Lake Malawi 700 Year TEX86 Surface Water Temperature Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: Please cite original reference when using these data, plus the data file URL and date accessed. NAME OF DATA SET: Lake Malawi 700 Year TEX86 Surface Water Temperature Reconstruction LAST UPDATE: 8/2012 (Original receipt by WDC Paleo) CONTRIBUTORS: Powers, L.A., T. C. Johnson, J.P. Werne, I.S. Castañeda, E.C. Hopmans, J.S. Sinninghe Damsté, and S. Schouten IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2012-140 WDC PALEO CONTRIBUTION SERIES CITATION: Powers, L.A., et al. 2012. Lake Malawi 700 Year TEX86 Surface Water Temperature Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2012-140. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Powers, L.A., T. C. Johnson, J.P. Werne, I.S. Castañeda, E.C. Hopmans, J.S. Sinninghe Damsté, and S. Schouten. 2011. Organic geochemical records of environmental variability in Lake Malawi during the last 700 years, Part I: The TEX86 temperature record. Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 303, pp. 133-139. doi:10.1016/j.palaeo.2010.09.006 ABSTRACT: We have applied the TEX86 paleothermometer to produce a surface water temperature record for Lake Malawi spanning the past 700 years. Over much of the record temperature fluctuates from ~24-27°C with a mean of ~25°C; however, there has been a substantial increase in temperature of ~2.0°C during the past ~ 100 years. The TEX86 temperature record reveals a strong similarity to the instrumental record; both records demonstrate warming (~0.7-1.4°C) over the past ~50 years as well as a cooling anomaly around 1959. Comparison of the TEX86 temperature record with the proxy records of primary productivity suggests that wind induced upwelling and/or precipitation have a strong influence on the surface temperature of Lake Malawi. ADDITIONAL REFERENCE: Powers, L.A., T.C. Johnson, J.P. Werne, I.S. Castañeda, E.C. Hopmans, J.S. Sinninghe Damsté, and S. Schouten. 2005. Large temperature variability in the southern African tropics since the Last Glacial Maximum. Geophysical Research Letters, 32, L08706, doi:10.1029/2004GL022014. GEOGRAPHIC REGION: East Africa PERIOD OF RECORD: 700 YrBP - present FUNDING SOURCES: US National Science Foundation (ATM-0502456), US NOAA (NA06OAR4310113). DATA FILE URLS: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/malawi2011.txt ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/malawi2011.xls DESCRIPTION: Surface water 700 year temperature reconstruction for Lake Malawi, East Africa, produced using the TEX86 paleothermometer. Three cores collected during the 1998 International Decade for East African Lakes (IDEAL) expedition in the north basin of Lake Malawi were used in this study. Splicing data from multi-cores M98-11MCA and M98-11MCB, and gravity trigger core M98-2PG, results in a record spanning the past ~700 years. Sediment samples (~1-2 g dry weight) were collected from the cores and analyzed for TEX86 as described in Powers et al. (2005). We have applied the mean annual lake surface temperature (ALST) calibration equation, ALST=55.0*TEX86-14.0 Lake Malawi core M98-11MCA/B: 10°00.2'S, 34°17.3'E, water depth 404m. Lake Malawi core M98-2PG: 9°58.6'S, 34°13.8'E, water depth 363m. DATA: Powers et al. 2011 Table 1, Lake Malawi TEX86 Temperature Sample Depth TEX86 Replicate analyses 1-4 Core (cm) Age 1 2 3 4 MeanTEX86 Std.Dev. Temperature°C M98 11MCA surface 1996 0.771 0.770 0.735 0.737 0.753 0.020 27.43 M98 11MCA 1.5 1992 0.751 0.744 0.738 0.737 0.742 0.007 26.84 M98 11MCA 3 1981 0.755 0.755 0.731 0.732 0.743 0.013 26.87 M98 11MCA 6 1965 0.748 0.738 0.743 0.007 26.85 M98 11MCB 7.5 1959 0.713 0.722 0.710 0.715 0.006 25.33 M98 11MCA 8 1954 0.735 0.738 0.733 0.735 0.003 26.44 M98 11MCA 11 1933 0.750 0.736 0.743 0.010 26.88 M98 11MCB 13.5 1915 0.720 0.723 0.718 0.720 0.003 25.61 M98 11MCB 15.5 1903 0.708 0.708 24.96 M98 11MCA 19 1880 0.704 0.698 0.698 0.700 0.003 24.50 M98 11MCB 23.5 1851 0.713 0.713 25.24 M98 11MCA 28 1806 0.733 0.719 0.717 0.723 0.009 25.76 M98 11MCB 33.5 1765 0.695 0.696 0.696 0.000 24.27 M98-11MCA 37.5 1732 0.706 0.706 24.81 M98 11MCA 40 1726 0.722 0.728 0.725 0.005 25.89 M98 11MCB 41.5 1704 0.714 0.710 0.712 0.003 25.17 M98 11MCB 42.5 1701 0.716 0.706 0.711 0.007 25.10 M98 11MCA 42.75 1698 0.719 0.729 0.713 0.720 0.008 25.61 M98 11MCB 43.5 1691 0.658 0.668 0.666 0.664 0.005 22.50 M98 11MCA 44 1689 0.731 0.716 0.712 0.720 0.010 25.58 M98 11MCB 45.5 1679 0.655 0.673 0.664 0.013 22.52 M98 11MCA 46 1676 0.716 0.716 25.35 M98 2PGA 39 1671 0.686 0.678 0.682 0.006 23.51 M98 11MCB 47.75 1665 0.706 0.699 0.705 0.706 0.704 0.003 24.72 M98 11MCB 51.5 1643 0.697 0.692 0.695 0.004 24.20 M98 2PGA 45 1630 0.702 0.702 0.692 0.699 0.699 0.005 24.43 M98 2PGA 50 1589 0.717 0.717 25.45 M98 2PGA 55 1544 0.723 0.723 25.74 M98 2PGA 60 1500 0.704 0.704 24.71 M98 2PGA 65 1465 0.692 0.682 0.687 0.007 23.79 M98 2PGA 70 1425 0.712 0.710 0.711 0.002 25.11 M98 2PGA 75 1395 0.703 0.703 24.66 M98 2PGA 80 1357 0.700 0.706 0.703 0.004 24.66 M98 2PGA 85 1316 0.728 0.725 0.711 0.721 0.009 25.66 M98 2PGA 90 1291 0.701 0.701 24.57 M98 2PGA 93 1283 0.706 0.706 24.82