Cocos Island (Keeling, Australia)Site History
History Summary
| Station | Cocos |
|---|---|
| Country | Australia |
| Latitude | 12° 07.0' S |
| Longitude | 096° 53.0' E |
| GLOSS No | 046 |
| Contributor | 1985-1988: TOGA Sea Level Center 1989-1998: National Tidal Facility, Flinders |
| Instrument Type | Float and stilling well gauge, Leupold and Stevens Analog-to-Digital Recorder 04/09/92-present NGWLMS (Acoustic gauge) |
| Site of Gauge | The gauge is situated along the concrete wall on the jetty opposite the grass verge, on Home Island. |
| Observational periods | 1985 - 2001 |
Reference Level
All data are referred to Tide Gauge Zero (TGZ) and linked into historic fixed benchmarks.
Tide Gauge Benchmark (TGBM) Description
| PSM 101 | The brass plaque is set in concrete at the base of the jetty on Home Island. |
|---|---|
| PSM 91 | The brass plug is in the concrete wharf (northern wall), Home Island. |
| Trig R379 | An RA Survey brass plaque is stamped R379, and is set in concrete at ground level, situated on the most SW point of Home Island, adjacent to the Clunies Ross Residence. |
Benchmark relationships
- TGZ = Local Chart Datum for both tide gauges.
- TGZ = 2.410 m below PMS 101.
- TGZ = 0.784m below Home Island Datum (approx. mean sea level).
Quality Assessment
Comment
The daily or monthly means do not reveal any obvious reference level shifts.
Since September 1992, atmospheric pressure has been measured at the tide gauge site. A daily signal has been observed in these data.
| Year | CI(%) | QI(%) | Missing Data | Replaced Gaps or Bad Data | Questionable Fluctuations |
|---|---|---|---|---|---|
| 1985 | 6 | 6 | none | none | none |
| 1986 | 100 | 99 | none | none | 45-52 |
| 1987 | 97 | 97 | 56-59,78-83,114-118,168-170 | (17)027-(06)028 (12)180-(09)181 | none |
| 1988 | 58 | 57 | 52-53 | none | none |
| 1989 | 90 | 90 | none | none | none |
| 1990 | 76 | 76 | 127-130,143-228 | none | none |
| 1991 | 92 | 92 | 305-337 | none | none |
| 1992 | 80 | 80 | 100-102,122-129,183-248 | none | none |
| 1993 | 100 | 100 | none | none | none |
| 1994 | 100 | 100 | none | none | none |
| 1995 | 99 | 99 | 74-75 | none | none |
| 1996 | 100 | 100 | none | none | none |
| 1997 | 100 | 100 | none | none | none |
| 1998 | 100 | 100 | none | none | none |
| 1999 | 99 | 100 | 50-52,53-55,59-60 | none | none |
| 2000 | 100 | 100 | none | none | none |
| 2001 | 100 | 100 | none | none | none |
