Nauru Site History
|Country||Republic of Nauru|
|Latitude||00° 31.7' S|
|Longitude||166° 54.3' E|
|Time Reference||GMT (hours 00-23)|
|UH Sea Level Center
1000 Pope Road. MSB 317
|The National Tidal Facility (NTF),
Flinders University of South Australia GPO box 2100
|Instrument Type||1. (May 1974 - October 1985 )Fischer and Porter Analog-to-Digital Recorder (ADR)
2. (primary,Oct 1985-present) Leupold and Stevens Analog-to-Digital Recorder (ADR)
3. (backup,Feb 1984-present) Handar Encoder (ENC) (1993-1994 ENC primary)
4. NTF: Aquatrak acoustic gauge (SEAFRAME) (primary 4/Jan/1995 onward)
|Site of Gauge|
|Observational periods||1974 - 2001|
All heights have been referred to the station tide staff zero which is linked to fixed bench marks. The NTF series was tied to the existing series by adding 219 mm.
Tide Gauge Benchmark (TGBM) Description
|UH-1||The recessed triangle (steel pin is rusted away), has no stamp and is located two feet east of the tide well and one foot away from the edge of quay (established 01 May 1974).|
|UH-2B||0.5 inch hex head SS screw is set in epoxy with 'BM2B' written in the cement. It is located near crane warehouse wall below harbour masters office.|
|UH-3B||0.5 inch hex head bolt is set in epoxy with 'BM3B' written in the cement. It is located on the upper curb of Queen's Landing, 50 ft south of the habour masters house.|
|UH-6A||3/8 inch brass, located on left side of red door, it is the right hand pin of pair (UH-2B, UH-3B established August 1983, UH-6A - October 1989).|
Datum for levelling is zero of the tide staff established in 1988.
|UH-1 (Oct 1989)||-3.826m|
|UH-2B (Oct 1989)||-3.595m|
|UH-3B (Oct 1989)||-6.483m|
Even though the station at Nauru was installed in 1974, the initial benchmarks were not levelled until November 1976. Photos of benchmarks from the October 1989 levelling are available.
Quality Assessment by the UH Sea Level Center
The daily and monthly means reveal no apparent changes in the reference level and agree well with Kapingamarangi and Tarawa. The daily means and the hourly residuals show significant fluctuations with a period around a day associated with surges in the west- facing harbor in response to westerly winds.
The timing accuracy is no better than plus or minus 8 minutes prior to 1980.
Gaps filled with NTF data noted by * below.
|Year||CI(%)||Missing Data||Replaced Gaps or Bad Data||Questionable Fluctuations|
|1979||87||45-64,69-73,90-93,280-281,348-365||(13)303-(12)304 (04)337-(03)338||1-2,15,23-32,40-45,67-69,73-76,85-88, 158-159,162,164- 165,173,174,180,190-193,235-236,245,293-297,306-307,312,320,335,337-342,347-348|
|1994||100||215-216,250-251,301-308,344-349||*(00)215-(23)216 *(00)250-(23)251 *(00)301-(23)308 (00)309-(12)309 *(00)344-(23)349||none|