U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 5
Station ID: 8638671 PUBLICATION DATE: 11/22/2011
Name: LAFAYETTE RIVER
VA
NOAA Chart: 12245 Latitude: 36° 53.1' N ( 36.88422)
USGS Quad: Norfol North Longitude: 76° 16.6' W ( -76.27586)
TO REACH THE STATION FROM THE INTERSECTION OF GRANBY ST AND E 39TH ST IN NORFOLK
PROCEED EAST ON E 39TH ST .3 MI TO THE INTERSECTION WITH HOLLY AVENUE. PROCEED
NORTH ON HOLLY AVENUE 200 FT (61.0 M) THE STATION IS LOCATED ON A PRIVATE PIER
BEHIND 3912 HOLLY AVENUE AND THE BENCH MARKS ARE IN THE GENERAL VICINITY ON E
39TH ST.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 8671 A 2011
DESIGNATION: 863 8671 A
MONUMENTATION: Flange-encased Rod VM#: 19883
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Steel rod OPUS PID:
LATITUDE: 36° 53.0' N ( 36.88407) LONGITUDE: 76° 16.6' W ( -76.27640)
The primary bench mark is a steel rod driven 14.6 m (48 ft) to refusal in the
backyard of 3912 Holly Avenue 21.0 m (68.9 ft) east of a green power junction
box, N of the northeast corner of the residence at 3901 Beach Avenue and 16.3 m
(53.5 ft) west of the end of the pier where the tide station is located. The
mark is approximately 3 inches (8 cm) below ground level surrounded by a
concrete kick block and covered by an aluminum access cover.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 5
Station ID: 8638671 PUBLICATION DATE: 11/22/2011
Name: LAFAYETTE RIVER
VA
NOAA Chart: 12245 Latitude: 36° 53.1' N ( 36.88422)
USGS Quad: Norfol North Longitude: 76° 16.6' W ( -76.27586)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8671 B 2011
DESIGNATION: 863 8671 B
MONUMENTATION: Tidal Station disk VM#: 19884
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Concrete steps OPUS PID:
LATITUDE: 36° 53.0' N ( 36.88344) LONGITUDE: 76° 16.6' W ( -76.27733)
The bench mark is a brass disk located at 268 E 39th St in the first step
leading up from the side walk to a private residence, 7.8 m (25.5 ft) north of
the north curb of E 39th St, 6.4 m (21.1 ft ) southeast of the southwest corner
of the house, 6.2 m (20.5 ft) northwest of a green power junction box.
BENCH MARK STAMPING: 8671 C 2011
DESIGNATION: 863 8671 C
MONUMENTATION: Tidal Station disk VM#: 19885
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Concrete steps OPUS PID:
LATITUDE: 36° 53.0' N ( 36.88294) LONGITUDE: 76° 16.7' W ( -76.27797)
The bench mark is a brass disk located at 257 E 39th St in the first step
leading up from the side walk to a private residence, 9.3 m (30.5 ft) north of
the sill of the front door of the residence, 9.1 m (29.9 ft) south of the south
curb of E 39th St, .18m (.6 ft ) east of inner edge of steps.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 5
Station ID: 8638671 PUBLICATION DATE: 11/22/2011
Name: LAFAYETTE RIVER
VA
NOAA Chart: 12245 Latitude: 36° 53.1' N ( 36.88422)
USGS Quad: Norfol North Longitude: 76° 16.6' W ( -76.27586)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 8671 D 2011
DESIGNATION: 863 8671 D
MONUMENTATION: Tidal Station disk VM#: 19886
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Concrete steps OPUS PID:
LATITUDE: 36° 53.0' N ( 36.88294) LONGITUDE: 76° 16.7' W ( -76.27842)
The bench mark is a brass disk located at 240 E 39th St in the top step leading
up from the side walk to a private residence, 8.0 m (26.4 ft) northeast of a
fire hydrant, 6.9 m (22.8 ft) north of a light pole and 1.7 m (5.7 ft) south
of the south edge of the brick steps.
BENCH MARK STAMPING: 8671 E 2011
DESIGNATION: 863 8671 E
MONUMENTATION: Tidal Station disk VM#: 19887
AGENCY: CO-OPS IDB PID#:
SETTING CLASSIFICATION: Concrete steps OPUS PID:
LATITUDE: 36° 53.0' N ( 36.88261) LONGITUDE: 76° 16.7' W ( -76.27908)
The mark is a brass disk located at 220 E 39th St in the bottom step leading
from the upper side walk to the front porch of a private residence, 9.0 m (29.5
ft) north of street lamp number No 518, 2.2 m (7.3 ft) east of the inside edge
of the western retaining wall surrounding the steps and 0.5 m (1.8 ft) west of
the inner edge of the eastern retaining wall surrounding the steps.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8638671 PUBLICATION DATE: 11/22/2011
Name: LAFAYETTE RIVER
VA
NOAA Chart: 12245 Latitude: 36° 53.1' N ( 36.88422)
USGS Quad: Norfol North Longitude: 76° 16.6' W ( -76.27586)
T I D A L D A T U M S
Tidal datums at LAFAYETTE RIVER based on:
LENGTH OF SERIES: 6 MONTHS
TIME PERIOD: Mar 2011 - Jul 2011 & Sep 2011
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8638610 SEWELLS POINT, HAMPTON ROADS
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 0.916
MEAN HIGH WATER MHW = 0.853
MEAN SEA LEVEL MSL = 0.451
MEAN TIDE LEVEL MTL = 0.447
MEAN LOW WATER MLW = 0.041
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
8671 A 2011 1.759 0.906
8671 B 2011 3.251 2.398
8671 C 2011 3.479 2.626
8671 D 2011 3.705 2.852
8671 E 2011 3.966 3.113
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8638671 PUBLICATION DATE: 11/22/2011
Name: LAFAYETTE RIVER
VA
NOAA Chart: 12245 Latitude: 36° 53.1' N ( 36.88422)
USGS Quad: Norfol North Longitude: 76° 16.6' W ( -76.27586)
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.