U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9447883 PUBLICATION DATE: 06/15/2016
Name: GREENBANK, PUGET SOUND
WA
NOAA Chart: 18423 Latitude: 48° 6.3' N ( 48.10500)
USGS Quad: FREELAND Longitude: 122° 34.2' W (-122.57000)
To reach the station from the Washington State Ferry terminal in Clinton on
Whidbey Island, proceed 27.0 km (16.8 mi) west and then north on WA 525 to the
intersection with North Bluff Road, turn right on North Bluff Road and proceed
north 0.5 km (0.3 mi) to the intersection with Wonn Road, turn right on Wonn
Road and proceed east 0.1 km (0.07 mi) to the end of the road and the private
beach and wooden offshore pilings straight ahead. The tide gauge is on the
beach and the bench marks are along Wonn Road and WA 525.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7883 A 2015
DESIGNATION: 944 7883 A
MONUMENTATION: Metal Rod VM#: 21739
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Deep Rod Mark OPUS PID:
LATITUDE: 48° 6.3' N ( 48.10511) LONGITUDE: 122° 34.4' W (-122.57267)
The mark is a flange encased rod set in the lawn N of a shed and S of Wonn Road,
56.35 m (184.9 ft) SE of the centerline of North Bluff Road, 13.48 m (44.2 ft) N
of the NW corner of the yellow house at 2909 North Bluff Road, 7.15 m (23.5 ft)
NNE of the NE corner of a shed, 6.37 m (20.9 ft) ENE of the NW corner of the
shed, 0.90 m (3.0 ft) SW of the N edge of the grass and beginning of the bramble
bordering Wonn Road. The datum point is set 2 cm (1 inch) below grade being the
top of a stainless steel rod driven 1.2 m (4 ft). to abrupt refusal in glacial
till, in a sleeve extending to a depth of 0.9 m (3.0 ft), and encased in a 6
inch NOS logo cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9447883 PUBLICATION DATE: 06/15/2016
Name: GREENBANK, PUGET SOUND
WA
NOAA Chart: 18423 Latitude: 48° 6.3' N ( 48.10500)
USGS Quad: FREELAND Longitude: 122° 34.2' W (-122.57000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7883 B 2015
DESIGNATION: 944 7883 B
MONUMENTATION: Flange-encased Rod VM#: 21740
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: OPUS PID#: BBDX65
LATITUDE: 48° 6.3' N ( 48.10570) LONGITUDE: 122° 34.5' W (-122.57422)
The bench mark is a flange encased rod set in the lawn S of Greenbank Farm and N
of Wonn Road, 22.51 m (73.9 ft) SE of second light pole N of Wonn Road along E
side of farm driveway, 19.63 m (64.4 ft) E of a stop sign on W side of farm
driveway, 19.02 m (62.4 ft) WNW of a fiber optic pedestal along north side of
Wonn Road, 13.75 m (45.1 ft) N of the centerline of Wonn Road, 6.57 m (21.6 ft)
ENE of a light pole and 5.28 m (17.3 ft) NE of N post for white Greenbank Farm
sign. The datum point is set 6 cm (2 inches) below grade, being the top of a
stainless steel rod driven 2.0 m (6.6 ft) to abrupt refusal, in a sleeve
extending to a depth of 0.9 m (3.0 ft), and encased in a 6-inch (15 cm) NOS logo
cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9447883 PUBLICATION DATE: 06/15/2016
Name: GREENBANK, PUGET SOUND
WA
NOAA Chart: 18423 Latitude: 48° 6.3' N ( 48.10500)
USGS Quad: FREELAND Longitude: 122° 34.2' W (-122.57000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: GP 15525-28 1997
DESIGNATION: GP15525 28
MONUMENTATION: Survey disk VM#: 21741
AGENCY: Washington State Department of
Transportation IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 48° 6.1' N ( 48.10242) LONGITUDE: 122° 34.5' W (-122.57519)
The mark is a disk in a concrete monument set in the grass along the E side of
WA 525, 31.86 m (104.5 ft) NNW of a stop sign at North Bluff Road and WA 525,
28.95 m (95.0 ft) W of a wood power pole on the W side of North Bluff Road,
15.49 m (50.8 ft) NW of the W post of the white Greenbank Farm sign, 3.09 m
(10.1 ft) SW of an evergreen tree, and 0.98 m (3.2 ft) SW of a carsonite witness
post.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9447883 PUBLICATION DATE: 06/15/2016
Name: GREENBANK, PUGET SOUND
WA
NOAA Chart: 18423 Latitude: 48° 6.3' N ( 48.10500)
USGS Quad: FREELAND Longitude: 122° 34.2' W (-122.57000)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7883 C 2015
DESIGNATION: 944 7883 C
MONUMENTATION: Flange-encased Rod VM#: 21742
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 48° 6.4' N ( 48.10589) LONGITUDE: 122° 34.7' W (-122.57767)
The mark is a flange encased rod set in the grass field on the N side of Wonn
Road, 42.12 m (138.2 ft) NNE of the stop sign at the intersection of Wonn Road
and WA 525, 42.01 m (137.8 ft) NNW of the centerline of Wonn Road at the
driveway entrance to this field, 27.08 m (88.8 ft) N of the taller of two fiber
optic pedestals, 22.95 m (75.3 ft) NE of the NE corner post of the Greenbank
farm sign, and 12.34 m (40.5 ft) S of the fence along the S side of a horse
pasture. The datum point is set 5 cm (2 inches) below grade being the top of a
stainless steel rod driven 1.2 m (4 ft) to abrupt refusal in glacial till, in a
sleeve extending to a depth of 0.9 m (3.0 ft), and encased in a 6 inch NOS logo
cover.
BENCH MARK STAMPING: 944 7883 TIDAL 3
DESIGNATION: 944 7883 TIDAL 3
MONUMENTATION: Bolt VM#: 21744
AGENCY: IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 48° 6.3' N ( 48.10475) LONGITUDE: 122° 34.3' W (-122.57197)
The mark is a steel bolt in a concrete monument on the N side of the opening in
a stone wall for the path leading to the beach, 18.20 m (59.7 ft) NE of the post
at the NW corner of the garage for 794 Wonn Road, 11.83 m (38.8 ft) ENE of the
center of the top of a large boulder W of the driveway for 794 Wonn Road, 1.90 m
(6.2 ft) N of south stone wall, and 0.50 m (1.6 ft) S of north stone wall.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9447883 PUBLICATION DATE: 06/15/2016
Name: GREENBANK, PUGET SOUND
WA
NOAA Chart: 18423 Latitude: 48° 6.3' N ( 48.10500)
USGS Quad: FREELAND Longitude: 122° 34.2' W (-122.57000)
T I D A L D A T U M S
Tidal datums at GREENBANK, PUGET SOUND based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: August 2015 - October 2015
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9447130 SEATTLE, PUGET SOUND
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 3.461
MEAN HIGH WATER MHW = 3.196
MEAN TIDE LEVEL MTL = 2.022
MEAN SEA LEVEL MSL = 2.016
MEAN LOW WATER MLW = 0.848
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7883 A 2015 6.239 3.043
7883 B 2015 10.959 7.763
GP 15525-28 1997 37.676 34.480
7883 C 2015 14.437 11.241
944 7883 TIDAL 3 4.366 1.170
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9447883 PUBLICATION DATE: 06/15/2016
Name: GREENBANK, PUGET SOUND
WA
NOAA Chart: 18423 Latitude: 48° 6.3' N ( 48.10500)
USGS Quad: FREELAND Longitude: 122° 34.2' W (-122.57000)
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.