QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 21 Jul 2000 Station : Antofagasta Latitude: 23 39.0S Country : Chile Longitude: 070 24.0W JASL # : 080A Time Meridian: 060W (GMT - 4 hr) GLOSS # : 174 Originator #:0265 NODC #: 52073001 Contributor : Servicio Hidrografico y Oceanografico de la Armada (SHOA) Casilla 324 Valparaiso CHILE Originator : same Original Data: analog Instrmnt Type: standard mechanical (01/1945 - 02/1987) Metercraft bubbler (03/1987+) Digitzd Intvl: one hour Present Data : Hourly, daily, and monthly values obtained by: Hourly : The original digitizing interval was hourly 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 : 06 Dec 1945 - 31 Dec 1999 Gaps > 1 mon : 1 May - 1 Jun 1967;1 Dec 1970 - 5 Apr 1971; 1 Sep 1977 - 3 Nov 1977;1 Oct - 31 Dec 1980; 1 Feb - 1 Mar 1982; 10 Nov - 16 Dec 1988 Time Refernce: GMT (hours 00-23) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 1945-1999 Refernce Levl: The originators have related the data to tide staff zero which is linked to a fixed set of bench marks. Specifically, BM #8 (established 1945) is used as a historical datum. However, original data as received from SHOA were adjusted with the SHOA station leveling data as follows. value added period( day/month/year ) to original(mm) ------------------------ --------------- *25/11/1973 - 03/01/1974 125 *24/01/1974 - 01/04/1974 100 01/01/1980 - 01/07/1981 730 *01/11/1982 - 12/11/1982 -110 *01/07/1983 - 18/07/1983 -120 *01/09/1983 - 02/09/1983 -120 *01/04/1985 - 03/04/1985 -080 *01/05/1985 - 06/05/1985 -080 05/03/1987 - 14/03/1987 190 *25/03/1987 - 12/06/1987 -1720 12/06/1987 - 31/12/1987 -1730 31/07/1995 - 14/04/1996 -430 *adjustment of shift in reference level deduced from the plot of hourly residuals and from comparison of daily values with Arica and Caldera. The uncertainty of these adjustments is a few cm. Data from 1988-1990 were received with the reference level tied to the BM #8 (1945) while data for other time periods were received without linking the data to BM #8. Thus, the following level adjustments have been applied to the original data based on SHOA geodetic level records: value added period( day/month/year ) to original(mm) ------------------------ --------------- 01/01/1980-31/12/1987 -780 01/01/1991-05/05/1995 -2515 05/05/1995-16/12/1997 -1913 16/12/1997-06/04/1999 -2015 06/04/1999-31/12/1999 -2712 Comment : The daily and monthy values agree reasonably well most of the time with neighboring stations, (Arica, Caldera, and Valparaiso). The mean level appears low during Aug - Oct 1973 while data between 29 Aug - 25 Oct 1990 appear about 12 cm high. Other suspicious level shifts appears to occur on 24 April,1993 (+10 cm), 14 Nov 1994 (+15 cm) and 01 Jan 1995 (-15 cm). The low frequency variations of 20-30 cm of 20-40 day duration during Jan - Apr 1994 and Nov 1994 - Mar 1995 do not match any of the neighboring sites and are suspect of erroneous reference level movements. