U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
To reach the tidal bench marks from the intersection of U.S. Highway 50 and
State Highway 8 on Kent Island, proceed south on State Highway 8 for 3.9 km (2.4
mi) to the access road for Chesapeake Bay Model, Matapeake Marine Terminal, and
the Maryland Department of Natural Resources Police facilities, turn right and
go west for 0.6 km (0.4 mi) to the police facilities area. The bench marks are
located on the police facilities grounds, at the intersection of State Highway 8
and the access road, and at the entrance gate to Matapeake Marine Terminal. The
tide gage and staff were located on the police facilities central pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 1 1972
DESIGNATION: 857 2770 TIDAL 1
MONUMENTATION: Tidal Station disk VM#: 10828
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete sea wall OPUS PID:
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The primary bench mark is a disk set flush in a concrete seawall, in the SE
corner of the southern extension of the police facilities central pier, 13.41 m
(44.0 ft) south of the centerline of the pier, 9.54 m (31.3 ft) east of the SW
corner of the deck on the southern side of the pier, 1.37 m (4.5 ft) SW of the
most northerly chain link fence post on the southerly side of the pier, and 0.18
m (0.6 ft) above the parking lot.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: X 126 1971
DESIGNATION: X 126
MONUMENTATION: Bench Mark disk VM#: 10826
AGENCY: National Geodetic Survey (NGS) IDB PID#: HV0185
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 38° 57.2' N ( 38.95330) LONGITUDE: 76° 20.8' W ( -76.34670)
The bench mark is a disk located at the intersection of State Highway 8 and the
access road, 32.92 m (108.0 ft) NW of the centerline of the highway, 0.61 m (2.0
ft) SW of a metal witness post and 0.3 m (1 ft) SW of pole #11 F. The bench
mark is set level with the ground, crimped to the top of a copper-clad steel rod
driven 24.4 m (80 ft) to refusal and encased in a 6-inch metal pipe.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: Y 126 1971
DESIGNATION: Y 126
MONUMENTATION: Bench Mark disk VM#: 10827
AGENCY: National Geodetic Survey (NGS) IDB PID#: HV0186
SETTING CLASSIFICATION: Copper-clad steel rod OPUS PID:
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is a disk located north of the police facilities area in a
clearing in the woods at the remnants of a radio tower foundation, 40.23 m
(132.0 ft) NE of a chain link fence, 6.40 m (21.0 ft) SW of the centerline of a
path, and 0.43 m (1.4 ft) NW of a metal witness post. The bench mark is set
level with the ground, crimped to the top of a copper-clad steel rod driven 23.2
m (76 ft) to refusal and encased in a 4-inch metal pipe.
BENCH MARK STAMPING: NO 2 1972
DESIGNATION: 857 2770 TIDAL 2
MONUMENTATION: Tidal Station disk VM#: 10829
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete step OPUS PID#: BBDM15
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is a disk set flush in the second concrete step leading from the
abandoned ferry landing to the warehouse, 13.11 m (43.0 ft) NE of the flagpole
on the police facilities grounds, 12.5 m (40.9 ft) SW of the SW curbing
surrounding police boats and the warehouse, 1.71 m (5.6 ft) SE of the most NW
point of the stairs leading to the warehouse, and 0.1 m (0.3 ft) above the
sidewalk.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: NO 3 1972
DESIGNATION: 857 2770 TIDAL 3
MONUMENTATION: Tidal Station disk VM#: 10830
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Concrete culvert OPUS PID:
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is a disk set flush in a concrete culvert that empties rain water
from the warehouse, 32.43 m (106.4 ft) east of the NW corner of the brick
warehouse, 22.34 m (73.3 ft) NE of the NE corner of the brick warehouse, 14.11 m
(46.3 ft) SW of the southerly side or edge of the parking area surrounding the
police barracks, and 0.24 m (0.8 ft) below the ground.
BENCH MARK STAMPING: NO 6 1973
DESIGNATION: 857 2770 TIDAL 6
MONUMENTATION: Tidal Station disk VM#: 10831
AGENCY: US Coast and Geodetic Survey
(USC&GS) IDB PID#:
SETTING CLASSIFICATION: Step OPUS PID#: BBDG52
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is a disk set flush in the top step of the steps leading from the
headquarters to the warehouse, 31.27 m (102.6 ft) SW of the NW corner of the
warehouse, 20.27 m (66.5 ft) NW of the SW corner of the warehouse, 5.64 m (18.5
ft) NW of the flagpole, and 0.06 m (0.2 ft) below the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2770 A 1979
DESIGNATION: 857 2770 A
MONUMENTATION: Tidal Station disk VM#: 10832
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete pier cap OPUS PID:
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is a disk set flush in the NW corner of the central concrete pier
section, 24.81 m (81.4 ft) west of the inshore end of pier, 4.30 m (14.1 ft)
north of the centerline of the pier, and 0.43 m (1.4 ft) NW of a lamp post.
