Lake Victoria Diatom Correspondence Analysis ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Lake Victoria Diatom Correspondence Analysis LAST UPDATE: 4/2003 (Original Receipt by WDC Paleo) CONTRIBUTORS: J. Curt Stager, Brian F. Cumming, L. David Meeker IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2003-025 SUGGESTED DATA CITATION: Stager, J.C., et al., 2003, Lake Victoria Diatom Correspondence Analysis, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2003-025. NOAA/NGDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL 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: 14,375 - 450 YrBP FUNDING SOURCE: National Science Foundation, Earth Systems History (USA). DESCRIPTION: Diatom series from Lake Victoria, Uganda, core Ibis -1, Damba Channel. Latitude 0° 05’0”N, Longitude 32° 48’2”E, 32 m water depth, lake surface elevation 1134 m. Correspondence analysis of the Ibis-1 diatom record produced two principal axes, CA1 and CA2 (Stager et al., 1997). CA1 reflects the relative abundances of diatom taxa representing well mixed conditions (Aulacoseira spp. and shallow-water taxa) and more stable/stratified water columns (Nitzschia spp.). CA2 responds to the proportions of shallow-water diatoms and appears to represent relative lake depth, thus serving as a rough proxy for precipitation/evaporation ratios. This interpretation is supported by the similarity of the CA2 curve to the percentages of moist forest pollen in Kendall's (1969) pollen record from Pilkington Bay core P-2. The chronology used here was obtained by subtraction of a 330 year ancient carbon correction factor from the bulk sediment dates prior to conversion to calendar years before 2000 AD (Stager et al., 2002). ABSTRACT: East Africa's enormous Lake Victoria dried out at the close of the last glacial, but the precise timing and origin of that drying event have not been clarified, largely because of uncertainty regarding core stratigraphy and ancient carbon effects on 14C dates from the lake. New dates and re-examination of evidence from widely distributed cores shows that desiccation occurred some time between 15900 and 14200 calendar years BP, and perhaps also ca. 18–17 kyr BP. These lake level minima were briefer than has been previously suggested and were synchronous with pronounced global climate disruptions including North Atlantic ice-rafting Heinrich event 1. Less severe declines occurred during the Older and Younger Dryas intervals. Dansgaard–Oeschger type cooling cycles registered in the GISP2 ice core record tracked major lake level regressions in East Africa and weakenings of Afro-Asian monsoons during the late Quaternary, possibly linking the desiccation of Lake Victoria to century-scale reductions in solar radiation output. DATA: Lake Victoria, Damba Channel, core Ibis-1 Chronology as presented in Stager et al. 2002. core depth (cm), calendar years before 2000 AD, Correspondence analysis principal