3.9 ft) wide base, 16.45 m (54.0 ft) NNE of the centerline
of Tait Street, 8.69 m (28.5 ft) west of the western most corner of the large
white house on Tait Street at the western entrance to the cannery that serves as
cannery housing, 0.12 m (0.4 ft) SSW of the NNE edge of concrete and 0.11 m (0.4
ft) WNW of the ESE edge of concrete.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 7
Station ID: 9450314 PUBLICATION DATE: 04/28/2010
Name: METLAKATLA, PORT CHESTER
AK
NOAA Chart: 17435 Latitude: 55° 7.7' N ( 55.12830)
USGS Quad: KETCHIKAN (A-5) Longitude: 131° 34.0' W (-131.56700)
T I D A L D A T U M S
Tidal datums at METLAKATLA, PORT CHESTER based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: November 2009 - December 2009
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 = 4.531
MEAN HIGH WATER MHW = 4.260
MEAN TIDE LEVEL MTL = 2.366
MEAN SEA LEVEL MSL = 2.363
MEAN LOW WATER MLW = 0.472
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
BM 11 1969 7.298 3.037
BM 13 1969 6.101 1.840
BM 14 1969 6.772 2.511
0314 A 2009 7.186 2.925
0314 B 2009 5.366 1.105
0314 C 2009 6.167 1.907
0314 D 2009 9.360 5.099
0314 E 2009 10.695 6.434
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 7
Station ID: 9450314 PUBLICATION DATE: 04/28/2010
Name: METLAKATLA, PORT CHESTER
AK
NOAA Chart: 17435 Latitude: 55° 7.7' N ( 55.12830)
USGS Quad: KETCHIKAN (A-5) Longitude: 131° 34.0' W (-131.56700)
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.