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Bench Mark Sheet for 8660983, SOCASTEE BRIDGE SC

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  7

                                                                                
Station ID: 8660983                         PUBLICATION DATE:  06/28/2004
Name:       SOCASTEE BRIDGE                                   
            SC
NOAA Chart: 11535                           Latitude:   33° 41.2' N (  33.68670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  0.3' W ( -79.00500)


To reach the tidal bench marks from the intersection of State Highways 501 and
707 NW of Myrtle Beach, proceed west on State Highway 707 for 11 km (7 mi) to
State Highway 544 and the swing bridge crossing the Intracoastal Waterway.  The
bench marks are north of the bridge along State Highway 544.  The tide gage and
staff were on the fender at the north side of the bridge.


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


                 PRIMARY BENCH MARK STAMPING:  0983 A 1976
                         DESIGNATION:          866 0983 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         3739
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD1619
SETTING CLASSIFICATION:  Wingwall of bridge                    OPUS PID:        
LATITUDE:   33° 41.2' N (  33.68670)          LONGITUDE:  79°  0.3' W ( -79.00500)


The primary bench mark is a disk set in the NE concrete abutment of the State
Highway 544 bridge over the Intracoastal Waterway, 4.57 m (15.0 ft) NE of the
centerline of the highway, 1.22 m (4.0 ft) west of the wooden steps leading
beneath the bridge, 0.61 m (2.0 ft) south of a utility pole, and 0.43 m (1.4 ft)
east of the NE corner of the bridge.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  7

                                                                                
Station ID: 8660983                         PUBLICATION DATE:  06/28/2004
Name:       SOCASTEE BRIDGE                                   
            SC
NOAA Chart: 11535                           Latitude:   33° 41.2' N (  33.68670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  0.3' W ( -79.00500)


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


                         BENCH MARK STAMPING:  SOCASTEE 1934
                         DESIGNATION:          SOCASTEE

MONUMENTATION:           Triangulation Station disk            VM#:         3736
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  DD1617
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 41.3' N (  33.68830)          LONGITUDE:  79°  0.3' W ( -79.00500)


The bench mark is a disk set in a concrete monument near the first house north
of the bridge on the east side of the highway, 21.40 m (70.2 ft) east of a 0.15
m (0.5 ft) high brick wall, 12 m (39 ft) NE of a 0.46 m (1.5 ft) diameter
magnolia tree, 11.28 m (37.0 ft) WSW of a large camilla bush, and 0.21 m (0.7
ft) below ground level.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  7

                                                                                
Station ID: 8660983                         PUBLICATION DATE:  06/28/2004
Name:       SOCASTEE BRIDGE                                   
            SC
NOAA Chart: 11535                           Latitude:   33° 41.2' N (  33.68670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  0.3' W ( -79.00500)


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


                         BENCH MARK STAMPING:  SOCASTEE NO 3 1934
                         DESIGNATION:          SOCASTEE RM 3

MONUMENTATION:           Reference Mark disk                   VM#:         3737
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  DD1620
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 41.3' N (  33.68830)          LONGITUDE:  79°  0.3' W ( -79.00500)


The bench mark is a disk set in a concrete monument near the first house north
of the bridge on the west side of the highway, 17.92 m (58.8 ft) ESE of the
center of the bottom step leading to the house, 15.76 m (51.7 ft) WSW of the
centerline of State Highway 544, 11.49 m (37.7 ft) west of utility pole #1G21,
9.81 m (32.2 ft) NW of a 1 m (3 ft) diameter pine tree, and 4.33 m (14.2 ft) SSW
of the center of a twin magnolia tree.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  7

                                                                                
Station ID: 8660983                         PUBLICATION DATE:  06/28/2004
Name:       SOCASTEE BRIDGE                                   
            SC
NOAA Chart: 11535                           Latitude:   33° 41.2' N (  33.68670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  0.3' W ( -79.00500)


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


                         BENCH MARK STAMPING:  SOCASTEE NO 4 1934
                         DESIGNATION:          SOCASTEE RM 4

MONUMENTATION:           Reference Mark disk                   VM#:         3738
AGENCY:                  US Coast & Geodetic Survey
                         (USC&GS)                                 IDB PID#:  DD1618
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   33° 41.3' N (  33.68830)          LONGITUDE:  79°  0.3' W ( -79.00500)


The bench mark is a disk set in a concrete monument north of the bridge on the
east side of the highway, 30.18 m (99.0 ft) SSW of the SW corner of the screened
porch of a house, 24.69 m (81.0 ft) east of the centerline of State Highway 544,
15.12 m (49.6 ft) south of Bench Mark SOCASTEE 1934, 10.27 m (33.7 ft) SE of a
0.46 m (1.5 ft) diameter magnolia tree, 6.40 m (21.0 ft) north of a cluster of
four pine trees, and at ground level.



