Pago Pago (Samoa) Site History

History Summary

Station Pago Pago, American Samoa
Country USA Trust
Latitude 14° 16.8' S
Longitude 170° 41.4' W
GLOSS No 144
Time Reference GMT (hours 00-23)
Contributor National Ocean Service (NOS) (1973+)
National Ocean. and Atmos. Administration (NOAA) US Coastal Geodetic Survey (1905-1972);
Instrument Type Standard mechanical (1948-1974)
Analog-to-digital (ADR) recorder (1975-1990)
Aquatrak acoustic gauge, NOAA Next Generation Water Level Measuring System (NGWLMS) (1991-2000)
Site of Gauge The gauges are situated near the oil dock, west of Goat Island Point.
Observational Periods 1948 - 2000

Please note that the position information has been altered in this document - see document 83916

Reference Level

All heights have been referred to the station tide staff zero which is linked to fixed benchmarks.

Tide Gauge Benchmark (TGBM) Description

Benchmark M 1983 the primary benchmark is stamped '0000 M 1983', and is set in a bedrock outcrop at the southern most corner of the wall surrounding the Government Estate.

Auxiliary Benchmarks

Eight additional benchmarks are levelled to the TGBM and the Tide Station on a yearly basis.

Benchmark Relationships

TGBM is 13.20 feet above the Tide Gauge Zero (Station Datum).

NOAA Chart Datum (MLLW) is 2.48 feet above the Station Datum.

Mean Sea Level (1960-1978) is 3.83 feet above the Station Datum.

Quality Assessment by the UH Sea Level Center

Comment

Reference level shifts were adjusted by adding the following to the original data:

Otherwise, the daily and monthly means in comparison with Apia suggest a level shift of about +12 cm on 1 August 1993 and of about -12 cm on 1 January 1995. This signal is under investigation by the originatiors.

The data for 1996-2000 were supplied with heights relative to MLLW. Consequently 759mm was added to refer the data to tide gauge zero.

The data for 1998-2000 were supplied in non-GMT format and had to be shifted into GMT.

Notable episodic events:

Gaps in the Data Record

The following gaps occur in the data set.

Year CI (%) Missing Data Replaced Gaps or Bad Data Questionable Fluctuations
1949 76 214-302 None None
1950 100 None None None
1951 92 337-365 None None
1952 99 1 (11)173-(10)174,(22)361-(11)362 None
1953 100 None (21)077-(11)078,(13)169-(23)169,(01)170-(11)170,(00)218-(14)218 None
1954 100 None None None
1955 100 None None None
1956 21 50-338 None None
1957 100 None None None
1958 100 None (04)192-(23)192 None
1959 100 None (01)210-(10)210 None
1960 100 None None None
1961 100 None None None
1962 91 224-258 (18)297-(12)298 302-303
1963 100 None (22)060-(21)061 None
1964 100 None None None
1965 100 None (20)305-(05)306 None
1966 100 None (20)152-(07)153,(15)291-(22)291 None
1967 100 None None None
1968 99 361-364 (12)002-(23)002,(10)003-(00)004,(15)270-(01)271 282,317-319
1969 100 None (03)338-(23)338 None
1970 100 None (00)206-(23)206 None
1971 100 None (15)053-(06)054 None
1973 100 None (15)265-(11)266 None
1974 100 None None 98,286
1975 89 275-305,348-351 None 29-33
1976 98 157-159,239-241 None 242-243
1977 100 None None None
1978 93 38-40,62-66,189-191,196-198,208-209,264-268,321-322,341-342,353-356 None 195
1979 96 21-22,23-24,30-31,38-44 None None
1980 97 97-100,306-309,314-315 None None
1981 68 121-152,205-288 (11)182-(04)183 None
1982 96 172-188 None 153-154
1983 100 None None None
1984 100 None None None
1985 100 153-156 None None
1986 100 None None None
1987 100 None None 351-359
1988 100 None None None
1989 100 None None None
1990 100 None None None
1991 100 None None None
1992 85 None None None
1993 100 None None None
1994 100 None None None
1995 100 None None None
1996 100 None None None
1997 100 None None None
1998 100 None None 30-34,43-64,78-96,100-136,164-170,191-200,223-337
1999 100 None None 31-41,53-68,357-365
2000 100 None None 245