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National Ocean Service
Datums Page Page 1 of 6
Station ID: 9447814 PUBLICATION DATE: 07/15/2004
Name: GLENDALE, POSSESSION SOUND
WA
NOAA Chart: 18443 Latitude: 47° 56.4' N ( 47.94000)
USGS Quad: MUKILTEO Longitude: 122° 21.4' W (-122.35700)
To reach the tidal bench marks from Mukilteo, proceed by ferry across the
Possession Sound to the ferry landing at Columbia Beach, Whidbey Island, then
proceed south by car on Humphrey Road for approximately 3.7 km (2.3 mi) to the
town of Glendale. The bench marks are located in the vicinity of the pier and
along the road leading to the pier. The tide gage and staff were located on the
pier.
T I D A L B E N C H M A R K S
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9447814 PUBLICATION DATE: 07/15/2004
Name: GLENDALE, POSSESSION SOUND
WA
NOAA Chart: 18443 Latitude: 47° 56.4' N ( 47.94000)
USGS Quad: MUKILTEO Longitude: 122° 21.4' W (-122.35700)
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: MARSH 2 2 1924
DESIGNATION: MARSH 2 RM 2
ALIAS: 5
MONUMENTATION: Reference Mark disk VM#: 9213
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#: SY0225
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 47° 56.3' N ( 47.93830) LONGITUDE: 122° 21.5' W (-122.35800)
The primary bench mark is a disk set in the top of a 0.24 m (0.8 ft) square
concrete monument, 37 m (123 ft) NE of the old two-story building, 30 m (99 ft)
north of the centerline of the road leading east and downhill to the beach, 13 m
(42 ft) east of the centerline of the road parallel to the beach, 10 m (33 ft)
west of the sea wall, 1.37 m (4.5 ft) NE of the NE corner of the south one of
three cottages facing the beach, and level with the ground. NOTE: Mark not
found in 1980 by local engineer.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9447814 PUBLICATION DATE: 07/15/2004
Name: GLENDALE, POSSESSION SOUND
WA
NOAA Chart: 18443 Latitude: 47° 56.4' N ( 47.94000)
USGS Quad: MUKILTEO Longitude: 122° 21.4' W (-122.35700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: MARSH 2 1 1924
DESIGNATION: MARSH 2 RM 1
ALIAS: 4
MONUMENTATION: Reference Mark disk VM#: 9212
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#: SY0227
SETTING CLASSIFICATION: Concrete porch OPUS PID:
LATITUDE: 47° 56.3' N ( 47.93830) LONGITUDE: 122° 21.5' W (-122.35800)
The bench mark is a disk set in the north corner of a concrete porch (walkway)
in front of an old two-story building approximately 28 m (93 ft) west of the sea
wall, 6 m (21 ft) south of the centerline of the road leading east and downhill
to the beach, 2.29 m (7.5 ft) west of the east side of the walkway, 0.21 m (0.7
ft) south of the north edge of the walkway, and 0.15 m (0.5 ft) above the ground
level.
BENCH MARK STAMPING: NO 2 1952
DESIGNATION: 944 7814 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 9214
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete manhole OPUS PID:
LATITUDE: 47° 56.4' N ( 47.94000) LONGITUDE: 122° 21.4' W (-122.35700)
The bench mark is a disk set flush in the south rim of a concrete manhole, 73 m
(240 ft) west of the centerline of the road along the beach, 64 m (210 ft) WNW
of the NE corner of a two-story building, 6 m (21 ft) SE of the SE corner of a
two-story building, 5 m (18 ft) north of the centerline of the road leading east
and downhill to the beach, and 6 cm (0.2 ft) above the ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9447814 PUBLICATION DATE: 07/15/2004
Name: GLENDALE, POSSESSION SOUND
WA
NOAA Chart: 18443 Latitude: 47° 56.4' N ( 47.94000)
USGS Quad: MUKILTEO Longitude: 122° 21.4' W (-122.35700)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1952
DESIGNATION: 944 7814 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 9215
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Retaining wall OPUS PID:
LATITUDE: 47° 56.4' N ( 47.94000) LONGITUDE: 122° 21.4' W (-122.35700)
The bench mark is a disk set in the top of a retaining wall that supports a
driveway leading into a garage, about 87 m (285 ft) WNW of the NE corner of a
two-story building, 20 m (66 ft) north of the centerline of the road leading
east and downhill to the beach, 5 m (15 ft) SW of the NW corner of a two-story
garage, and 2 m (8 ft) west of the west wall of the garage.
BENCH MARK STAMPING: NO 7 1966
DESIGNATION: 944 7814 TIDAL 7
MONUMENTATION: Tidal Station disk VM#: 9216
AGENCY: US Coast & Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete slab OPUS PID:
LATITUDE: 47° 56.4' N ( 47.94000) LONGITUDE: 122° 21.4' W (-122.35700)
The bench mark is a disk set flush in the SW corner of a 12 m x 15 m (40 ft x 50
ft) concrete slab used as a boat ramp, 21 m (70 ft) east of the NE corner of a
small white house, 19 m (61 ft) SE of the SE corner of a two-story building, and
10 m (34 ft) west of a wooden bulkhead.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9447814 PUBLICATION DATE: 07/15/2004
Name: GLENDALE, POSSESSION SOUND
WA
NOAA Chart: 18443 Latitude: 47° 56.4' N ( 47.94000)
USGS Quad: MUKILTEO Longitude: 122° 21.4' W (-122.35700)
T I D A L D A T U M S
Tidal datums at GLENDALE, POSSESSION SOUND based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: February 1977 - February 1977
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 = 3.364
MEAN HIGH WATER MHW = 3.108
MEAN TIDE LEVEL MTL = 1.984
MEAN SEA LEVEL MSL = 1.976
MEAN LOW WATER MLW = 0.860
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
MARSH 2 2 1924 4.253 1.145
MARSH 2 1 1924 4.457 1.349
NO 2 1952 6.761 3.653
NO 3 1952 10.792 7.684
NO 7 1966 4.258 1.150
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9447814 PUBLICATION DATE: 07/15/2004
Name: GLENDALE, POSSESSION SOUND
WA
NOAA Chart: 18443 Latitude: 47° 56.4' N ( 47.94000)
USGS Quad: MUKILTEO Longitude: 122° 21.4' W (-122.35700)
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.