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 1945 7 none (18)352-(10)353 none 1946 100 none (07)092-(17)092 none (02)229-(15)229 (19)328-(11)329 1947 100 none (07)066-(14)066 none (03)082-(13)082 (10)241-(18)241 (22)282-(06)283 (19)304-(23)304 1948 93 163-187 (00)159-(08)159 none 1949 92 152-182 (03)001-(11)001 none (22)137-(11)138 (09)247-(20)247 (00)265-(22)265 (20)267-(08)268 (19)268-(07)269 (19)353-(15)354 1950 100 none (22)009-(15)010 none (00)035-(22)035 (21)047-(15)048 (21)076-(15)077 (07)093-(15)093 (20)127-(11)128 (20)130-(11)131 (00)191-(11)191 (00)197-(07)197 (00)198-(18)198 (10)213-(23)213 (03)276-(11)276 (10)278-(22)278 (16)324-(11)325 (02)347-(20)347 (19)350-(07)351 1951 100 none (07)033-(19)033 none (19)036-(17)037 (21)084-(10)085 (00)086-(21)086 (08)119-(17)119 (14)152-(22)152 (01)244-(21)244 (08)255-(16)255 (03)315-(16)315 1952 100 none (12)077-(23)077 none (12)083-(23)083 1953 100 none (00)006-(22)006 none (01)091-(21)091 (05)150-(16)150 (14)156-(21)156 (14)222-(21)222 (18)272-(11)273 (17)315-(08)316 (00)318-(20)318 1954 100 none (18)186-(06)187 none (03)212-(23)212 (02)213-(10)213 (18)285-(11)286 1955 95 335-353 (04)256-(21)256 none (03)359-(22)359 1956 100 none (08)074-(23)074 none (20)079-(07)080 (06)091-(23)091 (19)157-(06)158 1957 100 none (00)048-(11)048 none (00)105-(11)105 (09)224-(20)224 (17)321-(05)322 1958 100 none (12)114-(23)114 none (19)119-(06)120 (00)218-(07)218 (00)252-(11)252 (00)295-(10)295 (18)314-(05)315 1959 99 66-68,88-91 none none 1960 97 141-153 (00)064-(11)064 none (12)115-(23)115 (00)139-(11)139 (16)328-(11)329 1961 100 none none none 1962 100 none (00)282-(11)282 none (15)282-(10)283 (08)327-(23)327 1963 100 none (01)015-(09)015 none (06)255-(18)255 1964 99 88-92 (22)001-(20)002 none (03)006-(15)006 1965 100 none (00)049-(11)049 none (12)050-(23)050 (08)259-(23)259 (12)267-(23)267 (06)306-(23)306 (17)321-(11)322 (00)351-(11)351 1966 98 90-91,112-117 none none 1967 91 121-152,228-229 (00)034-(11)034 none (00)153-(11)153 (15)182-(23)182 (00)208-(11)208 (00)210-(18)210 (18)221-(11)222 (12)341-(00)342 1968 94 289-294,349-366 (00)135-(11)135 none (00)139-(11)139 (00)182-(11)182 (15)203-(23)203 (02)315-(09)315 (00)337-(22)337 1969 99 1 none none 1970 92 335-365 (00)208-(22)208 none (00)209-(08)209 (17)214-(11)215 (06)239-(17)239 (12)244-(01)245 (02)291-(11)291 1971 74 1-95 (21)215-(04)216 none 1972 97 45-49,56-61,137- (12)022-(23)022 none 139,365-366 (08)039-(17)039 (08)040-(23)040 (04)114-(20)114 (16)141-(23)141 (00)230-(21)230 (00)331-(22)331 1973 97 1-4,85-91 (00)019-(20)019 none (20)071-(08)072 (08)127-(23)127 (12)139-(10)140 (00)302-(11)302 (09)347-(17)347 (08)361-(17)361 1974 99 363-365 (00)017-(19)017 362 (00)233-(17)233 (17)343-(08)344 (14)349-(10)350 1975 99 1 (22)171-(10)172 1-2 (06)175-(18)175 (07)241-(18)241 (18)267-(04)268 (12)334-(23)334 1976 100 none (00)038-(21)038 none 1977 82 1-3,228-229, (04)131-(03)132 none 244-307 (12)210-(23)210 (00)214-(11)214 (12)324-(23)324 1978 94 