Lithostratigraphic analyses of the sedimentary record from two contrasting crater lake basins in western Uganda, Africa, provide evidence for three major century-scale arid intervals during the last 2000 years. Variations in sedimentation and salt mineralogy of hypersaline Lake Kitagata, and a succession of fine-grained lake sediments and peat in the freshwater Lake Kibengo, suggest century-scale droughts centred on AD 0, ~1100, ~1550 and 1750. These results broadly support data from nearby Lake Edward on the timing of drought in western Uganda, but contrast with lake sediment records from eastern equatorial Africa. In particular, our results suggest regional variability of East African climate during the main phase of the ‘Little Ice Age’ (AD ~1500 to 1800), with westernmost East Africa experiencing drought while areas farther east were wet. This spatial pattern highlights the strongly regional nature of century-scale climate changes over the African continent, and holds implications for the mechanisms governing African rainfall during the ‘Little Ice Age’.
Alin, S. R. and Cohen, A. S.2003: Lake-level history of Lake Tanganyika, East Africa, for the past 2500 years based on ostracode-inferred water-depth reconstruction. Palaeogeography, Palaeoclimatology, Palaeoecology199, 31-49.
2.
Appleby, P. G. and Oldfield, F.1978: The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210Pb to the sediments. Cantena5, 1-8.
3.
Appleby, P. G., Nolan, P. J., Gifford, D. W., Godfrey, M. J., Oldfield, F., Anderson, N. J. and Battarbee, R. W.1986: 210Pb dating by low background gamma counting. Hydrobiologia141, 21-27.
4.
Appleby, P. G., Richardson, N. and Nolan, P. J.1992: Self-absorption corrections for well-type germanium detectors. Nuclear Instrumentation and Methods B71, 228-233.
5.
Arad, A. and Morton, W. H.1969: Mineral springs and saline lakes of the western rift valley, Uganda. Geochimica et Cosmochimica Acta33, 1169-1181.
6.
Ashok, K., Guan, Z. and Yamagata, T.2001: Impact of the Indian Ocean dipole on the relationship between the Indian monsoon rainfall and ENSO. Geophysical Research Letters28, 4499-4502.
7.
Ashok, K., Chan, W. L., Motoi, T. and Yamagata, T.2004: Decadal variability of the Indian Ocean dipole. Geophysical Research Letters31, L24207-L24207.
8.
Barker, P. and Gasse, F.2003: New evidence for a reduced water balance in East Africa during the Last Glacial Maximum: implication for model-data comparison. Quaternary Science Reviews22, 823-837.
9.
Behr, H. J.2002: Magadiite and magadiite-chert: a critical analysis of the silica sediments in Lake Magadi Basin, Kenya. In Renaut, R. W. and Ashley, G. M., editors, Sedimentation in continental rifts. SEPM Special Publications, 257-73.
10.
Bessems, I., Verschuren, D., Russell, J. M., Hus, J. and Cumming, B.2007: Paleolimnological evidence for widespread late-18th century drought across equatorial East Africa. Palaeogeography, Palaeoclimatology, Palaeoecology in press.
11.
Birkett, C., Murtugudde, R. and Allan, T.1999: Indian Ocean climate event brings floods to East Africa’s lakes and the Sudd marsh. Geophysical Research Letters26, 1031-1034.
12.
Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M. N., Showers, W., Hoffmann, S., Lotti-Bond, R., Hajdas, I. and Bonani, G.2001: Persistent solar influence on North Atlantic climate during the Holocene. Science294, 2130-2136.
13.
Brown, E. T. and Johnson, T. C.2005: Coherence between tropical East African and South American records of the Little Ice Age. Geochemistry, Geophysics, Geosystems6, doi: 10.1029/2005GC000959.
14.
Charles, C. D., Cobb, K. M., Moore, M. D. and Fairbanks, R. G.2003: Monsoon-tropical ocean interaction in a network of coral records spanning the 20th century. Marine Geology201, 207-222.
15.
Cohen, A. S., Palacios-Fest, M. R., Msaky, E. S., Alin, S. R., McKee, B. A., O’Reilly, C. M., Dettman, D. L., Nkotagu, H. and Lezzar, K. E.2005: Paleolimnological investigations of anthropogenic environmental change in Lake Tanganyika: IX. Summary of paleorecords of environmental change and catchment deforestation at Lake Tanganyika and impacts on the Lake Tanganyika ecosystem. Journal of Paleolimnology34, 125-145.
16.
