Lake Tanganyika Deglacial Biogenic Silica and TOC Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Lake Tanganyika Deglacial Biogenic Silica and TOC Data LAST UPDATE: 2/2008 (Original receipt by WDC Paleo) CONTRIBUTORS: Jessica E. Tierney and James M. Russell, Brown University IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2008-022 SUGGESTED DATA CITATION: Tierney, J.E. and J.M. Russell. 2008. Lake Tanganyika Deglacial Biogenic Silica and TOC Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2008-022. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Tierney, J.E. and J.M. Russell. 2007. Abrupt climate change in southeast tropical Africa influenced by Indian monsoon variability and ITCZ migration. Geophys. Res. Lett., Vol. 34, L15709, doi:10.1029/2007GL029508. ABSTRACT: The timing and magnitude of abrupt climate change in tropical Africa during the last glacial termination remains poorly understood. High-resolution paleolimnological data from Lake Tanganyika, Southeast Africa show that wind-driven seasonal mixing in the lake was reduced during the Younger Dryas, Inter-Allerød Cool Period, Older Dryas, and Heinrich Event 1, suggesting a weakened southwest Indian monsoon and a more southerly position of the Inter-Tropical Convergence Zone over Africa during these intervals. These events in Lake Tanganyika, coeval with millennial and centennial-scale climate shifts in the high latitudes, suggest that changes in ITCZ location and Indian monsoon strength are important components of abrupt global climate change and that their effects are felt south of the equator in Africa. However, we observe additional events in Lake Tanganyika of equal magnitude that are not correlated with high-latitude changes, indicating the potential for abrupt climate change to originate from within tropical systems. ADDITIONAL REFERENCES: Cohen, A.S., K.E. Lezzar, J. Cole, D. Dettman, G.S. Ellis, M.E. Gonneea, P.D. Plisnier, V. Langenberg, M. Blaauw, and D. Zilifi. 2006. Late Holocene linkages between decade-century scale climate variability and productivity at Lake Tanganyika, Africa. J. Paleolim., 36, 189-209. Felton, A., J.M. Russell, A. S. Cohen, M. E. Baker, J. Chesley, M. McGlue, K. E. Lezzar, J. Pigati, J. Quade, and J. C. Stager. 2007. Geochemical and sedimentological records of late Quaternary climate change, Lake Tanganyika, tropical Africa. Palaeogeogr. Palaeoclimatol. Palaeoecol., in press. Stuiver, M., and P.J. Reimer. 1993. Extended 14C Data Base and Revised CALIB 3.0 14CAge Calibration Program. Radiocarbon, 35, 215-230. GEOGRAPHIC REGION: Southeast Africa PERIOD OF RECORD: 18 KyrBP - 10 KYrBP FUNDING SOURCES: US National Science Foundation (The Nyanza Project, ATM 0223920 and BIO 0383765), and US Dept. of Defense NDSEG Fellowship program (J.T.) DESCRIPTION: This dataset includes biogenic silica and total organic carbon as measured on core NP04-KH3 from Lake Tanganyika, spanning the time interval coincident with the last deglaciation. Chronology for the core was established by C14-AMS dating. Core NP04-KH3, Kalya Horst, Lake Tanganyika: 6º42.827'S, 29º49.957'E, 773m elev, 644m depth. DATA: 1. Radiocarbon ages Calibrated radiocarbon dates used to construct the age model for core KH3. Paired bulk organic and terrestrial macrofossil 14C dates published here (reservoir values indicated in bold in the table) and by Cohen et al. [2006] suggest that Lake Tanganyika's radiocarbon reservoir has increased during the Holocene. Our estimated 14C reservoir corrections are zero prior to ~13,300 14C yr, and appear to increase linearly to 458 14C years through the Holocene (see Felton et al. [2007] for a more complete discussion of the radiocarbon reservoir.) Uncertainty associated with reservoir estimates (based on the laboratory errors on paired dates) is incorporated into the final calibrated 2-sigma error ranges; thus, in many cases the 2-sigma ranges reported are wider than the output from the calibration software. Calib 5.0.1 was used to calibrate all dates listed [Stuiver and Reimer, 1993]. Column 1: Lab accession number Column 2: Depth (cm) Column 3: Material Column 4: 14C Age, radiocarbon years, as reported by the analysis facility Column 5: 14C error, radiocarbon years, 1-sigma error associated with the radiocarbon analysis Column 6: 14C reservoir correction, radiocarbon years, based on an assumed linear drift in the