U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 4 Station ID: 9454818 PUBLICATION DATE: 04/20/2011 Name: BLUE FJORD, PORT NELLIE JUAN AK NOAA Chart: 16706 Latitude: 60° 29.5' N ( 60.49170) USGS Quad: SEWARD B-4 Longitude: 148° 14.5' W (-148.24200) T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: BLUE NO 1 MONUMENTATION: Survey disk VM#: 13839 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock cliff OPUS PID: LATITUDE: 60° 45.2' N ( 60.75330) LONGITUDE: 147° 57.5' W (-147.95800) The primary bench mark is a disk set in the south end of an overchnging rock cliff, on the east side of a peninsula running north and south on the east side of entrance to the fiord, 60 paces north of a prominent rock outcrop, and 0.61 m (2.0 ft) from the cliff which is about 91 m (300 ft) north of the south end of the peninsula. BENCH MARK STAMPING: BLUE NO 3 MONUMENTATION: Survey disk VM#: 13848 AGENCY: US Coast and Geodetic Survey (USC&GS) IDB PID#: SETTING CLASSIFICATION: Rock cliff OPUS PID: LATITUDE: 60° 45.2' N ( 60.75330) LONGITUDE: 147° 57.5' W (-147.95800) The bench mark is a disk set in the highest point of a lone prominent outcropping rock extending out from the south end of a large grassy area to the southward, in the same general area as bench mark BLUE NO 1 and BLUE NO 2.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 4 Station ID: 9454818 PUBLICATION DATE: 04/20/2011 Name: BLUE FJORD, PORT NELLIE JUAN AK NOAA Chart: 16706 Latitude: 60° 29.5' N ( 60.49170) USGS Quad: SEWARD B-4 Longitude: 148° 14.5' W (-148.24200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 4818 A 1997 MONUMENTATION: Tidal Station disk VM#: 13849 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock ledge OPUS PID: LATITUDE: 60° 45.2' N ( 60.75330) LONGITUDE: 147° 57.5' W (-147.95800) The bench mark is a disk set flush in rock, 70 m (230 ft) north of bench mark BLUE NO 3, which is set on a prominent rock ledge extending 20 m (66 ft) into the bay, approximately 30 (98 ft) north of a rock that is the high point of the area, at the base of the cliff at the beginning of the tree line, a large rotten tree 1 m (3 ft) to the north, and set approximately 8 m (26 ft) west of the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 4 Station ID: 9454818 PUBLICATION DATE: 04/20/2011 Name: BLUE FJORD, PORT NELLIE JUAN AK NOAA Chart: 16706 Latitude: 60° 29.5' N ( 60.49170) USGS Quad: SEWARD B-4 Longitude: 148° 14.5' W (-148.24200) T I D A L D A T U M S Tidal datums at BLUE FJORD, PORT NELLIE JUAN based on: LENGTH OF SERIES: 55 DAYS TIME PERIOD: September 5 1997 - October 29 1997 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9454240 VALDEZ, PRINCE WILLIAM SOUND Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 3.720 MEAN HIGH WATER MHW = 3.439 MEAN SEA LEVEL MSL = 1.997 MEAN TIDE LEVEL MTL = 1.956 MEAN LOW WATER MLW = 0.473 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW BLUE NO 1 3.061 -0.378 BLUE NO 3 3.126 -0.313 4818 A 1997 4.289 0.850
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 4 Station ID: 9454818 PUBLICATION DATE: 04/20/2011 Name: BLUE FJORD, PORT NELLIE JUAN AK NOAA Chart: 16706 Latitude: 60° 29.5' N ( 60.49170) USGS Quad: SEWARD B-4 Longitude: 148° 14.5' W (-148.24200) 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.