Superseded Bench Mark Sheet for 8555388, MURDERKILL RIVER ENTRANCE DE

Present Epoch

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  5

                                                   PUBLICATION DATE:  10/15/1986
Station ID: 8555388                                SUPERCEDED DATE:   04/21/2003
Name:       BOWERS, MURDERKILL RIVER ENTRANCE, DELAWARE BAY   
            DELAWARE
NOAA Chart: 12304                                  Latitude:         39°  3.5' N
USGS Quad:  FREDERICA                              Longitude:        75° 23.8' W


To reach the tidal bench marks from the intersection of U.S. Highway 113 and
Bowers Beach Road north of Frederica, proceed 3.5 miles (5.6 km) east on Bowers
Beach Road to Bowers, turn right on Hubbard Avenue and proceed 0.1 mile (0.2 km)
to Murderkill Avenue, turn left onto Murderkill Avenue and proceed 0.1 mile (0.2
km) to a triple boat launching ramp.  The bench marks are located along
Murderkill Avenue, Hubbard Avenue, and Bowers Beach Road.  The gage and staff
were located on the bulkhead adjacent to easternmost of three boat launching
ramps.


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


                 PRIMARY BENCH MARK STAMPING:  NO 2 1953

MONUMENTATION:           Survey Disk                               VM#:     2995
AGENCY:                                                            PID#:  JU1052
SETTING CLASSIFICATION:  Concrete Foundation


The bench mark is set flush in a concrete foundation at the NE corner of the
Dock Spot Restaurant on the south side of Murderkill Avenue, 212 feet (65 m)
east of the intersection of Hubbard Avenue and Murderkill Avenues, 77.0 feet
(23.5 m) west of a single boat launching ramp, 57.5 feet (17.5 m) south of the
centerline of Murderkill Avenue, and 51.3 feet (15.6 m) SE of a telephone pole.



                         BENCH MARK STAMPING:  P 36 1963

MONUMENTATION:           Survey Disk                               VM#:     2996
AGENCY:                                                            PID#:  JU1047
SETTING CLASSIFICATION:  Concrete Foundation


The bench mark is set flush in the atop a concrete foundation of the Murderkill
River Rear Range light on south side of Bowers Beach Road, 0.45 mile (0.72 km)
west of the intersection of Hubbard Avenue and Bowers Beach Road, 51.6 feet
(15.7 m) south of the centerline of Bowers Beach Road and 1.0 foot (0.3 m) from
the NW corner of the NW foot of the tower.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  5

                                                   PUBLICATION DATE:  10/15/1986
Station ID: 8555388                                SUPERCEDED DATE:   04/21/2003
Name:       BOWERS, MURDERKILL RIVER ENTRANCE, DELAWARE BAY   
            DELAWARE
NOAA Chart: 12304                                  Latitude:         39°  3.5' N
USGS Quad:  FREDERICA                              Longitude:        75° 23.8' W


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


                         BENCH MARK STAMPING:  5388 A 1983

MONUMENTATION:           Survey Disk                               VM#:     2997
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Foundation


The bench mark is set flush in the western most concrete foundation of a triple
boat launching ramp between Faulkner's Headboat Building and the U.S. Coast
Guard Auxiliary building, 81.4 feet (24.8 m) north of the end of the boat ramp
pier, 46.9 feet (14.3 m) east of the NE corner of a storage shed located at the
rear of Faulkner's Headboat building and 17.6 feet (5.4 m) east of the west side
of the triple boat ramp.



                         BENCH MARK STAMPING:  5388 B 1983

MONUMENTATION:           Survey Disk                               VM#:     2998
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Retaining Wall


The bench mark is set flush in a retaining wall at the residence of #138 Hubbard
Avenue, 42.3 feet (12.9 m) SW of the center of a T-intersection of Hubbard
Avenue and Murderkill Avenue, 22.3 feet (6.8 m) north of the NE corner of a
brown and white shingled building and 19.0 feet (5.8 m) west of the centerline
of Hubbard Avenue.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  5

                                                   PUBLICATION DATE:  10/15/1986
Station ID: 8555388                                SUPERCEDED DATE:   04/21/2003
Name:       BOWERS, MURDERKILL RIVER ENTRANCE, DELAWARE BAY   
            DELAWARE
NOAA Chart: 12304                                  Latitude:         39°  3.5' N
USGS Quad:  FREDERICA                              Longitude:        75° 23.8' W


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


                         BENCH MARK STAMPING:  5388 C 1983

MONUMENTATION:           Survey Disk                               VM#:     2999
AGENCY:                                                            PID:         
SETTING CLASSIFICATION:  Concrete Septic Tank


The bench mark is set flush in the NE corner of septic tank behind Bowers
Country Store on Hubbard Avenue, 125 feet (38 m) west of the centerline of
Hubbard Avenue, 34.9 feet(10.6 m) NW of SW corner of the Bowers Country Store,
and 31.0 feet (9.4 m) south of the nearest telephone pole north of the bench
mark.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  5

                                                   PUBLICATION DATE:  10/15/1986
Station ID: 8555388                                SUPERCEDED DATE:   04/21/2003
Name:       BOWERS, MURDERKILL RIVER ENTRANCE, DELAWARE BAY   
            DELAWARE
NOAA Chart: 12304                                  Latitude:         39°  3.5' N
USGS Quad:  FREDERICA                              Longitude:        75° 23.8' W


                            T I D A L   D A T U M S 


Tidal datums at BOWERS, MURDERKILL RIVER ENTRANCE, DELAWARE BAY based on:

     LENGTH OF SERIES:      2 MONTHS
     TIME PERIOD:           SEPTEMBER-OCTOBER 1984
     TIDAL EPOCH:           1960-1978
     CONTROL TIDE STATION:  8557380 LEWES, DE


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

     HIGHEST OBSERVED WATER LEVEL (04/24/1983)         =   7.36
     MEAN HIGHER HIGH WATER                     MHHW   =   5.69
     MEAN HIGH WATER                            MHW    =   5.27
     MEAN TIDE LEVEL                            MTL    =   2.71
     MEAN LOW WATER                             MLW    =   0.15
     MEAN LOWER LOW WATER                       MLLW   =   0.00
     LOWEST  OBSERVED WATER LEVEL (04/06/1985)         =  -1.67

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In FEET above:

     Stamping or Designation                    MLLW        MHW

     NO 2 1953                                   6.94      1.67
     P 36 1963                                   9.26      3.99
     5388 A 1983                                 7.30      2.03
     5388 B 1983                                 8.39      3.12
     5388 C 1983                                 9.07      3.80


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  5

                                                   PUBLICATION DATE:  10/15/1986
Station ID: 8555388                                SUPERCEDED DATE:   04/21/2003
Name:       BOWERS, MURDERKILL RIVER ENTRANCE, DELAWARE BAY   
            DELAWARE
NOAA Chart: 12304                                  Latitude:         39°  3.5' N
USGS Quad:  FREDERICA                              Longitude:        75° 23.8' 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 8555388 MURDERKILL RIVER ENTRANCE, DE