U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9466217 PUBLICATION DATE: 01/14/2011 Name: MEKORYUK, MEKORYUK RIVER ENTRANCE AK NOAA Chart: 16006 Latitude: 60° 25.0' N ( 60.41670) USGS Quad: NUNIVAK ISLAND B-4 Longitude: 166° 10.0' W (-166.16700) To reach the bench marks from the Mekoryuk runway, proceed 11.8 km (7.3 mi) ENE on Airport Way through the village of Mekoryuk to where the road turns approximately ninety degrees to the right, continue past the curve 0.3 km (0.2 mi) ESE to a short, unnamed access road on the right and the Mekoryuk City small boat harbor. The bench marks are 0.3 km (0.2 mi) south of the harbor between the grassy bluff and rock outcrop and the small rock island 0.3 km (0.2 mi) to the south. The tide house was located on the south side of the grassy bluff and the orifices were south of the rock point. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: TIDE 1951 DESIGNATION: 946 6217 TIDAL 1 MONUMENTATION: Topographic Station disk VM#: 19702 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 60° 23.1' N ( 60.38575) LONGITUDE: 166° 11.1' W (-166.18569) The primary bench mark is set in a rock outcrop, 34.65 m (113.7 ft slope distance) ENE of bench mark 946 6217 TIDAL 2, 31.40 m (103.0 ft) ESE of the erosion prevention rock wall where it begins above the sand beach in the small boat harbor, 18.35 m (60.2 ft) south of a 3/8" zinc anchor bolt projecting 6 cm (0.2 ft) set in rock near approximate high water line, and 3.57 m (11.7 ft) SW of the seaward edge of rocks.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9466217 PUBLICATION DATE: 01/14/2011 Name: MEKORYUK, MEKORYUK RIVER ENTRANCE AK NOAA Chart: 16006 Latitude: 60° 25.0' N ( 60.41670) USGS Quad: NUNIVAK ISLAND B-4 Longitude: 166° 10.0' W (-166.16700) T I D A L B E N C H M A R K S BENCH MARK STAMPING: MEKORYUK I95I DESIGNATION: 946 6217 TIDAL 2 MONUMENTATION: Triangulation Station disk VM#: 19703 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Concrete block OPUS PID: LATITUDE: 60° 23.1' N ( 60.38569) LONGITUDE: 166° 11.2' W (-166.18628) The bench mark is a disk set flush in a 0.34 m (1.12 ft) by 0.25 m (0.82 ft) concrete block, 34.65 m (113.7 ft slope distance) WSW of bench mark 946 6217 TIDAL 1, 29.05 m (95.3 ft) SW of the NE corner of a white unnumbered house at top of approximately 13 m (43 ft) high bluff, and 18.27 m (59.9 ft) east of the SE corner of this same house and 0.14 m (0.05 ft) above ground. BENCH MARK STAMPING: 6217 A 2010 DESIGNATION: 946 6217 A MONUMENTATION: Tidal Station disk VM#: 19704 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 60° 23.1' N ( 60.38542) LONGITUDE: 166° 11.2' W (-166.18639) The bench mark is set in a rock outcrop, 57.01 m (187.0 ft) NNE of bench mark 946 6217 B, 39.55 m (12.8 ft) SW of a 3/8" zinc anchor bolt projecting 6 cm (0.2 ft) set in rock near high water line, and 26.38 m (86.6 ft slope distance) east of the NE corner of an unnumbered gray house.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9466217 PUBLICATION DATE: 01/14/2011 Name: MEKORYUK, MEKORYUK RIVER ENTRANCE AK NOAA Chart: 16006 Latitude: 60° 25.0' N ( 60.41670) USGS Quad: NUNIVAK ISLAND B-4 Longitude: 166° 10.0' W (-166.16700) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 6217 B 2010 DESIGNATION: 946 6217 B MONUMENTATION: Tidal Station disk VM#: 19705 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 60° 23.1' N ( 60.38500) LONGITUDE: 166° 11.2' W (-166.18706) The bench mark is set in a rock outcrop, 57.01 m (187.0 ft) SSW of bench mark 946 6217 A, 19.64 m (64.4 ft slope distance) ESE of the SE corner of an unnumbered gray wood house, and 4.15 m (13.6 ft) west of the seaward edge of rocks. BENCH MARK STAMPING: 6217 C 2010 DESIGNATION: 946 6217 C MONUMENTATION: Tidal Station disk VM#: 19706 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID#: BBBZ39 LATITUDE: 60° 23.0' N ( 60.38353) LONGITUDE: 166° 11.2' W (-166.18736) The bench mark is a disk set in a rock outcrop, 62.3 m (204.4 ft) north of a large boulder near the approximate high waterline at the point projecting into the channel, 18.1 m (59.4 ft slope distance) east of a 4 m (13.1 ft) high grassy slope above the rock point, and 7.46 m (24.5 ft) SSW of seaward edge of rocks near approximate high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9466217 PUBLICATION DATE: 01/14/2011 Name: MEKORYUK, MEKORYUK RIVER ENTRANCE AK NOAA Chart: 16006 Latitude: 60° 25.0' N ( 60.41670) USGS Quad: NUNIVAK ISLAND B-4 Longitude: 166° 10.0' W (-166.16700) T I D A L D A T U M S Tidal datums at MEKORYUK, MEKORYUK RIVER ENTRANCE based on: LENGTH OF SERIES: 3 MONTHS TIME PERIOD: July 2010 - September 2010 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 2.323 MEAN HIGH WATER MHW = 2.149 MEAN SEA LEVEL MSL = 1.177 MEAN TIDE LEVEL MTL = 1.173 MEAN LOW WATER MLW = 0.196 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW TIDE 1951 3.649 1.500 MEKORYUK I95I 12.743 10.594 6217 A 2010 2.874 0.725 6217 B 2010 3.843 1.694 6217 C 2010 3.193 1.044
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9466217 PUBLICATION DATE: 01/14/2011 Name: MEKORYUK, MEKORYUK RIVER ENTRANCE AK NOAA Chart: 16006 Latitude: 60° 25.0' N ( 60.41670) USGS Quad: NUNIVAK ISLAND B-4 Longitude: 166° 10.0' W (-166.16700) 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.