axes CA1 and CA2. cm calyrBP caaxis1 caaxis2 0 457 104 -136 5 517 82 -133 10 577 98 -107 12.5 608 135 -141 15 638 174 -184 17.5 668 130 -173 20 698 164 -159 22.5 728 166 -168 25 758 207 -174 27.5 788 164 -137 30 818 175 -173 32.5 848 156 -167 35 879 210 -202 37.5 909 208 -170 40 939 173 -183 42.5 969 173 -173 45 999 158 -168 47.5 1029 193 -155 50 1059 173 -174 52.5 1089 123 -122 55 1119 141 -123 57.5 1149 101 -97 60 1180 107 -120 62.5 1210 108 -100 65 1240 74 -110 67.5 1270 94 -116 70 1300 66 -85 72.5 1330 78 -93 75 1360 89 -87 77.5 1390 86 -110 80 1420 94 -81 82.5 1451 78 -106 85 1481 74 -91 87.5 1511 50 -49 90 1541 60 -59 92.5 1571 35 -51 95 1601 7 -68 97.5 1631 -13 -73 100 1661 -7 -51 102.5 1691 -9 -57 105 1721 3 -76 107.5 1752 -18 -86 110 1782 2 -59 112.5 1812 -28 -96 115 1842 -13 -82 117.5 1872 -42 -129 120 1902 -20 -101 122.5 1932 -63 -126 125 1962 -63 -97 127.5 1992 -66 -110 130 2023 -49 -85 132.5 2053 -63 -111 135 2083 -38 -78 137.5 2113 -53 -101 140 2143 -35 -117 142.5 2173 -61 -96 145 2203 -35 -103 147.5 2233 -55 -131 150 2263 -51 -81 156 2336 -48 -52 158.5 2366 -82 -106 161 2396 -92 -116 163.5 2426 -109 -94 166 2456 -69 -108 168.5 2486 -95 -154 171 2516 -83 -130 173.5 2546 -64 -119 176 2577 -83 -106 178.5 2607 -91 -161 181 2637 -89 -115 183.5 2667 -103 -130 186 2697 -117 -78 188.5 2727 -104 -82 191 2757 -103 -65 193.5 2787 -82 -75 196 2817 -100 -67 198.5 2847 -121 -75 201 2878 -105 -92 203.5 2908 -143 -84 206 2938 -84 -62 208.5 2968 -98 -72 211 2998 -119 -70 213.5 3040 -127 -89 216 3081 -127 -51 218.5 3123 -141 -83 221 3165 -130 -84 223.5 3206 -128 -95 226 3248 -138 -87 228.5 3290 -97 -87 231 3331 -124 -53 233.5 3373 -119 -82 236 3415 -109 -65 238.5 3456 -134 -90 241 3498 -142 -94 243.5 3539 -123 -64 246 3581 -80 -41 248.5 3623 -102 -41 251 3664 -60 13 253.5 3706 -78 -8 256 3748 -67 3 258.5 3789 -69 -62 261 3831 -98 -65 263.5 3873 -82 -30 266 3914 -86 -27 268.5 3956 -81 -8 271 3998 -97 18 273.5 4039 -94 -15 276 4081 -112 -49 278.5 4123 -121 -41 281 4164 -126 -50 283.5 4206 -108 -1 286 4248 -83 -28 288.5 4289 -134 -83 291 4331 -120 -72 293.5 4372 -115 -59 296 4414 -115 -45 298.5 4456 -105 -14 301 4497 -124 -64 303.5 4539 -133 -59 306 4581 -83 -26 308.5 4622 -98 -29 311 4664 -96 -67 313.5 4706 -102 -15 316 4747 -104 -49 318.5 4789 -131 -55 321 4831 -93 -15 323.5 4872 -115 -35 326 4914 -135 -44 328.5 4956 -119 -39 331 4997 -133 -67 333.5 5039 -109 -21 336 5081 -134 -7 338.5 5122 -99 -2 341 5164 -65 10 343.5 5206 -79 -9 346 5247 -75 -36 348.5 5289 -84 -4 351 5330 -74 33 353.5 5372 -94 18 356 5414 -130 -39 358.5 5455 -120 -34 361 5497 -120 -25 363.5 5539 -76 -24 366 5580 -82 6 368.5 5622 -111 -4 371 5664 -92 46 373.5 5705 -114 19 376 5747 -103 42 378.5 5789 -99 2 381 5830 -93 4 383.5 5872 -101 10 386 5914 -123 -42 388.5 5955 -101 -10 391 5997 -86 -11 393.5 6039 -93 -10 396 6080 -93 7 398.5 6122 -73 -11 401 6164 -84 11 403.5 6205 -81 13 406 6247 -121 -29 408.5 6288 -120 -34 411 