                         BENCH MARK STAMPING:  0983 B 1976
                         DESIGNATION:          866 0983 B TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         3740
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD1616
SETTING CLASSIFICATION:  Copper clad steel rod                 OPUS PID:        
LATITUDE:   33° 41.3' N (  33.68830)          LONGITUDE:  79°  0.3' W ( -79.00500)


The bench mark is a disk located in a lawn, 274 m (900 ft) north of the bridge
on the east side of the highway, 22.04 m (72.3 ft) north of utility pole #3-64,
21.52 m (70.6 ft) NNW of a free-standing water spigot, 7.22 m (23.7 ft) east of
the centerline of State Highway 544, and 1.34 m (4.4 ft) west of utility pole
#6a.  The bench mark is set 3 cm (0.1 ft) below ground level, crimped to the top
of a copper-clad steel rod driven 4.6 m (15 ft) to refusal, and encased in a
4-inch PVC pipe and concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  7

                                                                                
Station ID: 8660983                         PUBLICATION DATE:  06/28/2004
Name:       SOCASTEE BRIDGE                                   
            SC
NOAA Chart: 11535                           Latitude:   33° 41.2' N (  33.68670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  0.3' W ( -79.00500)


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


                         BENCH MARK STAMPING:  0983 F 1982
                         DESIGNATION:          866 0983  F TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:         3741
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  DD1622
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   33° 41.4' N (  33.69000)          LONGITUDE:  79°  0.4' W ( -79.00670)


The bench mark is a disk located 73 m (239 ft) west of bench mark 0983 B 1976,
15 m (49 ft) NW of a secondary state road, 13.50 m (44.3 ft) south of the SW
corner of the front porch of a wooden house, 6.64 m (21.8 ft) west of a 0.46 m
(1.5 ft) diameter pecan tree, and 4.36 m (14.3 ft) SSE of a utility pole with
light.  The bench mark is set at ground level, crimped to the top of a stainless
steel rod driven 14.6 m (48 ft) to refusal, and encased in a PVC pipe and
concrete kickblock.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  7

                                                                                
Station ID: 8660983                         PUBLICATION DATE:  06/28/2004
Name:       SOCASTEE BRIDGE                                   
            SC
NOAA Chart: 11535                           Latitude:   33° 41.2' N (  33.68670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  0.3' W ( -79.00500)


                            T I D A L   D A T U M S 


Tidal datums at SOCASTEE BRIDGE based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           October 1976 - December 1976
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  8661139 BUCKSPORT, WACCAMAW RIVER


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

     MEAN HIGHER HIGH WATER                     MHHW   =  0.717
     MEAN HIGH WATER                            MHW    =  0.675
     MEAN SEA LEVEL                             MSL    =  0.402
     MEAN TIDE LEVEL                            MTL    =  0.359
     North American Vertical Datum              NAVD88 =  0.216
     MEAN LOW WATER                             MLW    =  0.042
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     0983 A 1976                                 4.802    4.127
     SOCASTEE 1934                               3.942    3.267
     SOCASTEE NO 3 1934                          3.993    3.318
     SOCASTEE NO 4 1934                          3.897    3.222
     0983 B 1976                                 4.812    4.137
     0983 F 1982                                 5.770    5.095


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  7

                                                                                
Station ID: 8660983                         PUBLICATION DATE:  06/28/2004
Name:       SOCASTEE BRIDGE                                   
            SC
NOAA Chart: 11535                           Latitude:   33° 41.2' N (  33.68670)
USGS Quad:  BUCKSVILLE                      Longitude:  79°  0.3' W ( -79.00500)


                             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.

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Products available at 8660983 SOCASTEE BRIDGE, SC

Revised: 08/08/2018
NOAA / National Ocean Service
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