U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 PUBLICATION DATE: 10/23/2000 Station ID: 9452437 SUPERCEDED DATE: 04/21/2003 Name: EXCURSION INLET (SOUTH END) ALASKA NOAA Chart: 17316 Latitude: 58° 25.0' N USGS Quad: JUNEAU (B-5) Longitude: 135° 26.8' W To reach the tidal bench marks from Icy Passage, navigate 18 km (11 mi) east of Gustavus about 1/3 of the way up Excursion Inlet on the eastern shore near the main cannery building adjacent to the large pier. The bench marks are located in the vicinity of the pier along shore. The tide gauge was located just north of the main pier. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: EXCURSION INLET SO. END 5 1964 DESIGNATION: 945 2437 EXCURSION 5 MONUMENTATION: Tidal Station disk VM#: 15952 AGENCY: US Coast & Geodetic Survey (USC&GS) PID: SETTING CLASSIFICATION: Concrete step The primary bench mark is a disk set in the third of five concrete steps near the SW corner of a 30 m x 61 m x 1 m (100 ft x 200 ft x 4 ft) concrete fuel pen, 105 m (345 ft) NE of the east end of the cannery pier, and 10.21 m (33.5 ft) north of the SW corner of the foundation. BENCH MARK STAMPING: 2437 E 1999 DESIGNATION: 945 2437 E MONUMENTATION: Tidal Station disk VM#: 15953 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Loading dock The bench mark is a disk set in the northern corner of a concrete loading dock for the main building near the pier, 58 m (190 ft) south of bench mark 2437 F 1999, and 15 m (50 ft) NE of the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 PUBLICATION DATE: 10/23/2000 Station ID: 9452437 SUPERCEDED DATE: 04/21/2003 Name: EXCURSION INLET (SOUTH END) ALASKA NOAA Chart: 17316 Latitude: 58° 25.0' N USGS Quad: JUNEAU (B-5) Longitude: 135° 26.8' W T I D A L B E N C H M A R K S BENCH MARK STAMPING: 2437 F 1999 DESIGNATION: 945 2437 F MONUMENTATION: Tidal Station disk VM#: 15954 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Concrete foundation The bench mark is a disk set in the NW corner of the concrete foundation for a garbage pit, located outside of a chain link fence but inside an electric fence, and 140 m (460 ft) SW of bench mark 2437 G 1999. BENCH MARK STAMPING: 2437 G 1999 DESIGNATION: 945 2437 G MONUMENTATION: Tidal Station disk VM#: 15955 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Tar deck The bench mark is a disk set in the tar deck near the NW corner of a 30 m x 61 m x 1 m (100 ft x 200 ft x 4 ft) concrete fuel pen, just outside of the chain/barbwire fence near tank D1, and 47 m (155 ft) NW of bench mark EXCURSION INLET SO. END 5 1964. BENCH MARK STAMPING: 2437 H 1999 DESIGNATION: 945 2437 H MONUMENTATION: Tidal Station disk VM#: 15956 AGENCY: National Ocean Service (NOS) PID: SETTING CLASSIFICATION: Concrete deck The bench mark is a disk set in the concrete deck along the east side near the SW corner of a 30 m x 61 m x 1 m (100 ft x 200 ft x 4 ft) concrete fuel pen, directly across from a fence gate, and 43 m (140 ft) NE of bench mark EXCURSION INLET SO. END 5 1964.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 PUBLICATION DATE: 10/23/2000 Station ID: 9452437 SUPERCEDED DATE: 04/21/2003 Name: EXCURSION INLET (SOUTH END) ALASKA NOAA Chart: 17316 Latitude: 58° 25.0' N USGS Quad: JUNEAU (B-5) Longitude: 135° 26.8' W T I D A L D A T U M S Tidal datums at EXCURSION INLET (SOUTH END) based on: LENGTH OF SERIES: 62 hws and 62 lws TIME PERIOD: May 7,1999 - June 8,1999 TIDAL EPOCH: 1960-1978 CONTROL TIDE STATION: 9452210 JUNEAU, GASTINEAU CHANNEL, STEPHENS PASS Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 4.515 MEAN HIGH WATER MHW = 4.248 MEAN SEA LEVEL MSL = 2.365 MEAN TIDE LEVEL MTL = 2.357 MEAN LOW WATER MLW = 0.467 MEAN LOWER LOW WATER MLLW = 0.000 Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW EXCURSION INLET SO. END 5 1964 8.459 4.211 2437 E 1999 7.881 3.633 2437 F 1999 7.844 3.596 2437 G 1999 9.002 4.754 2437 H 1999 8.800 4.552
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 PUBLICATION DATE: 10/23/2000 Station ID: 9452437 SUPERCEDED DATE: 04/21/2003 Name: EXCURSION INLET (SOUTH END) ALASKA NOAA Chart: 17316 Latitude: 58° 25.0' N USGS Quad: JUNEAU (B-5) Longitude: 135° 26.8' W Foot Notes: Portions of SE Alaska in the area of Lynn Canal and Stephens Passage have anomalous relative sea level trends compared to most other geographic regions in the United States. This is due to a general uplift of the land in this area, which has been occurring at a rapid rate. Because of the magnitude of the sea level trends in these areas, NOAA has adopted a procedure for computing accepted tidal datums for the National Water Level Observation Network (NWLON) using the last several years of sea level data rather than the 19-year tidal epoch. The tide ranges are still based on the 1960 - 1978 National Tidal Datum Epoch (NTDE) and are applied to the five year (1994 - 1998) Mean Tide Level (MTL) to compute other tidal datums. The adoption of this procedure was necessary to ensure that tidal datums accurately represent the existing stand of sea level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 PUBLICATION DATE: 10/23/2000 Station ID: 9452437 SUPERCEDED DATE: 04/21/2003 Name: EXCURSION INLET (SOUTH END) ALASKA NOAA Chart: 17316 Latitude: 58° 25.0' N USGS Quad: JUNEAU (B-5) Longitude: 135° 26.8' 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.