Lake Tanganyika Late Holocene Diatom-inferred Conductivity Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Lake Tanganyika Late Holocene Diatom-inferred Conductivity Data LAST UPDATE: 9/2009 (Original receipt by WDC Paleo) CONTRIBUTOR: J. Curt Stager, Paul Smith's College IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2009-096 WDC PALEO CONTRIBUTION SERIES CITATION: Stager, J.C., et al. 2009. Lake Tanganyika Late Holocene Diatom-inferred Conductivity Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2009-096. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Stager, J.C., C. Cocquyt, R. Bonnefille, C. Weyhenmeyer, and N. Bowerman. 2009. A late Holocene paleoclimatic history of Lake Tanganyika, East Africa. Quaternary Research, Vol. 72, pp. 47-56. doi:10.1016/j.yqres.2009.04.003 ABSTRACT: A nearshore core (LT03-05) from the north basin of Lake Tanganyika provides diatom, pollen, and sedimentary time series covering the last ca. 3800 yr at 15-36 yr resolution. A chronology supported by 21 AMS dates on terrestrial and lacustrine materials allows us to account for ancient carbon effects on 14C ages and to propose refinements of the region's climatic history. Conditions drier than those of today were followed after ca. 3.30 ka by an overall wetting trend. Several century-scale climate variations were superimposed upon that trend, with exceptionally rainy conditions occurring 1.70–1.40 ka, 1.15–0.90 ka, 0.70–0.55 ka, and 0.35–0.20 ka. Around 0.55–0.35 ka, during the Spörer sunspot minimum, drier conditions developed in the northern Tanganyika basin while more humid conditions were registered at Lakes Victoria and Naivasha. This indicates significant variability in the nature and distribution of near-equatorial rainfall anomalies during much of the Little Ice Age. GEOGRAPHIC REGION: East Africa PERIOD OF RECORD: 3.8ka - present FUNDING SOURCES: US National Science Foundation (NSF) Earth Systems History grant (ATM-0401845) and Nyanza Project NSF grant (ATM-0223920). CC was supported by the Federal Science Policy, Belgium, Project EC/2 (CLIMLAKE: Climate variability as recorded in Lake Tanganyika). DESCRIPTION: Transfer function analysis of the LT03-05 diatom record produced a reconstruction of lake water conductivity that is believed to represent rainfall-driven dilution of the lake surface (lower conductivity = more rainfall/less evaporation/more river discharge into the lake). This interpretation is supported by the abundance of pollen from aquatic plants relative to those from terrestrial taxa, which shows a similar long-term rise (higher aquatic pollen = wetter climatic conditions). The aquatic plant pollen is believed to derive from the Luiche River watershed and delta; wetter climates should increase the extent of wetland vegetation and also increase its transport to the coring site in river discharge. The chronology was based on AMS dating of organic lake muds and terrestrial macrofossils. Ancient carbon correction factors for the radiocarbon ages of the sediments were obtained by comparison to the AMS ages of terrestrial samples in adjacent core intervals. Lake Tanganyika Core LT03-05: 4.95°S, 29.61°E, 773m elev., 130m. depth. DATA: 1. Lake Tanganyika Core LT03-05 Diatom-inferred Conductivity Column 1: Calendar years before 1950 AD, Column 2: Diatom-inferred conductivity (uS/cm) Column 3: Log conductivity Column 4: Error bars for Log conductivity CalYrBP Cond. LogCond. LogCond.Err. -18 180.80 2.2572 0.4346 -1 311.17 2.493 0.4224 16 365.17 2.5625 0.4233 33 397.37 2.5992 0.4247 50 399.85 2.6019 0.424 67 266.99 2.4265 0.4261 84 354.16 2.5492 0.4278 101 396.28 2.598 0.4236 118 443.00 2.6464 0.4296 135 303.95 2.4828 0.4247 153 334.58 2.5245 0.4225 170 409.83 2.6126 0.4267 187 367.96 2.5658 0.4221 204 199.34 2.2996 0.4246 221 245.08 2.3893 0.4258 238 235.23 2.3715 0.4234 255 266.13 2.4251 0.424 272 190.02 2.2788 0.4273 289 196.88 2.2942 0.4229 306 241.49 2.3829 0.4268 324 283.92 2.4532 0.4235 341 209.36 2.3209 0.4223 358 299.71 2.4767 0.4235 375 295.80 2.471 0.4209 392 302.76 2.4811 0.4213 409 389.22 2.5902 0.4248 424 346.58 2.5398 0.4236 439 317.61 2.5019 0.4231 455 385.92 2.5865 0.4232 470 