Zanzibar (Tanzania) Site History

History Summary

Station Zanzibar
Latitude 06° 09.3' S
Longitude 039° 11.4' E
Country Tanzania
GLOSS No. 297
Time Reference GMT (hours 00-23)
Contributor UH Sea Level Center in collaboration with
Commission of Lands and Environment,
Zanzibar
Instrument Type Float type, R.W. Munro, London, I.H. 109
Site of Gauge The tide gauge is situated at the seaward
end of the main jetty in Zanzibar harbour.
Observational Period 1984 - present

Reference Level

The sea level heights are referred to the zero point assigned to the tide staff.

Tide Gauge Benchmark (TGBM) Description

Old TGBM - about 30.0m from tide gauge (521209E, 9319992N)

Auxiliary Benchmarks

TGBM 1 is 3.709m above LSD
TGBM 2 is 3.750m above LSD
TGBM 3 is 3.925m above LSD

Benchmark Relationships

BM1 at Malindi roundabout = 3.80m above Land Survey Datum (1984, 1987)
Mean Sea Level is 2.08m above Chart Datum

Quality Assessment by the UH Sea Level Center

Comments

The daily and monthly means do not reveal any reference level shifts and agree fairly well with adjacent stations, Mombasa, Kenya and Dar Es Salaam, Tanzania.

Occasionally, timing errors were evident in the hourly data.

Year CI
(%)
Missing
Data
Replaced Gaps
or Bad Data
Questionable
Fluctuations
1984 84 None (02)363-(08)363 79,230,281-282
1985 99 67-68,192-193
(20)164-(08)165
20,47,66-67,96,98,
(05)294-(11)294
125-127,129,179
1986 100 None None 25-27,31,193
1987 100 None None 122-124,132-135,
180-181
1988 100 None None 105,158-160,
240-242
1989 100 None None 49-51,67-69,
82-84, 91-93,
314-316,349- 350
1990 95 208-226 None 96-100,140-150,
173- 175,227-230
282,309- 310,337-340
1991 100 None None 1-3,89-92,
153,164- 165
1992 100 None None None
1993 98 8-16 None None
1994 100 None None None
1995 100 None (13)184-(12)185 None
1996 100 None None None
1997 98 330-339 None None
1998 99 329-330 (21)203-(17)204 None