U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 4
Station ID: 9455517 PUBLICATION DATE: 04/09/2018
Name: KASITSNA BAY, KACHEMAK BAY
AK
NOAA Chart: 16647 Latitude: 59° 28.1' N ( 59.46831)
USGS Quad: SELDOVIA (B-5) Longitude: 151° 33.9' W (-151.56500)
To reach the tidal bench marks which are located along the SW shore of Kasitsna
Bay on the point between the NOAA-UAF Kasitsna Bay Laboratory and Jakolof Bay,
you must travel either from the road above the beach or by small boat on the
beach itself. All recovered bench marks are in the immediate vicinity of an
abandoned chromium mine which operated briefly as a strategic chromium source
during WW2. Recovered bench marks 2 and 3 are on the beach and 3 and 4 are
located up the hill.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: No Stamping (TIDAL 6)
DESIGNATION: 945 5517 TIDAL 6
ALIAS:
MONUMENTATION: Tidal Station disk VM#: 18881
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete support footing OPUS PID#: BBFH92
LATITUDE: 59° 28.1' N ( 59.46792) LONGITUDE: 151° 33.1' W (-151.55197)
The primary bench mark is a disk set flush in the top of the concrete support
footing at the SW corner of the landward extension of the NOAA-UAF Kasitsna Bay
Laboratory pier, and approximately 5.50 m (18 ft) south of the NW corner of the
house at the entrance to the pier.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 4
Station ID: 9455517 PUBLICATION DATE: 04/09/2018
Name: KASITSNA BAY, KACHEMAK BAY
AK
NOAA Chart: 16647 Latitude: 59° 28.1' N ( 59.46831)
USGS Quad: SELDOVIA (B-5) Longitude: 151° 33.9' W (-151.56500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: BM 4 1973
DESIGNATION: 945 5517 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 18879
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Rock face OPUS PID:
LATITUDE: 59° 28.2' N ( 59.47031) LONGITUDE: 151° 32.8' W (-151.54664)
The bench mark is a disk set vertically in a rock face at the fork in the dirt
roads, just north of road running from Seldovia to Jakolof Bay and just west of
the old dirt road leading up to the chrome mine, and faces in an easterly
direction.
BENCH MARK STAMPING: BM 5 1973
DESIGNATION: 945 5517 TIDAL 5
MONUMENTATION: Tidal Station disk VM#: 18880
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Bedrock OPUS PID:
LATITUDE: 59° 28.2' N ( 59.47064) LONGITUDE: 151° 32.9' W (-151.54764)
The bench mark is a disk set horizontally in the bedrock forming the southerly
embankment for the (inclosing) old chrome mine chute which is above the mine
entrance, and the highest part of the embankment.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 4
Station ID: 9455517 PUBLICATION DATE: 04/09/2018
Name: KASITSNA BAY, KACHEMAK BAY
AK
NOAA Chart: 16647 Latitude: 59° 28.1' N ( 59.46831)
USGS Quad: SELDOVIA (B-5) Longitude: 151° 33.9' W (-151.56500)
T I D A L D A T U M S
Tidal datums at KASITSNA BAY, KACHEMAK BAY based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: August 2008 - August 2008
TIDAL EPOCH: 2012-2016
CONTROL TIDE STATION: 9455500 SELDOVIA, COOK INLET
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 5.531
MEAN HIGH WATER MHW = 5.285
MEAN SEA LEVEL MSL = 2.933
MEAN TIDE LEVEL MTL = 2.900
MEAN LOW WATER MLW = 0.514
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
No Stamping (TIDAL 6) 8.846 3.561
BM 4 1973 22.855 17.570
BM 5 1973 25.754 20.469
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 4
Station ID: 9455517 PUBLICATION DATE: 04/09/2018
Name: KASITSNA BAY, KACHEMAK BAY
AK
NOAA Chart: 16647 Latitude: 59° 28.1' N ( 59.46831)
USGS Quad: SELDOVIA (B-5) Longitude: 151° 33.9' W (-151.56500)
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.