U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9455120 PUBLICATION DATE: 04/29/2004 Name: AGNES COVE AK NOAA Chart: 16682 Latitude: 59° 46.4' N ( 59.77330) USGS Quad: BLYING SOUND (D-7) Longitude: 149° 35.3' W (-149.58800) To reach the tidal bench marks from Seward, AK, navigate south through Ressurection Bay for 15.5 km (9.7 mi) to Caines Head, AK, then proceed 26 km (16 mi) SSW along the shoreline through Ressurection Bay to Agnes Cove, AK. The tidal bench marks are located along the beach in the rock outcrop extending SE portion of the Agnes Cove. The tide gauge was installed on the beach in the rock outcrop. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 5120 A 2001 DESIGNATION: 945 5120 A MONUMENTATION: Tidal Station disk VM#: 16582 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID#: BBFJ01 LATITUDE: 59° 46.4' N ( 59.77330) LONGITUDE: 149° 35.3' W (-149.58800) The bench mark is a disk set flush on a 1 m (3 ft) wide sloping granite ledge, 22.70 m (74.5 ft) WNW (300 degrees magnetic) from bench mark 5120 B 2001, and about 3 m (10 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: 9455120 PUBLICATION DATE: 04/29/2004 Name: AGNES COVE AK NOAA Chart: 16682 Latitude: 59° 46.4' N ( 59.77330) USGS Quad: BLYING SOUND (D-7) Longitude: 149° 35.3' W (-149.58800) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5120 B 2001 DESIGNATION: 945 5120 B MONUMENTATION: Tidal Station disk VM#: 16583 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID#: BBFJ08 LATITUDE: 59° 46.4' N ( 59.77330) LONGITUDE: 149° 35.3' W (-149.58800) The bench mark is a disk set flush on a horizontal granite outcropping, 22.70 m (74.5 ft) ESE (120 degrees magnetic) from bench mark 5120 A 2001, 14.81 m (48.6 ft) NNW (330 degrees magnetic) from bench mark 5120 C 2001, 3 m (10 ft) SW from the apparent high water line, and about 4 m (12 ft) above the apparent high water line. BENCH MARK STAMPING: 5120 C 2001 DESIGNATION: 945 5120 C MONUMENTATION: Tidal Station disk VM#: 16584 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 59° 46.4' N ( 59.77330) LONGITUDE: 149° 35.3' W (-149.58800) The bench mark is a disk set flush on a horizontal granite outcropping, 17.22 m (56.5 ft) NNW (340 degrees magnetic) from bench mark 5120 D 2001, 14.81 m (48.6 ft) SE (150 degrees magnetic) from bench mark 5120 B 2001, 14 m (46 ft) south from a prominent purple rock set in the hillside, 5 m (16 ft) SW from the high water line, 1 m (4 ft) SW of the edge of the rock ledge in which it is set, and about 2 m (8 ft) above the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9455120 PUBLICATION DATE: 04/29/2004 Name: AGNES COVE AK NOAA Chart: 16682 Latitude: 59° 46.4' N ( 59.77330) USGS Quad: BLYING SOUND (D-7) Longitude: 149° 35.3' W (-149.58800) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 5120 D 2001 DESIGNATION: 945 5120 D MONUMENTATION: Tidal Station disk VM#: 16585 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 59° 46.4' N ( 59.77330) LONGITUDE: 149° 35.3' W (-149.58800) The bench mark is a disk set flush on the highest point of a horizontal granite outcropping that slopes toward the water, located on the eastern most extent of the beach, 17.22 m (56.5 ft) SSE (160 degrees magnetic) from bench mark 5120 C 2001, 16.00 m (52.5 ft) north (000 degrees magnetic) from bench mark 5120 E 2001, 1 m (3 ft) east from the vegetation line, and about 3 m (9 ft) above the apparent high water line. BENCH MARK STAMPING: 5120 E 2001 DESIGNATION: 945 5120 E MONUMENTATION: Tidal Station disk VM#: 16586 AGENCY: National Ocean Service (NOS) IDB PID#: SETTING CLASSIFICATION: Rock outcrop OPUS PID: LATITUDE: 59° 46.4' N ( 59.77330) LONGITUDE: 149° 35.3' W (-149.58800) The bench mark is a disk set flush on a flat nook on a granite outcropping, 16.00 m (52.5 ft) south (180 degrees magnetic) from bench mark 5120 E 2001, 3 m (10 ft) SW from the high water line, 2 m (6 ft) east from the vegetation line, and about 2 m (8 ft) above the apparent high water line.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9455120 PUBLICATION DATE: 04/29/2004 Name: AGNES COVE AK NOAA Chart: 16682 Latitude: 59° 46.4' N ( 59.77330) USGS Quad: BLYING SOUND (D-7) Longitude: 149° 35.3' W (-149.58800) T I D A L D A T U M S Tidal datums at AGNES COVE based on: LENGTH OF SERIES: 2 MONTHS TIME PERIOD: August 2001 - September 2001 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9455090 SEWARD, RESURRECTION BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 3.257 MEAN HIGH WATER MHW = 2.976 MEAN SEA LEVEL MSL = 1.703 MEAN TIDE LEVEL MTL = 1.699 MEAN LOW WATER MLW = 0.421 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 5120 A 2001 6.850 3.874 5120 B 2001 6.023 3.046 5120 C 2001 5.581 2.604 5120 D 2001 6.029 3.053 5120 E 2001 4.363 1.386
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9455120 PUBLICATION DATE: 04/29/2004 Name: AGNES COVE AK NOAA Chart: 16682 Latitude: 59° 46.4' N ( 59.77330) USGS Quad: BLYING SOUND (D-7) Longitude: 149° 35.3' W (-149.58800) 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.