U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 9413651 PUBLICATION DATE: 05/01/2009
Name: KIRBY PARK, ELKHORN SLOUGH
CA
NOAA Chart: 18680 Latitude: 36° 50.5' N ( 36.84133)
USGS Quad: PRUNEDALE Longitude: 121° 44.7' W (-121.74528)
To reach the tidal bench marks from State Highway 1 to Moss Landing at the power
plant, turn east onto Dolan Road for 5.6 km (3.5 mi), make a left on Elkhorn
Road, proceed about 8 km (5 mi) to Kirby Park entrance on the left. The bench
marks are located on both sides of the railroad tracks (parallel to the slough).
The tide gage and staff were located on a freestanding piling on Elkhorn Slough
and in line with the fence post leading to the slough.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 3651 B 1977
DESIGNATION: 941 3651 B TIDAL
MONUMENTATION: Tidal Station disk VM#: 11895
AGENCY: National Ocean Survey (NOS) IDB PID#: GU3199
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 36° 50.5' N ( 36.84170) LONGITUDE: 121° 44.8' W (-121.74700)
The primary bench mark is located in Kirby Park along Elkhorn Slough, 12 m (40
ft) south of south rail of South Pacific Railroad tracks, and 7.30 m (24.0 ft)
north of the center of the trail. The bench mark is set 0.15 m (0.5 ft) below
the grade, crimped to a stainless steel rod driven to 12.19 m (40 ft), encased
in a PVC pipe and 0.21 m (0.7 ft) below top of pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 9413651 PUBLICATION DATE: 05/01/2009
Name: KIRBY PARK, ELKHORN SLOUGH
CA
NOAA Chart: 18680 Latitude: 36° 50.5' N ( 36.84133)
USGS Quad: PRUNEDALE Longitude: 121° 44.7' W (-121.74528)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3651 C 1977
DESIGNATION: 941 3651 C TIDAL
MONUMENTATION: Tidal Station disk VM#: 11896
AGENCY: National Ocean Survey (NOS) IDB PID#: GU3200
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 36° 50.5' N ( 36.84170) LONGITUDE: 121° 44.8' W (-121.74700)
The bench mark is located in Kirby Park along Elkhorn Slough, 22 m (71 ft) south
of south rail, 6.40 m (21.0 ft) south of center of trail, and 0.60 m (2 ft) east
of orange witness post. The bench mark is set 0.12 m (0.4 ft) below the grade,
crimped to a stainless steel rod driven to 12.19 m (40.0 ft) and encased in a
PVC pipe.
BENCH MARK STAMPING: 3651 J 2007
DESIGNATION: 941 3651 J
MONUMENTATION: Flange-encased Rod VM#: 18332
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 36° 50.4' N ( 36.84000) LONGITUDE: 121° 44.6' W (-121.74300)
The bench mark is located located in Kirby Park on Elkhorn Slough north of
parking lot, 16.15 m SW of 1/4 sign on south side of tracks, 13.72 m (45 ft)
south of southern most rail, 1.16m (3.8ft) NE of the 33rd fence post from the
east end of lot, and 0.12 m (0.4 ft) west of orange witness post. The datum
point is the top of a stainless steel rod driven 12.2 m (40 ft) and encased in a
5-inch NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 9413651 PUBLICATION DATE: 05/01/2009
Name: KIRBY PARK, ELKHORN SLOUGH
CA
NOAA Chart: 18680 Latitude: 36° 50.5' N ( 36.84133)
USGS Quad: PRUNEDALE Longitude: 121° 44.7' W (-121.74528)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 3651 H 2007
DESIGNATION: 941 3651 H
MONUMENTATION: Tidal Station disk VM#: 18333
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 36° 50.4' N ( 36.84000) LONGITUDE: 121° 44.6' W (-121.74300)
The bench mark is a disk set in the base for floating dock, located in Kirby
Park along Elkhorn Slough, 9.90 m (32.5 ft) east of middle of the most eastern
piling for dock, 4.70 m (15.4 ft) north of south side of a boat ramp, 0.51 m
(1.7 ft) south of north side of the dock, and 0.67 m (2.2 ft) above ground.
BENCH MARK STAMPING: 3631 E 2007
DESIGNATION: 941 3651 E
MONUMENTATION: Tidal Station disk VM#: 18483
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete filled pipe OPUS PID:
LATITUDE: 36° 50.4' N ( 36.84000) LONGITUDE: 121° 44.6' W (-121.74300)
The bench mark is set in a top western most concrete filled steel pipe for gate
entrance to trail located in Kirby Park along Elkhorn Slough, 22 m (73 ft) NW
of stop sign for railroad, 20.54 m (67.4 ft) south of southern most rail, and
1.14 m (3.8 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 9413651 PUBLICATION DATE: 05/01/2009
Name: KIRBY PARK, ELKHORN SLOUGH
CA
NOAA Chart: 18680 Latitude: 36° 50.5' N ( 36.84133)
USGS Quad: PRUNEDALE Longitude: 121° 44.7' W (-121.74528)
T I D A L D A T U M S
Tidal datums at KIRBY PARK, ELKHORN SLOUGH based on:
LENGTH OF SERIES: 4 MONTHS
TIME PERIOD: June 2008 - September 2008
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9413450 MONTEREY, MONTEREY HARBOR
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.680
MEAN HIGH WATER MHW = 1.462
MEAN SEA LEVEL MSL = 0.901
MEAN TIDE LEVEL MTL = 0.896
MEAN LOW WATER MLW = 0.330
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum NAVD88 = -0.041
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
3651 B 1977 2.080 0.618
3651 C 1977 2.159 0.697
3651 J 2007 2.350 0.888
3651 H 2007 2.011 0.549
3631 E 2007 3.458 1.996
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 9413651 PUBLICATION DATE: 05/01/2009
Name: KIRBY PARK, ELKHORN SLOUGH
CA
NOAA Chart: 18680 Latitude: 36° 50.5' N ( 36.84133)
USGS Quad: PRUNEDALE Longitude: 121° 44.7' W (-121.74528)
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.