QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 05 Nov 2019 Station : Simon's Town Latitude: 34 11.0S Country : South Africa Longitude: 018 26.0E JASL # : 221A Time Meridian: 030E (GMT + 2 hr) GLOSS # : 268 Originator #: SB NODC #: 33014801 Contributor : South Africa Navy Hydrographic Office (SANHO) Private Bag X1 Tokai 7966 South Africa Originator : same Original Data: analog (float); digital (others) Instrmnt Type: Float and stilling well type: Kent (1958-1976), SIMPLEX (1977-1983), LEA (1983-1996) Acoustic SRD (1997-1/2003) Ott Kalesto radar gauge (1/2003-) Digitzd Intvl: hourly (float); 1 or 3 min (others) Present Data : Hourly, daily, and monthly values obtained by: Hourly : spot reading (float); average 9 min either side of the hour (others) Daily : 119-point convolution filter (Bloomfield, 1976) centered on noon applied to the hourly data with respective periods of the 95, 50, and 5% amplitude points at 124.0, 60.2, and 40.2 hours Monthly: Simple average of all daily values; calculated if 7 or fewer days are missing Span of data : 24 Apr 1959 - 31 Dec 2018 Gaps > 1 mon : 31 Dec 1964 - 31 Dec 1965;06 Mar 1979 - 04 Sep 1979 07 Jun 1985 - 30 Jul 1985;11 Oct 1988 - 10 Nov 1988 31 Mar 1989 - 04 Aug 1989;01 Jan 1990 - 07 May 1990 03 Aug 1994 - 03 Nov 1994;31 Dec 1995 - 22 Jul 1997 26 Dec 1997 - 05 Feb 2001;10 Jun 2002 - 31 Dec 2002 01 Nov 2004 - 08 Dec 2004;04 Jul 2011 - 11 Feb 2013 17 Nov 2014 - 09 Jan 2015;18 Nov 2016 - 31 Dec 2017 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : Yes Distribution : 1959-2018 Refernce Levl: All tidal heights are given above Chart Datum, which is the datum to which all soundings on the largest scale navigational chart of the area have been reduced. Chart datum is now Lowest Astronomical Tide (LAT) in all ports of the Republic of South Africa and Namibia. The relationship between LAT and Lands Leveling Datum (LLD), referred to as Mean Sea Level (MSL) by land surveyors, is given below. Tide Gauge Benchmarks: Trig Survey BM 28 G. UTM Grid Reference 34 HBT 641144. BM28D = 2.733m above MSL BM28F = 3.889m above MSL BM28G = 2.763m above MSL Benchmark relationships: Tide Gauge Zero (TGZ) = South Africa Chart Datum TGZ = 0.651m below LLD (MSL) until 31 Dec 1978 TGZ = 0.900m below LLD (MSL) from 01 Jan 1979 TGZ = 3.663m below BM 28 G TGZ was changed on 01 Jan 2003 onward as Mean Sea Level, which is the Land Leveling Datum. Comment : SANHO is the owner and copyright holder of the sea level data. Anyone downloading the information is to contact SANHO to request permission to use or reproduce the data. Permission can be requested via email to hydrosan@iafrica.com. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1959 69 none none 70 1960 100 none none none 1961 100 none none none 1962 100 none none none 1963 100 none none none 1964 100 none none none 1965 0 1-365 none none 1966 100 none none none 1967 100 none none 140-142,160-162 1968 100 none none none 1969 100 none none none 1970 100 none none none 1971 100 none (22)005-(21)006 none 1972 100 none none none 1973 100 none none 2-10 1974 99 229-233 none 329-339 1975 100 none none 320-329 1976 99 73-76,361-362 (07)004-(15)004 72-73 1977 100 none none none 1978 91 24-31,59-66, (14)230-(11)231 