Superseded Bench Mark Sheet for 8630229, LEWIS CREEK VA

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  4

                                                   PUBLICATION DATE:  12/29/1981
Station ID: 8630229                                SUPERCEDED DATE:   04/21/2003
Name:       LEWIS CREEK, CHINCOTEAGUE ISLAND                  
            VIRGINIA
NOAA Chart: 12211                                  Latitude:         37° 56.3' N
USGS Quad:  CHINCOTEAGUE EAST                      Longitude:        75° 22.4' W


To reach the tidal bench marks from the Chincoteague Post Office proceed 0.35
mile north along Main Street to an intersection with Maddox Boulevard and
Barnies Camp Ground, then proceed west (left turn) into Barnies Camp Ground. 
The tide gage and staff were located at the end of Barnies camp ground dock in
Lewis Creek.


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  H 422 1963

MONUMENTATION:           Survey Disk                               VM#:     3252
AGENCY:                                                            PID#:  FW0144
SETTING CLASSIFICATION:  Copper-Clad Deep Rod


The bench mark is at the junction of Maddox Boulevard (State Highway 2113), and
Main Street, 46.6 feet west and across the street from power pole No.
21-521-535, 6.2 feet east of the south corner of a green one-story frame house,
0.5 foot above street level, and projecting 0.1 foot.  The bench mark is crimped
on a copper-coated steel rod driven 56 feet to refusal.



                         BENCH MARK STAMPING:  863 0229 A 1977

MONUMENTATION:           Survey Disk                               VM#:     3250
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in concrete located 250 feet west of the intersection of
Maddox Boulevard and Main Street, 148.3 feet southeast of the eastern face of a
bulkhead, 43.6 feet west of a 0.5 foot elm tree, 21.3 feet northwest of power
pole No. 26P and 0.2 foot below ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  4

                                                   PUBLICATION DATE:  12/29/1981
Station ID: 8630229                                SUPERCEDED DATE:   04/21/2003
Name:       LEWIS CREEK, CHINCOTEAGUE ISLAND                  
            VIRGINIA
NOAA Chart: 12211                                  Latitude:         37° 56.3' N
USGS Quad:  CHINCOTEAGUE EAST                      Longitude:        75° 22.4' W


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  863 0229 B 1977

MONUMENTATION:           Survey Disk                               VM#:     3251
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Monument


The bench mark is set in concrete located 150 feet west of the intersection of
Maddox Boulevard and Main Street, on Barnie's Camp Ground, inside a circular
driveway, 63.3 feet northeast of the easternmost corner of an office building,
20.0 feet southeast of the north corner of an open-sided shed, 3.3 feet
northeast of the east corner of an open-sided shed, and at ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  4

                                                   PUBLICATION DATE:  12/29/1981
Station ID: 8630229                                SUPERCEDED DATE:   04/21/2003
Name:       LEWIS CREEK, CHINCOTEAGUE ISLAND                  
            VIRGINIA
NOAA Chart: 12211                                  Latitude:         37° 56.3' N
USGS Quad:  CHINCOTEAGUE EAST                      Longitude:        75° 22.4' W


                            T I D A L   D A T U M S 


Tidal datums at LEWIS CREEK, CHINCOTEAGUE ISLAND based on:

     LENGTH OF SERIES:      1 MONTH
     TIME PERIOD:           OCTOBER 1977
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8630249 U.S.C.G. Station, Chincoteague 


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in FEET:

     MEAN HIGHER HIGH WATER                     MHHW   =   1.54
     MEAN HIGH WATER                            MHW    =   1.42
     MEAN TIDE LEVEL                            MTL    =   0.76
     MEAN LOW WATER                             MLW    =   0.10
     MEAN LOWER LOW WATER                       MLLW   =   0.00

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     H 422 1963                                  4.51      3.09
     863 0229 A 1977                             3.64      2.22
     863 0229 B 1977                             4.11      2.69


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  4

                                                   PUBLICATION DATE:  12/29/1981
Station ID: 8630229                                SUPERCEDED DATE:   04/21/2003
Name:       LEWIS CREEK, CHINCOTEAGUE ISLAND                  
            VIRGINIA
NOAA Chart: 12211                                  Latitude:         37° 56.3' N
USGS Quad:  CHINCOTEAGUE EAST                      Longitude:        75° 22.4' W


                             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 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.

Return to Top
Products available at 8630229 LEWIS CREEK, VA