lake reservoir Column 7: Calibrated Age, years before present, obtained using the software Calib 5.0.1. Column 8: 2s error range, years before present, 2-sigma error ranges of the dates given reservoir uncertainties, calibration uncertainties, and laboratory error. Lab Accession # Depth Material 14Cage 14Cerr ResCorr ReservCorr CalibAge 2s err.range WHOI-NOSAMS-50145 72.5 Bulk sediment 4380 40 410 3970 4434 4338-4579 AA61732 174 wood 7838 51 n/a n/a 8602 8509-8779 AA61733 174 Bulk sediment 8135 51 297 7838 8602 8509-8779 AA64614 210 Bulk sediment 9113 60 227 8886 9970 9760-10307 AA67019 232 Bulk sediment 9547 59 203 9344 10642 10372-10908 AA64615 252 Bulk sediment 10268 62 164 10104 11579 11338-12020 AA67020 282 Bulk sediment 10617 58 144 10473 12463 12104-12690 AA67021 312 Bulk sediment 12174 84 59 12115 13903 13742-14089 AA61729 332 wood 13250 69 n/a n/a 15495 15333-16109 AA61728 332 Bulk sediment 13320 71 0 n/a 15600 15421-16218 WHOI-NOSAMS-50146 362 Bulk sediment 14650 70 0 n/a 17619 17184-17991 AA68364 382 Bulk sediment 15890 84 0 n/a 19100 18920-19300 2. Core NP04-KH3 data Column 1: Core Depth (cm) Column 2: Age (yr BP) Column 3: Biogenic Silica Column 4: Total Organic Carbon Depth Age Bsi TOC 222 10360 11.11 8.6 223 10395 8.89 9.14 224 10431 17.96 8.05 225 10466 21.26 7.42 226 10502 23.04 6.63 227 10537 16.08 7.8 228 10573 20.91 7.39 229 10610 40.64 5.67 230 10646 35.13 7.34 231 10683 18.89 10.28 232 10720 21.93 9.26 233 10758 20.77 8.8 234 10796 20.93 8.66 235 10834 14.81 9.29 236 10872 8.63 8.72 237 10911 11.95 9.17 238 10950 16.39 8.92 239 10990 15.23 9.41 240 11029 23.73 8.66 241 11069 33.54 6.41 242 11108 37.07 6.32 243 11148 39.5 6.57 244 11187 31.69 6.88 245 11227 28.93 7.53 246 11266 38.02 6.12 247 11305 34.42 6.37 248 11343 14.7 8.63 249 11381 20.78 8.95 250 11419 36.72 6.91 251 11457 36.69 6.22 252 11493 28.56 7.04 253 11530 20.47 9.15 254 11566 22.11 8.94 255 11602 32.02 7.1 256 11637 32.59 7.24 257 11673 23.49 8.76 258 11707 9.16 9.59 259 11742 10.68 9.84 260 11776 9.96 11.83 261 11811 5.76 11.42 262 11845 6.33 14.16 263 11879 5.58 16.14 264 11913 9.77 13.86 265 11946 11.5 14.87 266 11980 11.8 15.22 267 12014 12.75 15.15 268 12048 11.6 14.94 269 12082 9.45 16.24 270 12116 9.11 14.64 271 12150 7.97 14.88 272 12184 7.9 15.09 273 12219 8.1 14.84 274 12253 12.65 14.93 275 12288 10.82 13.84 276 12324 8.89 13.84 277 12360 13.63 14.11 278 12396 19.68 12.99 279 12432 17.77 14.5 280 12469 21.58 12.04 281 12507 13.42 12.83 282 12545 12.03 12.27 283 12584 14.98 11.43 284 12624 16.3 11.02 285 12664 20.74 10.47 286 12705 24.69 10.18 287 12746 21.41 10.53 288 12788 29.31 10.16 289 12832 33.34 9.03 290 12875 25.64 10.57 291 12920 14.56 13.14 292 12965 11.67 14.19 293 13012 12.09 13.76 294 13059 13.03 13.67 295 13107 12.62 12.45 296 13156 12.3 12.22 297 13205 15.13 11.34 298 13256 17.43 11.05 299 13307 23.32 10.68 300 13359 22.64 10.45 301 13413 24.55 9.75 302 13467 14.38 12 303 13522 13.78 10.92 304 13577 13.49 11.04 305 13634 16.97 10.17 306 13692 37.57 6.33 307 13750 35.84 6.31 308 13810 17.71 10.15 309 13870 17.6 10.74 310 13931 27.92 8.02 311 13993 15.5 9 312 14057 9.88 12.34 313 14121 7.25 12.75 314 14186 5.72 11.53 315 14253 8.86 13.49 316 14320 25.19 10.27 317 14389 30.1 9.01 318 14458 39.5 5.84 319 14527 20.04 9.97 320 14597 39.81 7.1 321 14668 38.14 7.76 322 14739 40.71 7.14 323 14811 26.71 8.9 324 14883 23.48 8.68 325 14955 25.54 8.18 326 15027 11.51 9.57 327 15100 18.63 9.37 328 15172 8.42 8.4 329 15245 6.83 9.52 330 15318 7.93 12.92 331 15390 16.32 11.4 332 15463 9.99 12.9 333 15536 15.99 10.37 334 15608 17.08 10.79 335 15681 20.69 9 336 15754 18.32 11.13 337 15826 10.58 13.45 338 15899 15.67 11.52 339 15971 14.3 11.99 340 16043 10.57 11.59 341 16116 9.93 11.98 342 16188 12.35 12.01 343 16260 15.04 11.66 344 16333 10.77 11.54 345 16405 9.44 10.83 346 16477 11.63 10.17 347 16550 23.45 7.54 348 16623 41.47 6.41 349 16695 27.6 6.15 350 16768 17.63 5.4 351 16840 15.11 5.08 352 16913 19.69 6.12 353 16985 25.84 7.24 354 17057 38.28 5.76 355 17128 39.37 6 356 17200 36.56 6.33 357 17271 31.77 7.57 358 17343 36.71 7.02 359 17414 36.99 6.64 360 17485 38.83 4.94 361 17557 32 5.63 362 17628 30.2 5.73 363 17700 29.51 5.65 364 17772 25.88 5.28 365 17844 20.5 5.25 366 17916 20.95 5.24 367 17989 19.54 5.01 368 18061 21.7 4.39 369 18134 22.62 4.32 370 18208 23.27 4.18 371 18281 23.58 4.07 371.75 18355 24.35 4.52