Pilkington Bay, Lake Victoria, Diatom Correspondence Analysis Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Pilkington Bay, Lake Victoria, Diatom Correspondence Analysis Data LAST UPDATE: 9/2003 (Original Receipt by WDC Paleo) CONTRIBUTORS: J. Curt Stager, Brian F. Cumming, L. David Meeker IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2003-062 SUGGESTED DATA CITATION: Stager, J.C., et al., 2003, Pilkington Bay, Lake Victoria, Diatom Correspondence Analysis Data, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2003-062. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCES: Stager, J.C., B.F. Cumming, & L.D. Meeker, 2003. A 10,000 year high-resolution diatom record from Pilkington Bay, Lake Victoria, East Africa. Quaternary Research 59: 172-181. ADDITIONAL REFERENCES: Stager, J.C., Mayewski, P.A., and Meeker, L.D., 2002. Cooling cycles, Heinrich event 1, and the desiccation of Lake Victoria. Palaeogeogr., Palaeoclim., Palaeoecol. 183: 169-178. Stager, J.C., B. Cumming, and L.D Meeker. 1997. An 11,400-year, high-resolution diatom record from Lake Victoria, East Africa. Quat. Res. 47: 81-89. Stager, J.C. 1984. The diatom record of Lake Victoria (East Africa): the last 17,000 years. In (D.G. Mann, ed.) Proceedings of the Seventh International Diatom Symposium, Philadelphia, 1982. Strauss & Cramer, Koenigstein. pp. 455-476 GEOGRAPHIC REGION: Lake Victoria, Uganda. PERIOD OF RECORD: 10,200 - 150 YrBP FUNDING SOURCES: National Science Foundation, Paul Smith's College (USA). DESCRIPTION: Diatom series from Pilkington Bay, Lake Victoria, Uganda. Latitude 0° 18’N, Longitude 33° 20'E, 11 m water depth, lake surface elevation 1135 m. Chronology is in calendar years before 2000 AD, based on radiocarbon dating of bulk sediments using a 330 year correction for ancient carbon contamination. Correspondence analysis axis 1(CAS1) reflects relative abundances of shallow and deep-water diatom taxa and thus approximates a gradient of precipitation:evaporation ratios (P:E) and/or lake depth. CAS2 reflects the relative abundances of diatom taxa that favor more or less stable stratification (Nitzschia spp. vs. Aulacoseira spp.) and thus approximates a gradient of water column stability. ABSTRACT: A new diatom record from Lake Victoria’s Pilkington Bay, subsampled at 21-25 year intervals and supported by 20 AMS dates, reveals a ca. 10,000 calendar year environmental history that is supported by published diatom and pollen data from two nearby sites. With their chronologies adjusted here to account for newly documented ancient carbon effects in the lake, these three records provide a coherent, finely resolved reconstruction of Holocene climate change in equatorial East Africa. After an insolation-induced rainfall maximum ca. 9000-8300 cal yr B.P., precipitation became more seasonal and decreased abruptly ca. 8200 and 5700 yr B.P. in apparent association with northern deglaciation events. Century-scale rainfall increases occurred ca. 8500, 7000, 5800, 4000 yr B.P. Conditions after 3000 yr B.P. were generally similar to those of today, but major droughts occurred ca. 1200-600 yr B.P. during Europe's Medieval Warm Period. DATA: Pilkington Bay, Lake Victoria core 64-2 diatom record Quat. Res. 59:172-181 (Stager et al., 2003) Correspondence analysis axes 1 & 2 Gaps in dataset represent breaks between rod core sections Age (calyrBP) CAST1 CAST2 147 145 105 180 221 157 220 182 97 230 193 84 250 193 133 270 187 133 290 146 161 320 196 79 355 197 147 380 213 184 415 194 152 440 216 138 480 142 91 575 173 85 595 202 112 610 177 91 660 174 112 667 204 64 695 141 82 710 176 101 715 153 82 725 171 78 727 138 70 735 174 67 743 154 51 756 155 69 770 176 62 783 178 69 797 151 39 1176 142 26 1197 138 -11 1218 122 8 1239 114 4 1260 145 12 1281 126 -10 1302 129 19 1323 102 20 1344 138 -2 1365 118 4 1386 117 51 1407 131 -31 1428 136 3 1449 144 -10 1470 136 8 1491 114 -16 1512 129 -24 1533 127 16 1554 113 -8 1575 119 -28 1596 79 -51 1617 124 -40 1638 110 7 1659 135 -28 1680 102 -38 1701 120 6 1722 108 -36 1743 117 -42 1764 119 -31 1785 118 17 1807 107 -31 1828 108 -27 1849 112 -29 1870 101 -10 1891 94 -3 1912 130 -24 1933 103 -21 1954 97 -10 1975 99 -57 1996 96 -47 2017 111 -27 2038 90 -38 2059 96 -27 93 -42 103 -50 102 -37 85 -36 108 -34 133 -22 98 -13 104 22 98 -5 126 -38 94 -61 99 -29 75 -52 2073 91 -66 2095 122 -42 2117 117 -37 2140 115 -44 2162 98 -70 2184 89 -64 2207 95 -45 2229 87 -68 2251 90 -62 2273 80 -58 2296 78 -17 2318 100 -53 2340 79 -68 2362 63 -84 2385 73 -86 2407 87 -58 2429 102 -67 2451 68 -109 2474 65 -66 2496 92 -67 2518 49 -66 2541 84 -83 2563 63 -76 2585 72 -65 2607 67 -82 2630 62 -100 2652 74 -71 2674 81 -67 2696 56 -106 2719 69 -80 2741 70 -91 2763 85 -75 2785 80 -75 2808 73 -85 2830 50 -81 3198 48 -107 3221 72 -60 3244 70 -95 3267 80 -48 3290 36 -115 3312 41 -102 3335 25 -120 3358 28 -116 3381 58 -105 3404 49 -99 3427 34 -149 3450 45 -95 3473 29 -111 3496 44 -114 3519 59 -126 3542 57 -123 3565 31 -103 3588 46 -107 3611 31 -117 3634 42 -102 3657 36 -137 3680 39 -109 3703 25 -143 3726 5 -90 3749 19 -121 3771 20 -92 3794 26 -127 3817 14 -99 3840 8 -133 3863 16 -86 3886 34 -115 3909 13 -127 3932 11 -73 3955 1 -126 3978 26 -97 4001 10 -110 4024 3 -89 4047 -7 -138 4070 -4 -155 4093 15 -151 4116 -35 -163 4139 -27 -141 4162 16 -157 4185 -11 -97 4208 -14 -98 4230 -50 -164 4615 -31 -165 4638 -42 -186 4662 -28 -136 4685 -11 -125 4709 -9 -137 4732 -34 -118 4756 -25 -98 4779 -34 -129 4803 -40 -138 4826 -44 -158 4850 -8 -125 4873 -27 -132 4897 -28 -157 4920 -42 -178 4944 -35 -186 4968 -46 -119 4991 -61 -134 5015 -39 -155 5038 -27 -155 5062 -77 -103 5085 -34 -157 5109 -54 -162 5132 -56 -141 5156 -57 -97 5179 -58 -105 5203 -23 -130 5226 -34 -51 5250 -46 -118 5273 -51 -123 5297 -57 -135 5320 -57 -104 5344 -25 -97 5367 -56 -97 5391 -55 -142 5414 -47 -106 5438 -67 -140 5461 -69 -104 5485 -72 -124 5508 -70 -101 5532 -64 -144 5555 -89 -138 5579 -83 -61 5602 -92 -118 5626 -84 -118 -69 -155 -86 -97 -70 -89 -46 -118 5630 -81 -78 5653 -87 -13 5677 -73 -50 5700 -93 -131 5724 -77 -49 5748 -100 -59 5771 -111 -71 5795 -90 -96 5818 -86 -59 5842 -131 -79 5866 -90 -131 5889 -84 -85 5913 -108 -73 5936 -90 -63 5960 -107 -97 5984 -80 -85 6007 -99 -75 6031 -106 -88 6054 -92 -46 6078 -81 -45 6102 -134 -24 6125 -122 -60 6149 -125 -57 6172 -105 -125 6196 -139 -59 6220 -115 -24 6243 -124 -14 6267 -96 -72 6290 -106 -18 6314 -139 -63 6338 -126 -63 6361 -130 -67 6385 -114 -42 6408 -120 -33 6432 -96 -38 6456 -126 -97 6479 -112 -75 6503 -103 -84 6526 -126 -68 6574 -59 -67 6597 -89 -39 6835 -67 -79 6860 -85 -31 6885 -63 -17 6909 -111 -44 6934 -91 -71 6958 -101 -1 6983 -94 20 7008 -74 40 7032 -76 -2 7057 -81 12 7082 -91 9 7106 -57 12 7131 -29 30 7156 -72 10 7180 -96 -25 7205 -82 15 7230 -69 -5 7254 -65 29 7279 -63 -9 7304 -96 -6 7328 -91 -52 7353 -109 32 7378 -86 67 7402 -116 43 7427 -99 33 7476 -120 1 7501 -95 77 7526 -86 5 7550 -112 -5 7575 -115 64 7600 -103 -7 7624 -109 9 7649 -96 -2 7674 -105 58 7698 -108 -30 7723 -113 40 7748 -96 34 7772 -68 44 7797 -94 -50 7822 -116 18 7846 -93 61 7871 -78 6 7895 -80 50 7920 -95 93 7945 -111 120 -132 115 -96 -59 -82 64 -66 -38 -74 11 -52 -25 -80 6 -115 -2 -78 24 -89 -21 -99 81 -80 55 -96 52 -117 -1 -114 24 -82 -19 -99 47 -97 -14 -115 61 -89 0 -89 46 -92 53 -129 123 -106 88 -98 61 -119 50 7962 -118 117 7987 -102 92 7992 -67 64 8017 -104 95 8042 -76 107 8067 -93 103 8092 -66 138 8117 -82 112 8142 -74 159 8167 -82 150 8192 -73 173 8218 -97 132 8243 -103 155 8268 -69 136 8293 -71 130 8318 -117 139 8343 -83 192 8368 -70 81 8393 -72 153 8419 -83 228 8444 -85 111 8469 -75 265 8494 -101 217 8519 -107 146 8544 -90 125 8569 -95 76 8594 -97 185 8620 -116 112 8645 -93 195 8670 -100 123 8695 -118 185 8720 -118 253 8745 -106 121 8770 -96 223 8795 -77 228 8846 -93 108 8871 -100 214 8946 -109 144 9044 -93 190 9145 -91 132 9246 -113 160 9346 -91 172 9397 -85 262 9447 -78 143 9498 -74 216 9548 -62 121 9598 -17 173 9649 -61 90 9699 -75 147 9800 -53 108 9901 -37 105 10002 -11 128 10102 13 127 10203 0 80