6330 -125 -54 413.5 6372 -118 -42 416 6413 -101 -23 418.5 6455 -118 -37 421 6497 -103 5 423.5 6538 -92 -7 426 6580 -107 -3 428.5 6622 -110 -12 431 6663 -100 -22 437 6763 -55 24 439.5 6805 -90 45 442 6847 -87 43 444.5 6888 -100 28 447 6930 -116 -4 449.5 6972 -109 15 452 7013 -100 33 454.5 7055 -72 61 457 7097 -111 42 459.5 7138 -99 66 462 7180 -79 60 464.5 7221 -72 69 467 7263 -81 72 469.5 7305 -82 82 472 7346 -57 72 474.5 7388 -54 37 477 7430 -69 20 479.5 7471 -41 61 482 7513 -55 52 484.5 7555 -81 20 487 7596 -74 28 489.5 7638 -98 44 492 7680 -94 75 494.5 7721 -65 86 497 7763 -73 47 499.5 7805 -90 10 502 7846 -41 62 504.5 7888 -38 55 507 7930 -45 104 509.5 7971 -48 76 512 8013 -62 63 514.5 8054 -45 112 517 8096 -60 81 519.5 8138 -6 134 522 8179 5 119 524.5 8221 26 144 527 8263 35 126 529.5 8304 36 169 532 8346 54 225 534.5 8388 50 231 537 8429 66 245 539.5 8471 59 234 542 8520 61 244 544.5 8569 54 228 547 8618 43 96 549.5 8667 38 129 552 8716 34 169 554.5 8765 43 189 557 8814 40 154 559.5 8863 69 136 562 8912 43 122 564.5 8960 54 162 567 9009 41 87 569.5 9058 62 164 572 9107 34 148 574.5 9156 54 152 577 9205 33 159 579.5 9254 33 127 582 9303 50 133 584.5 9352 33 82 587 9401 34 155 589.5 9450 46 157 592 9499 72 136 594.5 9548 64 133 597 9597 68 132 599.5 9646 63 136 602 9695 40 143 604.5 9744 49 78 607 9793 54 115 609.5 9842 57 154 612 9890 43 129 614.5 9939 41 136 617 9988 43 161 619.5 10037 43 142 622 10086 33 114 624.5 10135 52 141 627 10184 50 123 629.5 10233 51 119 632 10282 57 111 634.5 10331 18 144 637 10380 30 105 639.5 10429 42 127 642 10478 32 136 644.5 10527 44 117 647 10576 41 99 649.5 10625 16 142 652 10674 38 87 654.5 10723 44 112 657 10772 53 82 659.5 10820 41 111 662 10869 51 85 664.5 10918 56 148 667 10967 49 147 669.5 11016 57 125 672 11065 48 114 674.5 11114 58 149 677 11163 58 127 679.5 11212 26 101 682 11261 53 97 684.5 11310 38 103 687 11359 48 147 689.5 11408 57 163 692 11457 44 131 694.5 11506 62 156 697 11555 65 93 699.5 11604 88 136 702 11653 62 128 704.5 11701 47 109 707 11750 56 111 709.5 11799 49 100 712 11848 34 96 714.5 11897 36 96 717 11946 13 89 719.5 11995 31 79 725.5 12113 108 60 728 12162 87 6 730.5 12211 117 11 733 12259 104 19 735.5 12308 97 23 738 12357 137 -6 740.5 12406 156 -39 743 12455 130 3 745.5 12504 167 -35 748 12553 159 -40 750.5 12602 126 -11 753 12651 161 -49 755.5 12700 209 -118 758 12749 173 -52 760.5 12798 148 -35 763 12847 165 -64 765.5 12896 140 -20 768 12945 106 45 770.5 12994 116 10 773 13043 127 2 775.5 13092 110 23 778 13141 109 32 780.5 13189 92 59 783 13238 117 12 785.5 13287 114 19 788 13336 116 31 790.5 13385 84 46 793 13434 85 47 795.5 13483 135 -45 798 13532 166 -67 800.5 13581 183 -97 803 13630 200 -116 805.5 13692 210 -136 808 13754 208 -141 810.5 13816 257 -214 813 13878 285 -215 815.5 13940 258 -207 818 14003 168 -85 820.5 14065 122 -8 823 14127 120 0 825.5 14189 62 27 828 14251 50 24 830.5 14313 87 33 833 14375 45 122