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National Ocean Service
Datums Page Page 1 of 6
Station ID: 9457634 PUBLICATION DATE: 06/29/2018
Name: JAPANESE BAY, KODIAK ISLAND
AK
NOAA Chart: 16590 Latitude: 56° 57.6' N ( 56.96000)
USGS Quad: KAGUYAK (D-6) Longitude: 153° 41.2' W (-153.68700)
To reach the tidal bench marks from opening of Japanese Bay, Alaska, proceed
north into Japanese Bay by water craft for 4.07 km (2.2nm) continuing around the
east point of the peninsula located inside Japanese Bay, continue NW on Japanese
Bay for 0.81 km (0.44nm) to a prominent pebbled, sandy beach point on the west
side of inner portion of Japanese Bay, then disembark water craft and onto beach
marked by a sandy point. The bench marks are in the vicinity of the sand point.
The tide gauge was Located at Primary Benchmark D Lat: 56 57.592"N Lon: 153
41.454"W.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7634 D 2014
DESIGNATION: 945 7634 D
MONUMENTATION: Tidal Station disk VM#: 21258
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: In bedrock OPUS PID#: BBDQ89
LATITUDE: 56° 57.6' N ( 56.95983) LONGITUDE: 153° 41.4' W (-153.69083)
The primary benchmark is a disk set in a small rock outcrop located where the
slope increases at the foot of a grassy hill that merges with beach, 106.70 m
(350 ft) NW of the point on the west side of inner portion of Japanese Bay and
4.6 m (15 ft) above the mean high water.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9457634 PUBLICATION DATE: 06/29/2018
Name: JAPANESE BAY, KODIAK ISLAND
AK
NOAA Chart: 16590 Latitude: 56° 57.6' N ( 56.96000)
USGS Quad: KAGUYAK (D-6) Longitude: 153° 41.2' W (-153.68700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7634 E 2014
DESIGNATION: 945 7634 E
MONUMENTATION: Tidal Station disk VM#: 21257
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: In bedrock OPUS PID:
LATITUDE: 56° 57.6' N ( 56.95950) LONGITUDE: 153° 41.4' W (-153.69017)
The benchmark is a disk set in a medium flat boulder located 45.73 m (150 ft) NW
of the point on the west side of inner portion of Japanese Bay and 1.52 m (5 ft)
above the mean high water.
BENCH MARK STAMPING: 7634 F 2014
DESIGNATION: 945 7634 F
MONUMENTATION: Tidal Station disk VM#: 21261
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: In bedrock OPUS PID:
LATITUDE: 56° 57.7' N ( 56.96117) LONGITUDE: 153° 41.4' W (-153.69083)
The benchmark is a disk set in a small boulder located 149.39 m (490 ft) NW of
point on west side of inner portion of Japanese Bay and 2.44m (8ft) above the
mean high water.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9457634 PUBLICATION DATE: 06/29/2018
Name: JAPANESE BAY, KODIAK ISLAND
AK
NOAA Chart: 16590 Latitude: 56° 57.6' N ( 56.96000)
USGS Quad: KAGUYAK (D-6) Longitude: 153° 41.2' W (-153.68700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: S9447 C1 1987
DESIGNATION: S9447
MONUMENTATION: Bench Mark disk VM#: 21262
AGENCY: US Department of the Interior IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 56° 57.5' N ( 56.95817) LONGITUDE: 153° 41.5' W (-153.69150)
The benchmark is a disk set in an elevated flange encased rod sunk into the
tundra at top of bluff 33.48 m (100 ft) SW of four large hemlock trees. Note:
When recovered the rod was unstable.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9457634 PUBLICATION DATE: 06/29/2018
Name: JAPANESE BAY, KODIAK ISLAND
AK
NOAA Chart: 16590 Latitude: 56° 57.6' N ( 56.96000)
USGS Quad: KAGUYAK (D-6) Longitude: 153° 41.2' W (-153.68700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: JAP BAY 3 1931
DESIGNATION: JAP BAY 3 1931
MONUMENTATION: Bench Mark disk VM#: 21263
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: In bedrock OPUS PID:
LATITUDE: 56° 57.5' N ( 56.95850) LONGITUDE: 153° 41.5' W (-153.69117)
The benchmark is a disk set in a large boulder located 121.92 m (400 ft) SW of
point on west side of inner portion of Japanese Bay and 2.43 m (8 ft) away from
high water line. Note: This disk is now green in color because of oxidization.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9457634 PUBLICATION DATE: 06/29/2018
Name: JAPANESE BAY, KODIAK ISLAND
AK
NOAA Chart: 16590 Latitude: 56° 57.6' N ( 56.96000)
USGS Quad: KAGUYAK (D-6) Longitude: 153° 41.2' W (-153.68700)
T I D A L D A T U M S
Tidal datums at JAPANESE BAY, KODIAK ISLAND based on:
LENGTH OF SERIES: 2 MONTHS
TIME PERIOD: June 2014 - July 2014
TIDAL EPOCH: 2012-2016
CONTROL TIDE STATION: 9457292 KODIAK ISLAND, WOMENS BAY
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.511
MEAN HIGH WATER MHW = 2.325
MEAN TIDE LEVEL MTL = 1.340
MEAN SEA LEVEL MSL = 1.335
MEAN LOW WATER MLW = 0.354
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7634 D 2014 3.107 0.782
7634 E 2014 2.367 0.042
7634 F 2014 2.384 0.059
S9447 C1 1987 9.384 7.059
JAP BAY 3 1931 3.530 1.205
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9457634 PUBLICATION DATE: 06/29/2018
Name: JAPANESE BAY, KODIAK ISLAND
AK
NOAA Chart: 16590 Latitude: 56° 57.6' N ( 56.96000)
USGS Quad: KAGUYAK (D-6) Longitude: 153° 41.2' W (-153.68700)
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.