335.04 2.5251 0.4209 485 352.05 2.5466 0.4269 500 376.79 2.5761 0.4268 516 368.98 2.567 0.4216 532 356.70 2.5523 0.4257 548 379.58 2.5793 0.4278 564 294.85 2.4696 0.4231 580 214.29 2.331 0.4225 596 268.97 2.4297 0.4228 612 260.32 2.4155 0.4242 628 268.23 2.4285 0.4203 644 175.39 2.244 0.4262 661 327.27 2.5149 0.425 677 277.20 2.4428 0.424 698 306.90 2.487 0.4244 718 284.58 2.4542 0.4231 739 294.92 2.4697 0.4258 760 330.98 2.5198 0.425 780 334.58 2.5245 0.4253 801 339.63 2.531 0.4247 821 420.82 2.6241 0.4256 842 301.02 2.4786 0.4209 865 365.26 2.5626 0.4264 888 247.29 2.3932 0.4215 912 192.84 2.2852 0.4288 935 263.94 2.4215 0.4225 958 265.77 2.4245 0.4221 981 219.23 2.3409 0.4213 1028 395.82 2.5975 0.4255 1051 352.37 2.547 0.4224 1074 205.21 2.3122 0.4266 1094 267.24 2.4269 0.4227 1114 185.65 2.2687 0.4316 1134 415.34 2.6184 0.426 1155 393.10 2.5945 0.4209 1175 462.38 2.665 0.4263 1195 462.38 2.665 0.4238 1215 436.62 2.6401 0.4263 1238 403.09 2.6054 0.4257 1260 429.73 2.6332 0.423 1283 419.37 2.6226 0.4238 1300 425.40 2.6288 0.4286 1316 481.28 2.6824 0.4275 1333 433.41 2.6369 0.4264 1350 451.96 2.6551 0.4213 1367 436.92 2.6404 0.4272 1383 404.11 2.6065 0.426 1400 343.16 2.5355 0.4229 1417 350.27 2.5444 0.4241 1433 409.92 2.6127 0.4264 1450 454.05 2.6571 0.4277 1468 328.78 2.5169 0.4205 1486 272.65 2.4356 0.4183 1504 358.01 2.5539 0.4214 1522 344.75 2.5375 0.4203 1540 372.13 2.5707 0.4242 1558 305.42 2.4849 0.418 1576 350.83 2.5451 0.4202 1594 344.43 2.5371 0.4202 1612 361.49 2.5581 0.4196 1630 361.33 2.5579 0.4219 1650 351.80 2.5463 0.4214 1669 430.82 2.6343 0.4249 1689 443.20 2.6466 0.4248 1709 436.92 2.6404 0.4264 1728 426.78 2.6302 0.4272 1748 456.04 2.659 0.425 1768 493.06 2.6929 0.4335 1787 533.46 2.7271 0.4279 1807 417.64 2.6208 0.4286 1830 470.76 2.6728 0.4251 1854 497.51 2.6968 0.4282 1877 448.23 2.6515 0.4302 1900 501.19 2.7 0.4347 1924 502.11 2.7008 0.441 1947 508.51 2.7063 0.4305 1970 554.75 2.7441 0.4328 1993 494.31 2.694 0.4286 2017 413.90 2.6169 0.4229 2040 539.26 2.7318 0.4286 2066 504.31 2.7027 0.4246 2084 499.11 2.6982 0.4271 2112 487.64 2.6881 0.4288 2139 513.69 2.7107 0.4251 2166 487.19 2.6877 0.4313 2193 530.88 2.725 0.4279 2220 508.86 2.7066 0.4294 2248 489.22 2.6895 0.4272 2275 535.80 2.729 0.4344 2302 526.38 2.7213 0.4294 2331 576.24 2.7606 0.4299 2360 549.03 2.7396 0.426 2390 541.75 2.7338 0.4242 2420 522.04 2.7177 0.4282 2450 507.46 2.7054 0.427 2480 530.64 2.7248 0.4263 2510 537.53 2.7304 0.4239 2540 526.02 2.721 0.423 2570 438.23 2.6417 0.4238 2600 439.95 2.6434 0.4226 2633 401.24 2.6034 0.4257 2666 463.66 2.6662 0.4249 2699 523.00 2.7185 0.4286 2732 493.63 2.6934 0.4263 2765 495.68 2.6952 0.4262 2798 526.14 2.7211 0.425 2831 520.00 2.716 0.4268 2864 562.08 2.7498 0.4311 2897 594.84 2.7744 0.4323 2930 589.66 2.7706 0.4402 2965 585.73 2.7677 0.4331 3000 605.20 2.7819 0.4316 3035 604.92 2.7817 0.43 3070 615.74 2.7894 0.433 3105 585.46 2.7675 0.4432 3140 636.80 2.804 0.4301 3175 583.04 2.7657 0.4195 3210 563.90 2.7512 0.4225 3245 589.25 2.7703 0.4247 3280 606.18 2.7826 0.4159 3316 557.31 2.7461 0.4152 3353 567.54 2.754 0.418 3389 612.91 2.7874 0.4184 3425 610.38 2.7856 0.4232 3462 598.69 2.7772 0.4223 3498 610.38 2.7856 0.4236 3534 653.88 2.8155 0.4166 3570 672.67 2.8278 0.4156 3607 663.59 2.8219 0.4153 3643 632.27 2.8009 0.415 3679 635.62 2.8032 0.4159 3716 681.71 2.8336 0.417 3752 679.99 2.8325 0.4158 2. Aquatic Pollen data Column 1: Pollen age (Calendar years before 1950 AD) Column 2: Percent aquatic pollen Age %Aquatic Pollen -18.4 26.2 15.8 17.5 84.2 23.6 118.0 18.0 152.6 31.7 187.0 27.0 221.0 19.0 255.1 15.0 289.0 21.0 323.5 33.7 358.0 23.0 392.0 15.0 424.0 27.0 455.0 20.0 484.8 19.2 516.0 22.2 548.0 21.6 580.0 21.3 612.0 15.7 644.0 22.2 677.0 26.5 718.3 29.1 842.0 22.2 934.8 25.5 981.2 25.0 1027.6 26.6 1074.0 24.6 1114.3 26.4 1154.6 18.0 1194.9 17.0 1283.0 18.6 1349.8 23.8 1416.6 28.0 1450.0 28.2 1486.0 25.9 1522.0 25.1 1558.0 24.4 1594.0 28.5 1612.0 17.9 1669.3 25.7 1708.7 20.8 1748.0 30.0 1787.3 21.5 1923.5 21.4 2016.7 25.9 2166.0 16.9 2331.0 20.4 2450.0 22.5 2570.0 19.8 2699.0 17.6 2765.0 9.7 2831.0 15.8 3035.0 18.3 3105.0 18.2 3175.0 15.4 3316.3 17.1 3534.1 12.9 3606.7 17.9