GLOSS Station Handbook

GLOSS Station Handbook – Apra Hbr, Guam, Marianas

The GLOSS Station Handbook is currently being re-designed and upgraded.

Until a new version is available, the tide gauge station list below from the last version of the Handbook provides links to further details about each tide gauge in the GLOSS Core Network. Click the GLOSS number buttons to view the information. Click column headings to sort the table.


Station information

Gloss number149
Station nameApra Hbr, Guam, Marianas
Time zone150E, GMT + 10hrs
Latitude (+ve N)13.43333
Longitude (+ve E)144.65
Observation periods1948-
Responsible countryU.S.A.
Authority responsible for tide gaugeNOAA, National Ocean Service, 1305 East-West Highway, Silver Spring, MD 20910-3281, USA
GLOSS contactUSA
Committed to GLOSSYes
Location map
Digital dataYes
Aditional parametersAir temperature, barometric pressure, wind sensors
Data acquisition rateDigital gauge: 6 minute interval (after 1976)
Analog gauge: hourly heights (before 1976)
Fast delivery data at UHSLCData 053 File format
High frequency data at BODCData 149 Document 60035
High frequency data at UHSLCData 053a Document 053a File format
Data held at national organisationYes
Real-time data availableYes
Real-time data transmitted to GLOSS Fast Centre
Additional parameters (real-time)None
Tide gauge benchmarkBenchmark 4 (1949) is the primary benchmark (PBM) stamped 'NO 4 1949' set in the northwest side of a 6ft by 12ft concrete manhole in the centre of the road.
Benchmark relationshipsTGBM is 9.83ft above Tide Gauge Zero (Station Datum)
NOAA Chart Datum (MLLW) is 1.24ft above Station Datum
Mean Sea Level (1960-1978) is 2.65ft above Station Datum
Auxiliary benchmarks9 additional benchmarks are levelled to the TGBM and the Tide Station on a yearly basis.
BM's L, 5, and USN BM1 subsided during earthquake - October 1993 site inspection was primarily for levelling due to recent earthquake.
Other benchmarks include: BM 11, BM 4, BM 12, BM 13, BM 7 (P.I.E.), BM K, BM 6, BM 13
Data at PSMSL
Annual MSL (RLR) dataRLR 540
Annual MSL (RLR) plot
PSMSL code540
Other relevant codesUHSLC 053
Additional information
Last updated5 December 1993