1-3,110-121,259-264, (13)036-(22)036 none 266-268,272-274 (20)121-(17)122 (00)141-(11)141 (04)146-(23)146 (01)213-(22)213 (15)275-(23)275 (12)295-(23)295 (21)348-(11)349 (16)351-(23)351 (17)362-(01)363 1979 98 47-50,52-54,305-307 (04)271-(03)272 1-2,46,59,116-120 (20)015-(03)016 (15)023-(13)024 (23)027-(11)028 (08)060-(03)061 (20)070-(11)071 (19)073-(11)074 (18)075-(11)076 (13)076-(23)076 (19)079-(08)080 (19)084-(08)085 (18)102-(08)103 (17)109-(11)110 (18)115-(11)116 (15)131-(05)132 (18)134-(09)135 (03)143-(23)143 (17)145-(04)146 (12)150-(05)151 (00)336-(19)336 1980 74 243-245,275-366 (00)010-(11)010 none (00)049-(09)049 (00)228-(10)228 1981 99 1 (06)215-(18)215 54-55,278-281 1982 92 32-61 (15)097-(04)098 none 1983 99 108-111 (04)026-(03)027 none 1984 98 75-76,114-116, (04)001-(11)001 80-83,92,101-102, 270-271 (21)060-(14)061 106-107,116-117,121- (17)079-(15)080 122,126,134-135,137- (04)133-(03)134 139 (15)186-(14)187 (04)261-(13)261 1985 99 326-327 (20)125-(12)126 none (04)145-(14)145 (02)210-(14)210 (15)244-(01)245 (07)329-(12)329 1986 98 121-125,286-287 (16)064-(13)065 16 (20)324-(13)325 1987 96 64,73-84 (04)001-(12)001 322-323 (06)039-(14)039 (14)182-(03)183 (14)342-(13)343 1988 87 55-56,58-60, (16)049-(15)050 47-48,270-272 74-79,281-283, (01)095-(18)095 315-351 (07)245-(05)246 (11)255-(18)255 (00)256-(11)256 (00)273-(09)273 (04)357-(12)357 1989 98 142-143,335-343 (05)025-(13)025 317-363 (21)041-(13)042 (00)052-(13)052 (00)070-(13)070 (23)115-(13)116 (14)121-(13)122 (06)123-(13)123 (14)155-(13)156 (15)199-(13)200 (08)248-(21)248 (15)272-(12)273 (04)296-(13)296 1990 95 30-41,145-148, (19)159-(11)160 115-116,148-149, 231-235,241-242, (21)162-(11)163 172,348 355-356 (12)184-(11)185 (18)187-(11)188 (17)188-(11)189 (05)204-(12)204 (15)206-(11)207 (15)244-(05)245 (01)257-(08)257 (21)347-(04)348 1991 98 125-127,170-171, (12)031-(23)031 28,48-49,57-58,88- 179-181 (22)055-(15)056 91,115-118 (16)060-(03)061 (08)087-(17)087 (15)129-(14)130 (16)208-(13)209 (16)345-(05)346 1992 97 35-37,88-90,351-357 (18)002-(14)003 328-329,359-360 (00)020-(13)020 (03)025-(13)025 (22)043-(14)044 (18)126-(13)127 (19)201-(13)202 (02)203-(13)203 (22)203-(05)204 1993 83 38-39,114-115,214- (04)004-(12)004 none 263,316-325,331-333 (16)013-(12)014 (05)042-(23)042 (20)334-(23)334 (01)335-(13)335 1994 94 20-26,28-38,79-83 (14)090-(23)090 none (04)206-(11)206 (23)360-(13)361 1995 99 66-69,76-78 (04)060-(11)060 none (06)073-(15)073 (07)086-(14)086 (19)120-(23)120 (19)122-(11)123 (19)141-(14)142 (21)228-(13)229 (23)241-(12)242 (22)276-(13)277 (18)279-(13)280 1996 99 82-84,138-140 (14)031-(23)031 none (20)070-(14)071 (21)086-(13)087 (20)104-(14)105 (01)159-(14)159 (22)221-(14)222 (02)260-(15)260 1997 97 49-52,83-88,90-91, (14)103-(03)104 none 95-96 (15)120-(23)120 (00)155-(13)155 (20)165-(15)166 (16)216-(14)217 (15)247-(13)248 (18)304-(23)304 1998 100 none (14)195-(13)196 none (07)265-(13)265 (16)318-(13)319 1999 56 1-160 (21)188-(11)189 none (19)204-(17)205 (13)246-(12)247