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Bench Mark Sheet for 9410962, BECHERS BAY, SANTA ROSA ISLAND 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Superseded Epoch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Small blue map location marker Unpublished bench mark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  5

                                                                                
Station ID: 9410962                         PUBLICATION DATE:  05/23/2003
Name:       BECHERS BAY, SANTA ROSA ISLAND                    
            CA
NOAA Chart: 18728                           Latitude:   34°  0.5' N (  34.00830)
USGS Quad:  SANTA ROSA ISLAND NORTH         Longitude: 120°  2.8' W (-120.04700)


To reach the tidal bench marks from Santa Barbara proceed by boat SW for about
61 km (33 nm) across Santa Barbara Channel to Santa Rosa Island and a pier
located at Bechers Bay about 3 km (2 mi) south of Carrington Point.  The bench
marks are on the ranch grounds adjacent to the pier.  The tide gauge and staff
were at the end of the pier.


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


                 PRIMARY BENCH MARK STAMPING:  1 1934
                         DESIGNATION:          941 0962 TIDAL 1

MONUMENTATION:           Tidal Station disk                    VM#:        11745
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   34°  0.5' N (  34.00830)          LONGITUDE: 120°  2.8' W (-120.04700)


The primary bench mark is a disk set in a drill hole on top of a large round
shaped outcrop of rock on the north slope of the first canyon north of the pier,
about 15 m (50 ft) inshore from the mouth of the canyon.



                         BENCH MARK STAMPING:  4 1946
                         DESIGNATION:           941 0962 TIDAL 4

MONUMENTATION:           Tidal Station disk                    VM#:        11746
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   34°  0.5' N (  34.00830)          LONGITUDE: 120°  2.8' W (-120.04700)


The bench mark is a disk set in the top of a round shaped outcrop of rock on the
south slope of the first canyon north of the pier, 56 m (184 ft) north of a gate
just east of the NE corner of the ranch foremans house, and 28 m (92 ft) SSW of
bench mark 1 1934.

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

                                                                                
Station ID: 9410962                         PUBLICATION DATE:  05/23/2003
Name:       BECHERS BAY, SANTA ROSA ISLAND                    
            CA
NOAA Chart: 18728                           Latitude:   34°  0.5' N (  34.00830)
USGS Quad:  SANTA ROSA ISLAND NORTH         Longitude: 120°  2.8' W (-120.04700)


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


                         BENCH MARK STAMPING:  0962 A 1977
                         DESIGNATION:          941 0962 A

MONUMENTATION:           Tidal Station disk                    VM#:        11747
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   34°  0.5' N (  34.00830)          LONGITUDE: 120°  2.8' W (-120.04700)


The bench mark is a disk located in the vicinity of the pier, about 76 m (250
ft) SW of the inshore end of the pier, about 31 m (102 ft) SW of the south end
of a gate to a gravel ramp leading to the  pier, 3 m (9 ft) SE of a wooden fence
to a cattle loading alley, and 0.85 m (2.8 ft) NE of a wire mesh fence.  The
bench mark is set about 9 cm (0.3 ft) below the ground, crimped to the top of a
galvanized steel rod driven 6.7 m (22 ft) to refusal.



                         BENCH MARK STAMPING:  0962 B 1977
                         DESIGNATION:          941 0962 B

MONUMENTATION:           Tidal Station disk                    VM#:        11748
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID:        
LATITUDE:   34°  0.5' N (  34.00830)          LONGITUDE: 120°  2.8' W (-120.04700)


The bench mark is a disk located in the vicinity of an old school house, 130 m
(427 ft) WSW of the gate to the gravel ramp leading to the pier, 46 m (151 ft)
east of the SE corner and in line with the south face of the old school house
(now used as a separate bunk house), 21 m (69 ft) south of the centerline of the
dirt road leading from the pier to the barns, 4 m (13 ft) west of a corner post
in a wooden fence, and 0.43 m (1.4 ft) north of an east-west corral fence. The
bench mark is set 9 cm (0.3 ft) below the ground, crimped to the top of a
galvenized steel rod driven 2.1 m (7 ft) to refusal.

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

                                                                                
Station ID: 9410962                         PUBLICATION DATE:  05/23/2003
Name:       BECHERS BAY, SANTA ROSA ISLAND                    
            CA
NOAA Chart: 18728                           Latitude:   34°  0.5' N (  34.00830)
USGS Quad:  SANTA ROSA ISLAND NORTH         Longitude: 120°  2.8' W (-120.04700)


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


                         BENCH MARK STAMPING:  0962 C 1977
                         DESIGNATION:          941 0962 C

MONUMENTATION:           Tidal Station disk                    VM#:        11749
AGENCY:                  National Ocean Survey (NOS)           IDB PID#:        
SETTING CLASSIFICATION:  Galvanized steel rod                  OPUS PID#: BBCR84
LATITUDE:   34°  0.5' N (  34.00830)          LONGITUDE: 120°  2.8' W (-120.04700)


The bench mark is a disk located near the ranch foremans house, 112 m (367 ft)
NW of a gate to the gravel ramp leading to the pier, 24 m (79 ft) SSW of the
west end of the gate located just east of the NE corner of the ranch foremans
house, 6.80 m (22.3 ft) east of the SE corner of the house and in line with the
front of the house, 5.15 m (16.9 ft) north of the SE yard fence corner, and 0.58
m (1.9 ft) east of the wooden yard fence. The bench mark is set 9 cm (0.3 ft)
below the ground, crimped to the top of a galvanized steel rod driven 1.8 m (6
ft) to refusal.

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

                                                                                
Station ID: 9410962                         PUBLICATION DATE:  05/23/2003
Name:       BECHERS BAY, SANTA ROSA ISLAND                    
            CA
NOAA Chart: 18728                           Latitude:   34°  0.5' N (  34.00830)
USGS Quad:  SANTA ROSA ISLAND NORTH         Longitude: 120°  2.8' W (-120.04700)


                            T I D A L   D A T U M S 


Tidal datums at BECHERS BAY, SANTA ROSA ISLAND based on:

     LENGTH OF SERIES:      8 MONTHS
     TIME PERIOD:           October 1977 - May 1978
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9410660 LOS ANGELES, OUTER HARBOR


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

     MEAN HIGHER HIGH WATER                     MHHW   =  1.567
     MEAN HIGH WATER                            MHW    =  1.346
     MEAN TIDE LEVEL                            MTL    =  0.820
     MEAN SEA LEVEL                             MSL    =  0.814
     MEAN LOW WATER                             MLW    =  0.295
     MEAN LOWER LOW WATER                       MLLW   =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     1 1934                                      7.188    5.842
     4 1946                                      7.299    5.953
     0962 A 1977                                15.510   14.164
     0962 B 1977                                16.560   15.214
     0962 C 1977                                15.576   14.230


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

                                                                                
Station ID: 9410962                         PUBLICATION DATE:  05/23/2003
Name:       BECHERS BAY, SANTA ROSA ISLAND                    
            CA
NOAA Chart: 18728                           Latitude:   34°  0.5' N (  34.00830)
USGS Quad:  SANTA ROSA ISLAND NORTH         Longitude: 120°  2.8' W (-120.04700)


                             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 9410962 BECHERS BAY, SANTA ROSA ISLAND, CA

Revised: 08/08/2018
NOAA / National Ocean Service
Web site owner: Center for Operational Oceanographic Products and Services