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Bench Mark Sheet for 9418865, MAD RIVER SLOUGH, ARCATA BAY CA

Superseded Epoch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Small blue map location marker Unpublished bench mark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  6

                                                                                
Station ID: 9418865                         PUBLICATION DATE:  07/02/2003
Name:       MAD RIVER SLOUGH, ARCATA BAY                      
            CA
NOAA Chart: 18622                           Latitude:   40° 51.9' N (  40.86500)
USGS Quad:  EUREKA                          Longitude: 124°  8.9' W (-124.14800)


To reach the tidal bench marks from Arcata, exit onto  Samoa Boulevard (Highway
255) and proceed west on Samoa Boulevard for 5 km (3 mi) to the bridge over the
entrance to Mad River Slough.  The bench marks in the vicinity of the RH Emerson
and Son Lumberyard, along the railroad tracks. The tide gage was located on a
free standing structure 12 m (40 ft) SE of the SW corner of the concrete bridge
over the Slough and the staff was on a nearby piling.


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


                 PRIMARY BENCH MARK STAMPING:  J 735 RESET 1970
                         DESIGNATION:          J 735 RESET

MONUMENTATION:           Bench Mark disk                       VM#:         8747
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:  LV0346
SETTING CLASSIFICATION:  Concrete pier                         OPUS PID:        
LATITUDE:   40° 51.9' N (  40.86500)          LONGITUDE: 124°  9.0' W (-124.15000)


The primary bench mark is a disk set flush in the top of the SW concrete pier on
the west end of the Samoa Boulevard Bridge.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 9418865                         PUBLICATION DATE:  07/02/2003
Name:       MAD RIVER SLOUGH, ARCATA BAY                      
            CA
NOAA Chart: 18622                           Latitude:   40° 51.9' N (  40.86500)
USGS Quad:  EUREKA                          Longitude: 124°  8.9' W (-124.14800)


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


                         BENCH MARK STAMPING:  8865 B 1977
                         DESIGNATION:          941 8865 B

MONUMENTATION:           Tidal Station disk                    VM#:         8744
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 51.9' N (  40.86500)          LONGITUDE: 124°  8.9' W (-124.14800)


The bench mark is a disk located 37 m (120 ft) ENE of the east gate post of the
western gate at R.H. Emerson and Son Lumberyard, 17 m (56 ft) NW of the
centerline of Samoa Boulevard, 17 m (55 ft) from the support pole for the fourth
telephone pole west of the Samoa Road Bridge over Mad River on the NW side of
railroad track, and 8.66 m (28.4 ft) SE of fire hydrant on lumberyard property.
The bench mark is crimped to the top of a copper-coated rod driven an
unspecified depth to refusal.



                         BENCH MARK STAMPING:  8865 C 1977
                         DESIGNATION:          941 8865 C

MONUMENTATION:           Tidal Station disk                    VM#:         8745
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 51.9' N (  40.86500)          LONGITUDE: 124°  8.9' W (-124.14800)


The bench mark is a disk located 0.40 km (0.25 mi) west of the west curb of the
Samoa Boulevard Bridge over the slough, 60 m (197 ft) SW of bench mark W 1091
1967, 17 m (55 ft) north from the centerline of Samoa Boulevard, 15 m (49 ft) NW
of the crossing signal control box at railroad crossing No. 5G296.7, 8 m (26 ft)
south of SW corner of concrete truck scale, 6 m (19 ft) NNE of center of
roalroad siding switch and 1 m (4 ft) south of a picket fence.  The bench mark
is crimped to the top of a copper-coated rod driven an unspecified depth to
refusal.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 9418865                         PUBLICATION DATE:  07/02/2003
Name:       MAD RIVER SLOUGH, ARCATA BAY                      
            CA
NOAA Chart: 18622                           Latitude:   40° 51.9' N (  40.86500)
USGS Quad:  EUREKA                          Longitude: 124°  8.9' W (-124.14800)


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


                         BENCH MARK STAMPING:  8865 E 1977
                         DESIGNATION:          941 8865 E

MONUMENTATION:           Tidal Station disk                    VM#:         8746
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 51.9' N (  40.86500)          LONGITUDE: 124°  8.9' W (-124.14800)


The bench mark is a disk located 100.43 m (329.5 ft) SW of bench mark J 734
RESET 1970, 26 m (85 ft) west of the second telephone pole south of the Samoa
Boulevard Bridge over the slough on the NW side of railroad tracks, and 17 (55
ft) NW of the centerline of Samoa Boulevard.  The bench mark is crimped to the
top of a copper-coated rod driven 19.5 m (64 ft) to refusal.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 9418865                         PUBLICATION DATE:  07/02/2003
Name:       MAD RIVER SLOUGH, ARCATA BAY                      
            CA
NOAA Chart: 18622                           Latitude:   40° 51.9' N (  40.86500)
USGS Quad:  EUREKA                          Longitude: 124°  8.9' W (-124.14800)


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


                         BENCH MARK STAMPING:  W 1091 1967
                         DESIGNATION:          W 1091

MONUMENTATION:           Bench Mark disk                       VM#:         8748
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  LV0344
SETTING CLASSIFICATION:  Highline tower foundation             OPUS PID:        
LATITUDE:   40° 51.9' N (  40.86420)          LONGITUDE: 124°  9.2' W (-124.15300)


The bench mark is a disk set in top of the concrete base for the SW steel leg of
the first transmission line tower SW of the bridge over the slough, 26 m (84 ft)
NW of centerline of road, 12 m (39 ft) NW of the NW rail of the main track for
the Northwestern Pacific Railroad, 7 m (24 ft) NE of centerline of gravel road,
and 1 m (3 ft) above the road.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 9418865                         PUBLICATION DATE:  07/02/2003
Name:       MAD RIVER SLOUGH, ARCATA BAY                      
            CA
NOAA Chart: 18622                           Latitude:   40° 51.9' N (  40.86500)
USGS Quad:  EUREKA                          Longitude: 124°  8.9' W (-124.14800)


                            T I D A L   D A T U M S 


Tidal datums at MAD RIVER SLOUGH, ARCATA BAY based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           December 1978 - March 1979
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9419750 CRESCENT CITY, PACIFIC OCEAN


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.326
     MEAN HIGH WATER                            MHW    =  2.105
     MEAN SEA LEVEL                             MSL    =  1.295
     MEAN TIDE LEVEL                            MTL    =  1.258
     MEAN LOW WATER                             MLW    =  0.410
     North American Vertical Datum              NAVD88 =  0.305
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     J 735 RESET 1970                            4.845    2.740
     8865 B 1977                                 3.189    1.084
     8865 C 1977                                 3.435    1.330
     8865 E 1977                                 3.398    1.293
     W 1091 1967                                 4.669    2.564


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

                                                                                
Station ID: 9418865                         PUBLICATION DATE:  07/02/2003
Name:       MAD RIVER SLOUGH, ARCATA BAY                      
            CA
NOAA Chart: 18622                           Latitude:   40° 51.9' N (  40.86500)
USGS Quad:  EUREKA                          Longitude: 124°  8.9' W (-124.14800)


                             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 9418865 MAD RIVER SLOUGH, ARCATA BAY, CA

Revised: 10/15/2013
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services