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Bench Mark Sheet for 9418817, Samoa, Humboldt 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  7

                                                                                
Station ID: 9418817                         PUBLICATION DATE:  07/03/2014
Name:       SAMOA, HUMBOLDT BAY                               
            CA
NOAA Chart: 18662                           Latitude:   40° 49.6' N (  40.82670)
USGS Quad:  EUREKA                          Longitude: 124° 10.8' W (-124.18000)


To reach the tidal bench marks from U. S. Highway 101 in Eureka, exit at Highway
255, continue 3 km (2 mi) west until a T intersection, turn left and travel 2.8
km (1.7 mi), turn left on Lousiana-Pacific Boulevard, at T intersection turn
left, then right at first stop sign to Lousiana-Pacific main gate (No. 6), 
continue to flashing red light, turn left and stay on road until after it curves
to right, 46 m (150 ft) after the curve veer to the right.  The bench marks are
located in the vicinity, and the tide gauge and staff were located on the inside
corner of north end of dock.


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


                 PRIMARY BENCH MARK STAMPING:  8817 B 1978
                         DESIGNATION:          941 8817 B

MONUMENTATION:           Tidal Station disk                    VM#:        11961
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   40° 49.3' N (  40.82122)          LONGITUDE: 124° 10.8' W (-124.18014)


The primary bench mark is a disk located 2.59 m (8.5 ft) MME from the old street
light, and 2.13 m (7 ft) north from the edge of the road. The bench mark is set
15 cm (0.5 ft) below grade, crimped to the top of a galvanized rod driven 19.2 m
(63 ft) to refusal, and encased in concrete and white PVC pipe.

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

                                                                                
Station ID: 9418817                         PUBLICATION DATE:  07/03/2014
Name:       SAMOA, HUMBOLDT BAY                               
            CA
NOAA Chart: 18662                           Latitude:   40° 49.6' N (  40.82670)
USGS Quad:  EUREKA                          Longitude: 124° 10.8' W (-124.18000)


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


                         BENCH MARK STAMPING:  NO 2 1962
                         DESIGNATION:          941 8817 TIDAL 2

MONUMENTATION:           Tidal Station disk                    VM#:        11960
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  LV0352
SETTING CLASSIFICATION:  Concrete foundation                   OPUS PID#: LV0352
LATITUDE:   40° 49.1' N (  40.81800)          LONGITUDE: 124° 10.8' W (-124.18078)


The bench mark is located in the south corner of an abandoned 14  x 18  concrete
filter screen box , 70.00 m (229.7 ft) SE of the south corner of the blacksmith
and machine shop of the Louisiana Pacific Lumber Company, 47.00 m (154.2 ft) ENE
of the center of a pedestrian gate, and 16.70 m (54.8 ft) SE of the center of
the road.

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

                                                                                
Station ID: 9418817                         PUBLICATION DATE:  07/03/2014
Name:       SAMOA, HUMBOLDT BAY                               
            CA
NOAA Chart: 18662                           Latitude:   40° 49.6' N (  40.82670)
USGS Quad:  EUREKA                          Longitude: 124° 10.8' W (-124.18000)


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


                         BENCH MARK STAMPING:  F 735 1944
                         DESIGNATION:          F 735

MONUMENTATION:           Tidal Station disk                    VM#:        11963
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  LV0351
SETTING CLASSIFICATION:  Concrete post                         OPUS PID:        
LATITUDE:   40° 49.3' N (  40.82228)          LONGITUDE: 124° 10.6' W (-124.17697)


The bench mark is a disk set on concrete post located 39.01 m (128 ft) west of a
power pole with two guy wires, 7.31 m (24 ft) north of the centerline of the
road, 0.91 m (3 ft) south of a point directly under a cable line, and 0.61 m (2
ft) east of a witness post, and 0.06 m (0.2 ft) above the ground. 

