GLOSS Station Handbook

Station information sheet

GLOSS number149
Station name

Apra Hbr, Guam, Marianas

Time zone150E, GMT + 10hrs
Latitude (+ve N)13.43333
Longitude (+ve E)144.65
Observation period(s)1948-
Responsible countryU.S.A.
Authority responsible
for tide gauge
NOAA, National Ocean Service, 1305 East-West Highway, Silver Spring, MD 20910-3281, USA
GLOSS contactUSA
Committed to GLOSSYes
Location mapView location map for GLOSS station Apra Hbr, Guam, Marianas
Digital dataYes
Additional 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 UHSLCDownload h053.dat from UHSLC   Format documentation for UHSLC data
High frequency data at BODCDownload from BODC   View Apra Hbr, Guam, Marianas site history  
High frequency data at UHSLCDownload from UHSLC   Download documentation qa053a.dmt from UHSLC   Format documentation for UHSLC data
Data held at national organisationYes
Real-time data availableYes
Real-time data transmitted
to GLOSS Fast Centre
Real-time data plots from UHSLC
Additional parameters (real-time)Air temperature, barometric pressure, wind sensors
Tide gauge benchmarksBenchmark 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) dataDownload annual MSL (RLR) data for Apra Hbr, Guam, Marianas
Annual MSL (RLR) plotView annual MSL (RLR) plot for Apra Hbr, Guam, Marianas
PSMSL code540
Other relevant codesUHSLC 053
Additional information 
Last updated1993-12-05