# Lake Naivasha, Kenya 1,650 Year Salinity and Lake Level Reconstructions #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/28632 # Description: NOAA Landing Page # Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/naivasha2019salinity.txt # Description: NOAA location of the template # # Original_Source_URL: # Description: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Climate Reconstructions # # Dataset DOI: # # Parameter_Keywords: lake level, salinity #-------------------- # Contribution_Date # Date: 2019-12-27 #-------------------- # File_Last_Modified_Date # Date: 2020-03-06 #-------------------- # Title # Study_Name: Lake Naivasha, Kenya 1,650 Year Salinity and Lake Level Reconstructions #-------------------- # Investigators # Investigators: Van der Meeren, T.; Ito, E.; Laird, K.R.; Cumming, B.F.; Verschuren, D. #-------------------- # Description_Notes_and_Keywords # Description: Chironomid-based salinity and lake level reconstructions for Lake Naivasha, Kenya for the past 1,650 years. # Data are from cores NC93.1-S and NC93.2-L, recovered during fieldwork in August 1993, from the Crescent Island Crater. # This data provides an update of the previously archived paleolimnological reconstruction from Verschuren et al. 2000 Nature, # available at https://www.ncdc.noaa.gov/paleo/study/6070. # This file updated 6 March 2020: small correction to age model to match final published version. #-------------------- # Publication # Authors: Thijs Van der Meeren, Emi Ito, Kathleen R. Laird, Brian F. Cumming, Dirk Verschuren # Published_Date_or_Year: 2019-11-01 # Published_Title: Ecohydrological evolution of Lake Naivasha (central Rift Valley, Kenya) during the past 1650 years, as recorded by ostracod assemblages and stable-isotope geochemistry # Journal_Name: Quaternary Science Reviews # Volume: 223 # Edition: 105906 # Issue: # Pages: # Report_Number: # DOI: 10.1016/j.quascirev.2019.105906 # Online_Resource: https://www.sciencedirect.com/science/article/pii/S0277379119303920 # Full_Citation: # Abstract: Lake Naivasha (central Rift Valley, Kenya) is regionally unique in having accumulated a continuous sediment record of climate-driven palaeohydrological change over the past 1650 years, attesting to dramatic shifts between freshwater high-stands and either fresh or saline low-stands. This study employs fossil ostracod assemblages and stable-isotope (d18O and d13C) signatures to disclose the lake's ecohydrological history and explain the evolving non-linearity between lake level and salinity. The original age model and lithology-based lake-level reconstruction are revised, and the diatom-inferred salinity reconstruction is expanded to the lower (pre-770 CE) part of the record. The stable-isotope time series showed limited coherence with the other proxies, probably due to complexities related to hydrological connections between different surface- and groundwater components shifting through time. Ostracod palaeoecological data indicate that between ca 350 and 1200 CE the system often veered towards hydrological closure, with frequent and high-amplitude shifts in lake level and salinity preventing long-term establishment of wetland vegetation. Low lake-level and saline conditions dominated between ca 900 and 1200 CE. After that time and particularly since the onset of more permanent Malewa River inflow ca 1430 CE, hydrologically open conditions prevailed. Salinity shifts exhibited lower amplitude and frequency, promoting the expansion of wetland vegetation and associated biota including benthivorous fish. With lake water balance strongly influenced by variation in river inflow, high-amplitude lake-level fluctuations continued throughout the freshwater phase of the past 600 years, notably creating a pronounced high-stand dated to ca 1600-1780 CE and the well-documented extreme low-stand of the early 1800s. