U.S. DEPARTMENT OF COMMERCE
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National Ocean Service
Datums Page Page 1 of 5
Station ID: 8571616 PUBLICATION DATE: 04/04/2012
Name: SALISBURY, WICOMICO RIVER
MD
NOAA Chart: 12261 Latitude: 38° 21.9' N ( 38.36500)
USGS Quad: DELMAR Longitude: 75° 36.4' W ( -75.60670)
To reach the tidal bench marks from U.S. Highway 50 and Mill Street in
Salisbury, Maryland, proceed west on U.S. Highway 50 to the U.S. Highway 50
bridge over Wicomico River. The bench marks are south of U.S. Highway 50 along
Mill and Main Streets. The tide gage and staff were on the south side of the
U.S. Highway 50 bridge over Wicomico River. Note: A portion of Main Street
is closed to vehicular traffic (pedestrian shopping mall).
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 4 1931
DESIGNATION: 857 1616 TIDAL 4
MONUMENTATION: Tidal Station disk VM#: 15534
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HU0529
SETTING CLASSIFICATION: Granite foundation OPUS PID:
LATITUDE: 38° 21.9' N ( 38.36500) LONGITUDE: 75° 36.4' W ( -75.60670)
The primary bench mark is a disk set vertically in the north face of the granite
foundation of the building at the SE corner of the intersection of Main Street
and Division Street, 16 m (52 ft) east of the centerline of Division Street, and
0.46 m (1.5 ft) above the sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8571616 PUBLICATION DATE: 04/04/2012
Name: SALISBURY, WICOMICO RIVER
MD
NOAA Chart: 12261 Latitude: 38° 21.9' N ( 38.36500)
USGS Quad: DELMAR Longitude: 75° 36.4' W ( -75.60670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1931
DESIGNATION: 857 1616 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 15535
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HU0530
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 38° 21.9' N ( 38.36500) LONGITUDE: 75° 36.4' W ( -75.60670)
The bench mark is a disk set vertically in the SE corner of the concrete
foundation of the bridge tenders house at the Main Street bridge over the
Wicomico River, 53 m (175 ft) west of the intersection of Main Street and Mill
Street, and 0.3 m (1 ft) above the ground.
BENCH MARK STAMPING: 22 BALTO 1900 MARYLAND
DESIGNATION: 22
MONUMENTATION: Survey disk VM#: 15536
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HU0527
SETTING CLASSIFICATION: Stone wall OPUS PID:
LATITUDE: 38° 21.9' N ( 38.36500) LONGITUDE: 75° 36.4' W ( -75.60670)
The bench mark is a disk set vertically in the west face at the NW corner of the
stone wall of the County Courthouse Building at the NE corner of the
intersection of Main Street and Division Street, and 1 m (2 ft) above the
ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8571616 PUBLICATION DATE: 04/04/2012
Name: SALISBURY, WICOMICO RIVER
MD
NOAA Chart: 12261 Latitude: 38° 21.9' N ( 38.36500)
USGS Quad: DELMAR Longitude: 75° 36.4' W ( -75.60670)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 6 1937
DESIGNATION: 857 1616 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 15537
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#: HU0526
SETTING CLASSIFICATION: Concrete wall OPUS PID:
LATITUDE: 38° 21.9' N ( 38.36500) LONGITUDE: 75° 36.4' W ( -75.60670)
The bench mark is a disk set in the top of a concrete wall along the east side
of the steps leading to the main entrance of Maude Toulson Federal Building
(U.S. Post Office), 10.33 m (33.9 ft) north of the centerline of Main Street,
and 4.02 m (13.2 ft) north of the curb.
BENCH MARK STAMPING: 1616 A 1989
DESIGNATION: 857 1616 A
MONUMENTATION: Bench Mark disk VM#: 15538
AGENCY: National Ocean Service (NOS) IDB PID#:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID#: BBDG54
LATITUDE: 38° 21.9' N ( 38.36500) LONGITUDE: 75° 36.4' W ( -75.60670)
The bench mark is a disk located in the parking lot SE of the U.S. Highway 50
bridge over Wicomico River, 33.07 m (108.5 ft) WSW of the Mill Street curb, 11 m
(35 ft) SSW of the SW corner of the bridge tenders building, 2.93 m (9.6 ft)
east of the concrete bulkhead on Wicomico River, 1.22 m (4.0 ft) north of the
second wooden rail post of the parking lot railing, and 0.73 m (2.4 ft) north of
a witness post. The bench mark is 0.09 m (0.3 ft) below the ground, crimped to
a stainless steel rod, driven 15 m (48 ft) to refusal, and encased in a 6-inch
PVC pipe and concrete kickblock.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8571616 PUBLICATION DATE: 04/04/2012
Name: SALISBURY, WICOMICO RIVER
MD
NOAA Chart: 12261 Latitude: 38° 21.9' N ( 38.36500)
USGS Quad: DELMAR Longitude: 75° 36.4' W ( -75.60670)
T I D A L D A T U M S
Tidal datums at SALISBURY, WICOMICO RIVER based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: April 1989 - June 1989
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8571892 CAMBRIDGE, CHOPTANK RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 1.054
MEAN HIGH WATER MHW = 1.008
North American Vertical Datum NAVD88 = 0.579
MEAN SEA LEVEL MSL = 0.559
MEAN TIDE LEVEL MTL = 0.529
MEAN LOW WATER MLW = 0.050
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 4 1931 6.075 5.067
NO 3 1931 2.034 1.026
22 BALTO 1900 MARYLAND 7.302 6.294
6 1937 2.609 1.601
1616 A 1989 1.632 0.624
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8571616 PUBLICATION DATE: 04/04/2012
Name: SALISBURY, WICOMICO RIVER
MD
NOAA Chart: 12261 Latitude: 38° 21.9' N ( 38.36500)
USGS Quad: DELMAR Longitude: 75° 36.4' W ( -75.60670)
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.