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

                                                                                
Station ID: 9418817                         PUBLICATION DATE:  07/03/2014
Name:       SAMOA, HUMBOLDT BAY                               
            CA
NOAA Chart: 18662                           Latitude:   40° 49.6' N (  40.82670)
USGS Quad:  EUREKA                          Longitude: 124° 10.8' W (-124.18000)


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


                         BENCH MARK STAMPING:  Z 109 1967
                         DESIGNATION:          Z 1091

MONUMENTATION:           Tidal Station disk                    VM#:        11964
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  LV0350
SETTING CLASSIFICATION:  Copper-clad steel rod                 OPUS PID:        
LATITUDE:   40° 49.7' N (  40.82867)          LONGITUDE: 124° 10.3' W (-124.17236)


The bench mark is a disk located 13 m (42 ft) west of centerline of a road, 0.3
m (1 ft) north of a power pole with guy wire, and 0.3 m (1 ft) south of a
witness post. The bench mark is set 0.3 m (1 ft) above ground, crimped to the
top of a copper-clad rod driven to refusal at 37.5 m (123 ft), and encased in a
concrete post projecting 9 cm (0.3 ft) above ground.

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

                                                                                
Station ID: 9418817                         PUBLICATION DATE:  07/03/2014
Name:       SAMOA, HUMBOLDT BAY                               
            CA
NOAA Chart: 18662                           Latitude:   40° 49.6' N (  40.82670)
USGS Quad:  EUREKA                          Longitude: 124° 10.8' W (-124.18000)


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


                         BENCH MARK STAMPING:  W 1403 1988
                         DESIGNATION:          W 1403

MONUMENTATION:           Metal Rod                             VM#:        20930
AGENCY:                  National Geodetic Survey (NGS)        IDB PID#:  LV0629
SETTING CLASSIFICATION:  Stainless steel rod                   OPUS PID:        
LATITUDE:   40° 49.2' N (  40.81967)          LONGITUDE: 124° 10.4' W (-124.17394)


The bench mark is a metal rod located 87.30 m (286.4 ft) SW of the center of a
wire gate, 13.70 m  (44.9 ft) SE of the centerline of the highway, 0.30 m (1.0
ft) NW of a witness post and fence, and 0.30 m (1.0 ft) above the level of the
highway.  The datum point is 30 cm (1.0 ft) below grade, crimped to a stainless
steel rod driven 15.9 m (52 ft) to unknown refusual, encased in a 5-in logo cap.


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

                                                                                
Station ID: 9418817                         PUBLICATION DATE:  07/03/2014
Name:       SAMOA, HUMBOLDT BAY                               
            CA
NOAA Chart: 18662                           Latitude:   40° 49.6' N (  40.82670)
USGS Quad:  EUREKA                          Longitude: 124° 10.8' W (-124.18000)


                            T I D A L   D A T U M S 


Tidal datums at SAMOA, HUMBOLDT BAY based on:

     LENGTH OF SERIES:      3 MONTHS
     TIME PERIOD:           December 2010 - February 2011
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9418767 NORTH SPIT, HUMBOLDT BAY


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

     MEAN HIGHER HIGH WATER                     MHHW   =  2.245
     MEAN HIGH WATER                            MHW    =  2.026
     MEAN SEA LEVEL                             MSL    =  1.215
     MEAN TIDE LEVEL                            MTL    =  1.211
     MEAN LOW WATER                             MLW    =  0.395
     North American Vertical Datum              NAVD88 =  0.219
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     8817 B 1978                                 5.629    3.603
     NO 2 1962                                   3.465    1.439
     F 735 1944                                  5.312    3.286
     Z 109 1967                                  4.974    2.948
     W 1403 1988                                 8.022    5.996


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

                                                                                
Station ID: 9418817                         PUBLICATION DATE:  07/03/2014
Name:       SAMOA, HUMBOLDT BAY                               
            CA
NOAA Chart: 18662                           Latitude:   40° 49.6' N (  40.82670)
USGS Quad:  EUREKA                          Longitude: 124° 10.8' W (-124.18000)


                             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 9418817 Samoa, Humboldt Bay, CA

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