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: NSF-DEB 93-20324, NSF-ATM 95-31222, NSF-RTG 90-14277 #------------------ # Funding_Agency # Funding_Agency_Name: Belgian Science Policy # Grant: BR/121/A2/PAMEXEA #------------------ # Site_Information # Site_Name: Lake Naivasha # Location: Africa>Eastern Africa>Kenya # Country: Kenya # Northernmost_Latitude: -0.765 # Southernmost_Latitude: -0.765 # Easternmost_Longitude: 36.41 # Westernmost_Longitude: 36.41 # Elevation: 1883 #------------------ # Data_Collection # Collection_Name: Naivasha2019salinity # Earliest_Year: 339 # Most_Recent_Year: 1994 # Time_Unit: Year CE # Core_Length: # Notes: #------------------ # Chronology_Information # Chronology: updated age model compared to Verschuren (2001) Journal of Paleolimnology 25, 297-311. # # Labcode sample identification used by 14C laboratory # depth_top Depth top of sample interval (cm) # depth_bottom Depth bottom of sample interval (cm) # mat.dated Material Dated # 14C.raw conventional radiocarbon age, years before 1950AD # 14C.raw_err radiocarbon age, standard error # datemeth Dating method # calib.14C_2sig_lo Calibrated age, 2-sigma lower confidence bound, year CE # calib.14C_2sig_up Calibrated age, 2-sigma upper confidence bound, year CE # calib_method Calibration method # rejected Rejected sample (yes/no) # notes Notes # # Labcode depth_top depth_bottom mat.dated 14C.raw 14C.raw_err datemeth calib.14C_2sig_lo calib.14C_2sig_up calib_method rejected # 150 178 Grass charcoal 120 50 14C AMS 1942 1671 IntCal13 no # 350 374 Acacia leaves, grass charcoal 320 40 14C AMS 1647 1471 IntCal14 no # 374 398 Grass charcoal 480 50 14C AMS 1615 1316 IntCal15 no # 419 420 Sedge rhizome 580 40 14C AMS 1420 1388 IntCal16 no # 486 506 Acacia leaves, grass charcoal 770 50 14C AMS 1294 1163 IntCal17 no # 506 510 Acacia twig 930 50 14C AMS 1208 1021 IntCal18 yes # 538 542 Charred wood 820 50 14C AMS 1280 1049 IntCal19 no # 542 546 Wood 1100 60 14C AMS 1023 776 IntCal20 yes # 558 562 Unburned grass stem 1250 50 14C AMS 883 669 IntCal21 yes # 562 566 Wood, bark, Acacia leaf 1030 50 14C AMS 1151 893 IntCal22 no # 562 566 Sedge rhizome 1040 50 14C AMS 1150 888 IntCal23 no # 592 602 Grass charcoal 1140 60 14C AMS 1016 728 IntCal24 no # 754 774 Sedge rhizome 1490 50 14C AMS 649 429 IntCal25 no # 806 822 Grass charcoal 1800 50 14C AMS 344 86 IntCal26 no # #---------------- # Variables # # Data variables follow are preceded by "##" in columns one and two. # Data line variables format: one per line, shortname-tab-variable components (what, material, error, units, seasonality, data type,detail, method, C or N for Character or Numeric data, free text) # ## depth_mm depth, , , mm, , , , ,N, ## age_CE age, , , year Common Era, , , , ,N, ## lake_level lake level, , , meter, ,climate reconstructions,,,N,water depth reconstruction at core site ## salinity salinity, , , uS/cm, ,climate reconstructions,,,N,diatom-based salinity reconstruction at core site # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: -999 # depth_mm age_CE lake_level salinity 0 1993 15.50 217 4 1992 15.00 216 8 1990 15.20 234 12 1987 14.60 276 16 1984 17.00 231 20 1979 17.30 219 24 1975 15.30 193 28 1971 16.70 192 32 1968 17.60 186 36 1965 17.30 165 40 1962 17.50 166 44 1960 15.10 213 48 1957 15.70 203 52 1954 14.6 225 56 1950 12.9 222 60 1947 13.5 219 64 1943 12.9 187 68 1939 14 282 72 1936 12.6 319 76 1932 14.9 261 80 1927 16.8 244 84 1923 19.5 232 88 1918 20.5 230 92 1914 21.5 259 96 1910 20.5 267 100 1905 20.7 417 104 1901 25.3 527 108 1896 26.2 334 112 1892 24.8 299 116 1888 17.7 253 120 1881 12.6 232 124 1873 12 208 128 1865 12 201 132 1857 14 222 136 1849 16 213 140 1841 16 238 144 1833 5 258 148 1828 5 242 152 1824 5.3 221 