132-134,171-178, 90-94,101-108, (07)240-(14)240 274-365 136-142,231-233, 365 1979 45 1-19,65-247 (22)303-(21)304 none 1980 100 none none none 1981 100 none none 168-185 1982 99 337-342 none 150 1983 82 94-109,116-130, none none 158-186,201-202, 210-217 1984 94 91-93,101-108, (09)079-(22)079 79-136,209-213 136-144,288-290, (09)213-(21)213 292-297 1985 86 158-211 none 19,89-90,93,96,105- 115,119-127,138-158, 300,316-319,332-333 1986 97 57-62,132-139 none 171 1987 82 207-208,209-217, none 327-329,336-339 232-236,243-261, 264-268,279-285, 339-363 1988 59 13-18,23-25,33-41, (15)082-(07)083 47-49,64-66,78-82, 54-64,85-96,111-123, (13)104-(06)105 96-98,212-214 166-173,186-200,229- 235,247-274,275-278, 285-315,333-348 1989 62 90-216,221-235 (23)215-(10)216 none 1990 61 1-127,211-218,247- (10)131-(05)132 8-11,349-351 249,330-338,365 (08)132-(05)133 (16)142-(09)143 (19)356-(03)357 1991 87 1-4,56-59,78-92,161- none 46-50,104-106,128- 169,172-178,190-192, 135,182-190 344-357 1992 86 6-21,51-63,86-90, none 1-6 220-224,276-286, 300-304 1993 92 223-228,242-253,288- (13)343-(09)344 190,192,337,344-347 292,320-329 1994 57 70-75,160-182,199- (22)047-(07)048 14,122-123,188-195, 203,215-307,311-336, 203-205 357-365 1995 94 1-5,34-46,198-200, (14)027-(21)027 16-17,47-50,284, 302-303,352-355 (00)053-(07)053 357-358 (09)083-(21)083 (14)104-(21)104 (14)105-(22)105 (10)222-(09)223 (07)341-(15)341 (22)346-(09)347 1996 0 1-366 none none 1997 43 1-203,360-365 none none 1998 0 1-365 none none 1999 0 1-365 none none 2000 0 1-366 none none 2001 89 1-36,159-166 (14)177-(00)178 none (11)239-(03)240 (04)334-(13)334 (01)339-(15)339 (00)349-(07)349 (22)365-(20)001 2002 44 146-147,161-365 (22)090-(11)091 none (23)099-(07)100 (21)118-(04)119 (10)128-(04)129 (08)139-(17)139 (01)150-(11)150 (10)155-(21)155 2003 98 36-41,314-315 (04)084-(19)084 32-36 2004 86 204-205,211-217, (13)346-(01)347 199-211 306-343,357-365 (09)347-(20)347 (11)350-(20)350 (13)351-(20)351 (22)357-(21)358 2005 88 23-24,45-46,105-132, (12)004-(21)004 206-209,229-230, 234-236,325-335, (12)005-(11)006 260,274,306 364-365 (13)006-(00)007 (11)007-(20)007 (13)018-(21)018 (12)020-(20)020 (12)022-(00)023 (13)026-(20)026 (13)029-(20)029 (12)033-(21)033 (13)037-(03)038 (10)038-(20)038 (14)043-(21)043 (12)044-(22)044 (12)047-(22)047 (14)063-(21)063 (13)064-(02)065 (12)075-(23)075 (11)076-(23)076 (11)077-(23)077 (07)163-(22)163 (08)164-(05)165 (10)166-(17)166 (12)169-(21)169 (00)170-(09)170 (07)207-(15)207 (22)209-(05)210 (22)210-(21)211 (02)229-(10)229 (15)232-(00)233 (16)261-(01)262 (09)269-(16)269 (07)280-(14)280 (10)284-(17)284 (22)284-(15)285 2006 90 15-16,100-102,115- (14)184-(22)184 none 116,189-193,195-199, 201-202,229-248,263- 265,281-282 2007 93 50-53,57-72,226-234 (03)155-(11)155 none 2008 96 35-37,51-63,291-291 none none 2009 99 308-310,324-327 (20)288-(08)289 none 2010 99 148-153 (07)266-(22)266 none 2011 47 73-80,101-105,185- (05)117-(12)117 none 365 2012 0 1-365 none none 2013 86 1-42,107-114,254-255 (08)198-(07)199 none 2014 88 none none none 2015 96 1-9,57-62 (04)144-(13)144 none 2016 82 117-133,161-166, (08)243-(15)243 none 323-366 2017 0 1-365 none none 2018 98 73-75,138-141,229- (22)058-(21)059 none 231,335-337,365