Dean, W.1974: Determination of carbonate and organic matter in calcareous sediments and sedimentary rocks by loss on ignition: comparison with other methods. Journal of Sedimentary Petrology44, 242-248.
17.
DeMenocal, P. and Rind, D.1996: Sensitivity of subtropical African and Asian climate to prescribed boundary condition changes: model implications for the Plio-Pleistocene evolution of low-latitude climate. In Johnson, T. C. and Odada, E. O., editors, The limnology, climatology, and paleoclimatology of the East African lakes. Gordon and Breach, 57-77.
18.
Eakins, J. D. and Morrison, R. T.1978: A new procedure for the determination of lead-210 in lake and marine sediments. International Journal of Applied Radioactive Isotopes29, 531-536.
19.
Eugster, H. P. and Hardie, L. A.1978: Saline lakes. In Lerman, A. J., editor, Lakes: chemistry, geology, physics. Springer, 237-289.
20.
Gasse, F.2000: Hydrological changes in the African tropics since the Last Glacial Maximum. Quaternary Science Reviews19, 189-211.
Gasse, F., Barker, P. and Johnson, T. C.2002: A 24,000 year diatom record from the northern basin of Lake Malawi. In Odada, E. O. and Olgao, D., editors, The East African Great Lakes: limnology, palaeolimnology, biodiversity. Kluwer Academic Publishing, 548-549.
23.
Halfman, J. D., Johnson, T. C. and Finney, B.1994: New AMS dates, stratigraphic correlations and decadal climate cycles for the past 4 ka at Lake Turkana, Kenya. Palaeogeography, Palaeoclimatology, Palaeoecology111, 83-98.
24.
Jones, B. F. and DeoCampo, D. M.2002: Geochemistry of saline lakes. In Drever, J. I., editor, Surface and ground water, weathering, erosion, and soils. Treatise on geochemistry 5. Elsevier Science, 393-424.
25.
Jones, B. F., Rettig, S. L. and Eugster, H. P.1967: Silica in alkaline brines. Science158, 1310-1314.
26.
Jones, B. F., Eugster, H. P. and Rettig, S. L.1977: Geochemistry of the Lake Magadi basin, Kenya. Geochimica et Cosmochimica Acta41, 53-72.
27.
Karlen, W., Fastook, J. L., Holmgren, K., Malmstrom, M., Matthews, J. A., Odada, E. O., Risberg, J., Rosqvist, G., Sandgren, P., Shemesh, A. and Westerberg, L. O.1999: Glacier fluctuations on Mount Kenya since/~6000 cal. years BP: implications for climatic change in Africa. Ambio28, 409-418.
28.
Kelts, K. and Hsü, K. J.1978: Freshwater carbonate sedimentation. In Lerman, A., editor, Lakes: chemistry, geology, physics. Springer, 295-323.
29.
Lærdal, T. and Talbot, M. R.2002: Basin neotectonics of Lakes Edward and George, East African Rift. Palaeogeography, Palaeoclimatology, Palaeoecology187, 213-232.
30.
Lærdal, T., Talbot, M. R. and Russell, J. M.2002: Late Quaternary sedimentation and climate in the Lakes Edward and George area, Uganda-Congo. In Odada, E. O. and Olgao, D., editors, The East African Great Lakes: limnology, palaeolimnology, biodiversity. Kluwer Academic Publishers, 429-470.
31.
McHugh, M. J.2004: Near-surface zonal flow and East African precipitation receipt during austral summer. Journal of Climate17, 4070-4079.
32.
Mees, F., Verschuren, D., Nijs, R. and Dumont, H. J.1991: Holocene evolution of the crater lake at Malha, Northwest Sudan. Journal of Paleolimnology5, 227-253.
33.
Melack, J. M.1978: Morphometric, physical, and chemical features of the volcanic crater lakes of Western Uganda. Archiv für Hydrobiologie85, 430-453.
34.
Nicholson, S. E.1986: The spatial coherence of African rainfall anomalies: interhemispheric teleconnections. Journal of Climatology and Applied Meteorology25, 1365-1381.
35.
Nicholson, S. E.1995: Environmental change within the historical period. In Goudie, A. S., Adams, W. M. and Orme, A., editors, The physical geography of Africa. Oxford University Press, 60-75.
36.
Nicholson, S. E.1996: A review of climate dynamics and climate variability in Eastern Africa. In Johnson, T. C. and Odada, E. O., editors, The limnology, climatology, and paleoclimatology of the East African Lakes. Gordon and Breack Publishers, 25-56.