BENCH MARK STAMPING: 2770 B 1979
DESIGNATION: 857 2770 B
MONUMENTATION: Tidal Station disk VM#: 10833
AGENCY: National Ocean Survey (NOS) IDB PID#:
SETTING CLASSIFICATION: Concrete transformer foundation OPUS PID:
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is a disk set flush in the SE corner of a 2 m x 2 m (6 ft x 6 ft)
concrete slab supporting an electric transformer at the main gate entrance to
Matapeake Marine Terminal, 6.86 m (22.5 ft) west of the centerline of the
entrance road to the police facilities, 5.64 m (18.5 ft) NW of the west gate
post, 0.3 m (1.0 ft) SE of the SE corner of the transformer, and 0.18 m (0.6 ft)
above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 857 2270 BOLT
ALIAS: NO STAMPING 1
MONUMENTATION: Bolt VM#: 10834
AGENCY: Unknown IDB PID#:
SETTING CLASSIFICATION: Fire hydrant OPUS PID:
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is the top of the vertical bolt between the casting letters
ANNISTON*ALABAMA,on the east side of the top of the collar of the fire hydrant
on the north side of the police facilities parking lot, 39.35 m (129.1 ft) SE of
the SE corner of the headquarters, 18 m (59 ft) north of the most NE of westerly
median in center of the parking area for the police barracks and the
headquarters, 5.27 m (17.3 ft) NW of the centerline of the paved driveway
leading north to the DNR Police Academy wood frame building, and 0.49 m (1.6 ft)
above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 857 2270 NUT
ALIAS: NO STAMPING 2
MONUMENTATION: See descriptive text VM#: 10835
AGENCY: Unknown IDB PID#:
SETTING CLASSIFICATION: Concrete foundation OPUS PID:
LATITUDE: 38° 57.4' N ( 38.95670) LONGITUDE: 76° 21.3' W ( -76.35500)
The bench mark is the top of the vertical nut securing the radio antenna to the
most easterly concrete foundation on the police facilities grounds, the nut is
the second one clockwise from the antenna brace, and the first nut counter
clockwise from the metal ground of the antenna support, 24.32 m (79.8 ft) SSE of
the NE corner of the DNR Police Academy building, 12 m (39.4 ft) SE of the SE
corner of the DNR Police Academy building, 1.83 m (6.0 ft) south of the north
side of a fence around transmitting tower, and 0.27 m (0.9 ft) above the ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
T I D A L D A T U M S
Tidal datums at MATAPEAKE based on:
LENGTH OF SERIES: 5 YEARS
TIME PERIOD: January 1979 - December 1983
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8574680 BALTIMORE, FORT MCHENRY, PATAPSCO RIVER
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (09/15/1979) = 1.374
MEAN HIGHER HIGH WATER MHHW = 0.452
MEAN HIGH WATER MHW = 0.375
North American Vertical Datum NAVD88 = 0.272
MEAN SEA LEVEL MSL = 0.224
MEAN TIDE LEVEL MTL = 0.219
MEAN LOW WATER MLW = 0.063
MEAN LOWER LOW WATER MLLW = 0.000
LOWEST OBSERVED WATER LEVEL (04/05/1975) = -1.101
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 1 1972 2.289 1.914
X 126 1971 4.761 4.386
Y 126 1971 5.682 5.307
NO 2 1972 2.704 2.329
NO 3 1972 4.668 4.293
NO 6 1973 4.881 4.506
2770 A 1979 2.300 1.925
2770 B 1979 6.853 6.478
857 2270 BOLT 4.042 3.667
857 2270 NUT 6.328 5.953
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 9 of 9
Station ID: 8572770 PUBLICATION DATE: 04/29/2003
Name: MATAPEAKE
MD
NOAA Chart: 12270 Latitude: 38° 57.4' N ( 38.95670)
USGS Quad: KENT ISLAND Longitude: 76° 21.3' W ( -76.35500)
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.