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.