37.
Nicholson, S. E., Kim, J. and Ba, M. B.1997: The mean surface water balance over Africa and its interannual variability. Journal of Climate10, 2981-3002.
38.
Owen, R. B., Crossley, R., Johnson, T. C., Tweddle, D., Kornfield, I., Davidson, S., Eccles, D. H. and Engstrom, D. R.1990: Major low levels of Lake Malawi and implications for speciation rates in cichlide fishes. Royal Society of London Proceedings Series B240, 519-553.
39.
Robertshaw, P., Taylor, D., Doyle, S. and Marchant, R.2004: Famine, climate, and crisis in Western Uganda. In Past climate variability through Europe and Africa. Battarbee, R. W., Gasse, F. and Stickley, C. E., editors, Developments in Palaeoenvironmental Research. Springer, 535-547.
40.
Russell, J. M. and Johnson, T. C.2005a: Late Holocene climate change in the North Atlantic and Equatorial Africa: millennial-scale ITCZ migration. Geophysical Research Letters32, doi 10.1029/2005GL023295.
41.
Russell, J. M. and Johnson, T. C.2005b: A high-resolution geochemical record from Lake Edward, Uganda-Congo, and the timing and causes of tropical African drought during the late Holocene. Quaternary Science Reviews24, 1375-1389.
42.
Russell, J. M. and Johnson, T. C.2006: The water balance and stable isotope hydrology of Lake Edward, Uganda-Congo. Journal of Great Lakes Research32, 77-90.
43.
Russell, J. M., Johnson, T. C., Kelts, K. R., Lærdal, T. and Talbot, M. R.2003: An 11,000-year lithostratigraphic and paleohydrologic record from Equatorial Africa: Lake Edward, Uganda-Congo. Palaeogeography, Palaeoclimatology, Palaeoecology193, 25-49.
44.
Schnurrenberger, D. W., Russell, J. M. and Kelts, K. R.2003: Classification of lacustrine sediments based on sedimentary components. Journal of Paleolimnology29, 141-154.
45.
Ssemmanda, I., Ryves, D. B., Bennike, O. and Appleby, P. G.2005: Vegetation history in western Uganda during the last 1200 years: a sediment-based reconstruction from two crater lakes. The Holocene15, 119-132.
46.
Stager, J. C., Ryves, D. B., Cumming, B., Meeker, L. and Beer, J.2005: Solar variability and the levels of Lake Victoria, East Africa, during the last millennium. Journal of Paleolimnology33, 243-251.
47.
Stuiver, M. and Reimer, P. J.1993: Extended 14C database and revised CALIB radiocarbon cailbration program. Radiocarbon35, 215-230.
48.
Stuiver, M., Reimer, P. J., Bard, E., Beck, J. W., Burr, G. S., Hughen, K. A., Kromer, B., McCormac, F. G., van der Plicht, J. and Spurk, M.1998: INTCAL98 radiocarbon age calibration, 24,000 0 cal BP. Radiocarbon40, 1041-1083.
49.
Taylor, D., Robertshaw, P. and Marchant, R.2000: Environmental change and political upheaval in precolonial western Uganda. The Holocene10, 527-536.
50.
Thompson, L. G., Mosley-Thompson, E., Davis, M. E., Henderson, K. A., Brecher, H. H., Zagorodnov, V. S., Mashiotta, T. A., Lin, P., Mikhalenko, V. N., Hardy, D. R. and Beer, J.2002: Kilimanjaro ice core records: evidence of Holocene climate change in tropical Africa. Science298, 589-593.
51.
Verschuren, D.2001: Reconstructing fluctuations of a shallow East African lake during the past 1800 years from sediment stratigraphy in a submerged crater basin. Journal of Paleolimology25, 297-311.
52.
Verschuren, D.2004: Decadal and century-scale climate variability in tropical Africa during the past 2,000 years. In Battarbee, R. W., editor, Past climate variability through Europe and Africa. Paleoenvironmental Research Book Series, Elsevier.
53.
Verschuren, D., Laird, K. R. and Cumming, B.2000: Rainfall and drought in equatorial East Africa during the past 1,100 years. Nature403, 410-414.
54.
Wright, H. E., Jr1967: A square-rod piston sampler for lake sediments. Journal of Sedimentary Petrology37, 975-976.
55.
Wright, H. E., Jr1980: Coring of soft lake sediments. Boreas9, 107-114.
