U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 PUBLICATION DATE: 08/22/2000 Station ID: 9451124 SUPERCEDED DATE: 04/21/2003 Name: STIKINE STRAIT ALASKA NOAA Chart: 17382 Latitude: 56° 21.2' N USGS Quad: Petersburg (B-2) Longitude: 132° 33.2' W To reach the tidal bench marks from Wrangell, transit SSW through Zimovia Strait, when abeam of Hat Island, proceed west through Chichagof Pass. The tidal bench marks and tide station were located on the west side of Drag Island. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 1124 B 2000 DESIGNATION: 945 1124 B MONUMENTATION: Tidal Station disk VM#: 16158 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Rock outcrop The primary bench mark is a disk set at the base of a rocky outcrop that extends from the tree line, located on the NW edge of the cobble beach on the west side of Drag Island. BENCH MARK STAMPING: 1124 A 2000 DESIGNATION: 945 1124 A MONUMENTATION: Tidal Station disk VM#: 16157 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Rock outcrop The bench mark is a disk set on top of a 7 m (23 ft) high rock outcrop on the south edge of the cobble beach located on the west side of Drag Island, and 6.0 m (19.7 ft) from the vegetation line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 PUBLICATION DATE: 08/22/2000 Station ID: 9451124 SUPERCEDED DATE: 04/21/2003 Name: STIKINE STRAIT ALASKA NOAA Chart: 17382 Latitude: 56° 21.2' N USGS Quad: Petersburg (B-2) Longitude: 132° 33.2' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 1124 C 2000 DESIGNATION: 945 1124 C MONUMENTATION: Tidal Station disk VM#: 16159 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Bedrock outcrop The bench mark is a disk set in a large bedrock outcrop located NW of the cobble beach on the west side of Drag Island, and 5.30 m (17.4 ft) NW of a high prominent rock ledge. BENCH MARK STAMPING: 1124 D 2000 DESIGNATION: 945 1124 D MONUMENTATION: Tidal Station disk VM#: 16160 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Bedrock outcrop The bench mark is a disk set in a small bedrock outcrop which is located between two larger rock outcrops that extend from the vegetation line, located on the north side of Drag Island. BENCH MARK STAMPING: 1124 E 2000 DESIGNATION: 945 1124 E MONUMENTATION: Tidal Station disk VM#: 16161 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Triangular granite boulder The bench mark is a disk set in a 1 m wide x 1 m high (4 ft x 2 ft) triangular granite boulder which stands alone on a beach face dominated by cleaved slate on the north side of Drag Island.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 PUBLICATION DATE: 08/22/2000 Station ID: 9451124 SUPERCEDED DATE: 04/21/2003 Name: STIKINE STRAIT ALASKA NOAA Chart: 17382 Latitude: 56° 21.2' N USGS Quad: Petersburg (B-2) Longitude: 132° 33.2' W T I D A L D A T U M S Tidal datums at STIKINE STRAIT based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: March 2000 - April 2000 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 9450460 KETCHIKAN, TONGASS NARROWS Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 4.849 MEAN HIGH WATER MHW = 4.583 MEAN TIDE LEVEL MTL = 2.520 MEAN SEA LEVEL MSL = 2.507 MEAN LOW WATER MLW = 0.456 MEAN LOWER LOW WATER MLLW = 0.000 Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 1124 B 2000 6.234 1.651 1124 A 2000 5.956 1.373 1124 C 2000 5.693 1.110 1124 D 2000 6.295 1.712 1124 E 2000 4.544 -0.039
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 PUBLICATION DATE: 08/22/2000 Station ID: 9451124 SUPERCEDED DATE: 04/21/2003 Name: STIKINE STRAIT ALASKA NOAA Chart: 17382 Latitude: 56° 21.2' N USGS Quad: Petersburg (B-2) Longitude: 132° 33.2' W 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 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.