U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9450623 PUBLICATION DATE: 07/31/2014 Name: BIG SALT LAKE, ALBENO BAY AK NOAA Chart: 17407 Latitude: 55° 36.0' N ( 55.60000) USGS Quad: PETERSBURG Longitude: 132° 57.0' W (-132.95000) To reach the bench marks from Sitka, AK via boat, proceed SSW through Sitka Sound for 25.0 km (13.5 NM) to Biorka Island, then turn SE and proceed 100 km (54 NM) to Cape Ommaney, turn ESE and proceed 44.4 km (24.0 NM) through Cape Decision to Warren Channel, turn SSE and proceed through Warren Channel for 27.8 km (15.0 NM) to Cape Lynch, turn SE and proceed 15.0 kn (8.1 NM) through Bocas de Finas to Pt. Disconocida, then turn SE and proceed 16.0 km (9.34 NM) accross Gulf of Esquibel, proceed SE 5.00 km (3.11 NM) through San Christoval Channel to San christoval Rock, turn ENE and proceed 10.5 km (6.5 NM) through Shinuku Inlet, proceed 2.90 kn (1.61 NM) through northern tidal entrance of Big Salt Lake, turn ESE and proceed 4.50 km (2.80 NM) through small islands into Big Salt Lake, turn NE and proceed 1.87 km (1.16 NM) further into the lake. The bench marks are located close to the treeline on the western shore approximately half way up the first NE leg of Big Salt Lake. The tide staff was located along the shore, approximately 250.0 m (820.0 ft) south of a small isthmus along the eastern shore, and the gauge and benchmarks were installed in the vicinity. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 0623 A 2008 DESIGNATION: 945 0623 A MONUMENTATION: Tidal Station disk VM#: 18690 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Bedrock OPUS PID: LATITUDE: 55° 36.1' N ( 55.60182) LONGITUDE: 133° 1.7' W (-133.02840) The bench mark is a disk set in bedrock 1.5 km (0.9 nm) bearing 256 degrees T (236 degrees m) from a small cove on the other side of Big Salt Lake, 90 km (295 nm) bearing 185 degrees T (205 degrees M) from rocky outcropping at the bend in the northern shoreline, 0.40 km (0.25 nm) bearing 040 degrees T (020 degrees M) from the southern point of the shoreline, 1.00 m (3.3 ft) from the treeline, and 1.50 m (4.9 ft) above the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9450623 PUBLICATION DATE: 07/31/2014 Name: BIG SALT LAKE, ALBENO BAY AK NOAA Chart: 17407 Latitude: 55° 36.0' N ( 55.60000) USGS Quad: PETERSBURG Longitude: 132° 57.0' W (-132.95000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0623 B 2008 DESIGNATION: 945 0623 B MONUMENTATION: Tidal Station disk VM#: 18697 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 55° 37.1' N ( 55.61864) LONGITUDE: 133° 1.7' W (-133.02840) The bench mark is a disk set flush in a 1 m x 1.50 m (3 ft x 5 ft) outcroping of bedrock, 1.5 km (0.93 nm) bearing 258 T (238 M) from small cove on other side of Big Salt Lake, 224 m (735 ft) bearing 183 T (163 M) from SW end of isthmus to north, 25 m (82 ft) bearing 000 T (340 M) from benchmark 945 0623 A, 4 m (13 ft) from the treeline, and 1.00 m (3.28 ft) above the apparent high water line. BENCH MARK STAMPING: 0623 C 2008 DESIGNATION: 945 0623 C MONUMENTATION: Tidal Station disk VM#: 18698 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 55° 37.1' N ( 55.61906) LONGITUDE: 133° 1.7' W (-133.02808) The bench mark is a disk set flush in a rocky outcropping at waters edge 1.50 km (0.93 nm) bearing 260 T (240 M) from small cove on other side of Big Salt Lake, 180.0 m (590.4 ft) bearing 182 T (162 M) from SW end of isthmus to north, 50.00 m (164.00 ft) bearing 026 T (006 M) from benchmark 945 0623 B, 20.00 m (65.60 ft) east of treeline, and 0.85 m (2.79 ft) above high water.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9450623 PUBLICATION DATE: 07/31/2014 Name: BIG SALT LAKE, ALBENO BAY AK NOAA Chart: 17407 Latitude: 55° 36.0' N ( 55.60000) USGS Quad: PETERSBURG Longitude: 132° 57.0' W (-132.95000) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 0623 D 2008 DESIGNATION: 945 0623 D MONUMENTATION: Tidal Station disk VM#: 18699 AGENCY: IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 55° 37.2' N ( 55.61952) LONGITUDE: 133° 1.7' W (-133.02887) The bench mark is a disk set flush in a rocky outcropping 1.60 km (0.99 nm) bearing 262 T (242 M) from small cove on other side of Big Salt Lake, 130.0 m (426.4 ft) bearing 202 T (182 M) from SW end of isthmus to north, 75 m (246 ft) bearing 315 T (295 M) from benchmark 945 0623 C, 5 m (16 ft) east of treeline, and 1.05 m (3.44 ft) above the apparent high water line. BENCH MARK STAMPING: 0623 E 2008 DESIGNATION: 945 0623 E MONUMENTATION: Tidal Station disk VM#: 18700 AGENCY: IDB PID#: SETTING CLASSIFICATION: Rock OPUS PID: LATITUDE: 55° 37.2' N ( 55.61982) LONGITUDE: 133° 1.7' W (-133.02881) The bench mark is a disk set flush in a 1 m x 1 m (3 ft x 3 ft) rock 1.60 km (0.99 nm) bearing 263 T (243 M) from small cove on east side of Big Salt Lake, 100 m (328 ft) bearing 207 T (187 M) from SE end of isthmus to north, 35.00 m (114.8 ft) bearing 010 T (350 M) from benchmark 945 0623 D, and 25 m (82 ft) east of treeline and residing offshore at high water.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9450623 PUBLICATION DATE: 07/31/2014 Name: BIG SALT LAKE, ALBENO BAY AK NOAA Chart: 17407 Latitude: 55° 36.0' N ( 55.60000) USGS Quad: PETERSBURG Longitude: 132° 57.0' W (-132.95000) T I D A L D A T U M S Tidal datums at BIG SALT LAKE, ALBENO BAY based on: LENGTH OF SERIES: 30 DAYS TIME PERIOD: May 17, 2008 - June 15, 2008 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9451600 SITKA, BARONOF ISLAND, SITKA SOUND Elevations of tidal datums referred to Mean High Water (MHW), in METERS: MEAN HIGHER HIGH WATER MHHW = 0.220 MEAN HIGH WATER MHW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MHW 0623 A 2008 0.751 0623 B 2008 0.206 0623 C 2008 0.097 0623 D 2008 0.284 0623 E 2008 -0.244
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9450623 PUBLICATION DATE: 07/31/2014 Name: BIG SALT LAKE, ALBENO BAY AK NOAA Chart: 17407 Latitude: 55° 36.0' N ( 55.60000) USGS Quad: PETERSBURG Longitude: 132° 57.0' W (-132.95000) 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.