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Datums Page Page 1 of 5
Station ID: 8669338 PUBLICATION DATE: 02/05/2004
Name: BROAD CREEK
SC
NOAA Chart: 11516 Latitude: 32° 11.1' N ( 32.18500)
USGS Quad: BLUFFTON Longitude: 80° 45.2' W ( -80.75330)
To reach the tidal bench marks from the east end of the U.S. Highway 278 bridge
over Skull Creek (ICWW), proceed 3.5 km (2.2 mi) east on U.S. Highway 278, then
proceed SW on County Road S-7-79 for 3.1 km (1.9 mi), then proceed south on
S-7-336 for 1.0 km (0.6 mi), then proceed NE on County Road S-7-245 for 0.5 km
(0.3 mi), then proceed south on a sand road for 0.5 km (0.3 mi) to the residence
of E.C. Jackson. The bench marks are along the sand road leading to the Jackson
residence. The tide gage and staff were located at the SE corner of Jackson's
pier.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 9338 D 1979
DESIGNATION: 866 9338 D TIDAL
MONUMENTATION: Tidal Station disk VM#: 4623
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2044
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 11.2' N ( 32.18670) LONGITUDE: 80° 45.4' W ( -80.75670)
The bench mark is a disk located near a wooden fence just west of the
intersection of two sand roads, 20 m (66 ft) SW of the sand drive that leads
into the private residence west of the intersection, 6 m (20 ft) SE of a utility
pole with a transformer, 4.85 m (15.9 ft) NW of the centerline of the sand road,
3.29 m (10.8 ft) SSE of the wooden fence, and 0.85 m (2.8 ft) north of an
underground cable access box. The bench mark is 0.03 m (0.1 ft) above 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 2 of 5
Station ID: 8669338 PUBLICATION DATE: 02/05/2004
Name: BROAD CREEK
SC
NOAA Chart: 11516 Latitude: 32° 11.1' N ( 32.18500)
USGS Quad: BLUFFTON Longitude: 80° 45.2' W ( -80.75330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9338 E 1979
DESIGNATION: 866 9338 E TIDAL
MONUMENTATION: Tidal Station disk VM#: 4624
AGENCY: National Ocean Survey (NOS) IDB PID:
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 11.1' N ( 32.18500) LONGITUDE: 80° 45.2' W ( -80.75330)
The bench mark is a disk located west of the sand road that leads south from
County Road S-7-245, 9.78 m (32.1 ft) north of the centerline of a sand
driveway, 7.68 m (25.2 ft) west of the centerline of the sand road, 4.51 m (14.8
ft) ENE of a twin oak tree, 0.67 m (2.2 ft) SSE of the corner post of a fence,
and 0.58 m (1.9 ft) south of a concrete property marker. The bench mark is 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.
BENCH MARK STAMPING: 9338 F 1979
DESIGNATION: 866 9338 F TIDAL
MONUMENTATION: Tidal Station disk VM#: 4625
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2045
SETTING CLASSIFICATION: Stainless steel rod OPUS PID:
LATITUDE: 32° 11.3' N ( 32.18830) LONGITUDE: 80° 45.3' W ( -80.75500)
The bench mark is a disk located near a chain link fence on the east side of the
sand road leading south from S-7-245, 73 m (240 ft) NE of bench mark 9338 E
1979, 14.36 m (47.1 ft) NNW of the southern corner of the fence, 6.64 m (21.8
ft) ENE of the centerline of the sand road, 0.85 m (2.8 ft) south of a utility
pole with a transformer, and 0.21 m (0.7 ft) west of the chainlink fence. The
bench mark is 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 3 of 5
Station ID: 8669338 PUBLICATION DATE: 02/05/2004
Name: BROAD CREEK
SC
NOAA Chart: 11516 Latitude: 32° 11.1' N ( 32.18500)
USGS Quad: BLUFFTON Longitude: 80° 45.2' W ( -80.75330)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 9338 G 1981
DESIGNATION: 866 9338 G TIDAL
MONUMENTATION: Tidal Station disk VM#: 4626
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2043
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 11.1' N ( 32.18500) LONGITUDE: 80° 45.4' W ( -80.75670)
The bench mark is a disk set in a 0.30 m (1.0 ft) diameter concrete monument,
located 106 m (348 ft) SW of bench mark 9338 D 1979, 21.98 m (72.1 ft) SE of the
SE corner of a brick house, 8.53 m (28.0 ft) NNW of the creosote corner post of
a wire fence, and 3.05 m (10.0 ft) NE of the centerline of the driveway to the
brick house.
BENCH MARK STAMPING: 9338 H 1981
DESIGNATION: 866 9338 H TIDAL
MONUMENTATION: Tidal Station disk VM#: 4627
AGENCY: National Ocean Survey (NOS) IDB PID#: CK2042
SETTING CLASSIFICATION: Concrete monument OPUS PID:
LATITUDE: 32° 11.3' N ( 32.18830) LONGITUDE: 80° 45.4' W ( -80.75670)
The bench mark is a disk set in a 0.30 m (1.0 ft) diameter concrete monument,
170.08 m (558.0 ft) NNW of bench mark 9338 F 1979, 10.88 m (35.7 ft) NNW of the
centerline of County Road S-7-245, 3.96 m (13.0 ft) NNW of a utility pole, and
0.52 m (1.7 ft) east of a guy wire anchor.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 5
Station ID: 8669338 PUBLICATION DATE: 02/05/2004
Name: BROAD CREEK
SC
NOAA Chart: 11516 Latitude: 32° 11.1' N ( 32.18500)
USGS Quad: BLUFFTON Longitude: 80° 45.2' W ( -80.75330)
T I D A L D A T U M S
Tidal datums at BROAD CREEK based on:
LENGTH OF SERIES: 1 MONTH
TIME PERIOD: February 1979 - February 1979
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 8667999 BEAUFORT
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.474
MEAN HIGH WATER MHW = 2.351
North American Vertical Datum NAVD88 = 1.346
MEAN SEA LEVEL MSL = 1.259
MEAN TIDE LEVEL MTL = 1.211
MEAN LOW WATER MLW = 0.071
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
9338 D 1979 5.105 2.754
9338 E 1979 6.182 3.831
9338 F 1979 6.086 3.735
9338 G 1981 5.302 2.951
9338 H 1981 6.372 4.021
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 5
Station ID: 8669338 PUBLICATION DATE: 02/05/2004
Name: BROAD CREEK
SC
NOAA Chart: 11516 Latitude: 32° 11.1' N ( 32.18500)
USGS Quad: BLUFFTON Longitude: 80° 45.2' W ( -80.75330)
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.
Station Location
Published bench mark
Unpublished bench mark