156 1820 6 240 160 1817 6.7 217 164 1813 8.8 155 168 1809 12.5 167 172 1805 16.1 160 176 1801 19.7 154 180 1798 23.4 174 184 1793 27 187 188 1789 22.3 182 192 1786 21.8 183 196 1782 25.3 190 200 1778 29.3 165 204 1772 33.8 149 208 1761 36 173 212 1748 36 168 216 1735 36 127 220 1723 36 124 224 1710 36 125 228 1697 36 123 232 1684 36 141 236 1671 36 162 240 1658 36 143 244 1646 36 140 248 1633 36 146 252 1620 33.8 141 256 1609 29.3 171 260 1603 26.4 182 264 1599 25.2 192 268 1595 24 251 272 1591 22.8 141 276 1587 21.6 201 280 1583 20.4 225 284 1579 19.2 195 288 1575 18 173 292 1571 16.8 183 296 1567 15.6 163 302 1561 13.8 211 304 1559 13.2 190 308 1555 12 212 312 1551 17 256 316 1547 17 251 320 1543 15.7 229 324 1539 13.1 230 328 1534 10.6 207 332 1529 8 679 336 1521 8 334 340 1502 8 982 344 1483 8 200 348 1474 8 235 352 1469 15.2 279 356 1465 22.4 685 360 1461 26 153 364 1457 26 155 368 1452 26 284 372 1448 26 150 376 1443 26 232 380 1438 26 221 384 1434 26 197 388 1429 26 187 392 1424 24.7 146 396 1419 22 195 400 1415 19.3 225 404 1410 16.7 233 408 1405 14 228 412 1401 11.3 483 416 1396 10 650 420 1392 10 813 424 1382 10 873 428 1361 10 916 432 1336 10 330 436 1314 10 373 440 1304 20 247 444 1299 20 249 448 1294 20 231 452 1288 20 221 456 1283 20 249 460 1278 20 316 464 1273 18.5 363 468 1268 15.5 267 472 1263 17 213 476 1258 20 178 480 1253 20 255 484 1248 20 238 488 1242 20 249 492 1238 14 851 496 1232 17 1409 500 1227 20 527 504 1222 8.7 3388 508 1212 3 16293 512 1194 3 15959 516 1168 3 2023 520 1141 3 3214 524 1115 3 2427 528 1089 3 344 532 1070 9.5 154 536 1060 16 327 540 1055 11.7 536 542 1052 7.3 6012 544 1049 3 23121 546 1043 3 23014 548 1035 3 14757 550 1028 3 13459 552 1012 3 10209 554 997 3 409 556 982 3 256 558 967 3 255 560 951 3 3034 562 936 3 2014 564 921 3 10375 566 905 3 1426 568 887 3 318 570 871 7.7 857 572 845 12.3 594 574 821 17 1503 576 808 17 2065 578 805 17 261 580 801 17 303 582 799 17 258 584 795 13.3 3112 586 792 9.7 1986 588 789 6 2472 590 785 6 4467 592 782 6 869 594 779 6 612 596 776 12.5 455 598 773 19 891 600 769 19 17783 602 765 5 12503 604 761 5 1019 606 757 5 3076 608 753 5 4467 610 749 5 4477 612 745 5.9 1816 614 741 7.8 3105 616 737 9.6 2123 618 733 11.5 5200 620 728 13.3 541 622 725 15.2 255 624 720 17 284 626 716 17 276 628 712 17 262 630 708 17 202 632 704 17 158 634 700 13.5 225 636 696 10 287 638 692 10 356 640 688 10 706 642 684 10 773 644 680 10 640 646 676 10 923 648 672 10 472 650 668 10 340 652 665 10 292 654 661 11.6 228 656 657 13.2 213 658 653 15.3 327 660 649 18 306 662 645 15 273 664 642 12 256 666 638 11.9 236 668 634 11.7 253 670 630 11.6 218 672 626 11.4 268 674 622 11.3 294 676 619 11.1 711 678 615 11 530 680 612 10.8 366 682 608 10.7 708 684 604 10.5 798 686 600 10.4 410 688 596 10.2 327 690 593 10.1 541 692 589 9.9 583 694 585 9.7 406 696 581 9.6 507 698 577 9.5 340 700 573 9.3 5495 702 570 9.2 855 704 566 9 326 706 562 13.5 264 708 558 18 275 710 554 18 1067 712 550 18 813 714 547 18 6776 716 543 11.5 15101 718 539 5 23121 720 535 5 20797 722 531 5 22646 724 528 5 23496 726 524 5 23227 728 520 5 22336 730 516 5 611 732 512 5 268 734 508 7.6 288 736 504 13.3 971 738 500 19 162 740 497 23 112 744 489 23 1618 746 485 23 1611 748 481 23 802 750 477 23 194 752 473 23 109 754 470 23 148 756 466 19 165 758 462 21 181 760 458 23 178 762 454 23 190 764 450 23 131 766 446 23 207 768 442 23 243 770 438 23 245 772 434 23 274 774 431 23 320 776 427 23 2168 778 423 24 213 780 418 25 162 782 415 25 146 784 411 25 136 786 407 25 160 788 403 25 155 790 399 25 120 792 395 25 114 794 391 25 120 796 387 25 137 798 383 25 190 800 380 25 144 802 375 21.3 531 804 372 17.7 354 806 367 14 269 808 363 10.3 346 810 359 6.7 439 812 355 3 466 814 351 -999 500 816 347 -999 356 818 343 -999 419 820 339 -999 4365