TY - JOUR
T1 - Late Quaternary TEX86 paleotemperatures from the world’s largest desert lake, Lake Turkana, Kenya
AU - Morrissey, Amy
AU - Scholz, Christopher A.
AU - Russell, James M.
N1 - Funding Information:
We thank the government of Kenya for research permissions. Financial support was provided by the sponsors of the Syracuse University Lacustrine Rift Basins Research Program. We also thank the National Oil Corporation of Kenya for assistance during field operations. The authors thank the people of Loiyangalani and the Turkana Rift Valley, for their cooperation, assistance, and hospitality during multiple field seasons at Lake Turkana. We would also like to thank Dr. Shannon Loomis, Dr. Rafael Tarozo, and Lily Cohen for assistance with sample preparations and laboratory procedures at Brown University. We also thank Dr. Bruce Wilkinson for his comments and suggestions on early versions of this manuscript.
Publisher Copyright:
© 2017, Springer Science+Business Media Dordrecht.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Wetter climatic conditions prevailed across northern and Equatorial Africa during the terminal Pleistocene until the middle Holocene, a climate event known as the “African Humid Period” (AHP). Although hydrologic changes during this period are well-known, very few records of temperature are available for evaluating the mechanisms and dynamics of climate change during the AHP across tropical Africa. To quantify changes in temperature during the onset and termination of the AHP, the TEX86 temperature proxy was used to generate a 14,000 year record of the surface temperature of Lake Turkana. This biomarker and related measures have been used to reconstruct regional and high-latitude paleotemperatures from the oceans and other continental systems, including other large African lakes. Although Lake Turkana’s climate and hydrology are very different from other large African lakes, our reconstruction exhibits a temperature history that shares a number of climatic trends with previous reconstructions. The TEX86 temperatures from Lake Turkana from 14 to 0.4 ka range from 24.3 to 28.6 °C, with a gradual decrease in temperature from early to late Holocene. This cooling roughly follows northern hemisphere summer insolation, similar to the trend observed in Lake Victoria and other regional records. However, the record from Turkana contains many abrupt temperature shifts not seen in other large lakes in the region. Multi-century-scale fluctuations persist through most of the record, and can be attributed to periods of lake mixing. Larger temperature perturbations are likely associated with changes in evaporation and cloud cover.
AB - Wetter climatic conditions prevailed across northern and Equatorial Africa during the terminal Pleistocene until the middle Holocene, a climate event known as the “African Humid Period” (AHP). Although hydrologic changes during this period are well-known, very few records of temperature are available for evaluating the mechanisms and dynamics of climate change during the AHP across tropical Africa. To quantify changes in temperature during the onset and termination of the AHP, the TEX86 temperature proxy was used to generate a 14,000 year record of the surface temperature of Lake Turkana. This biomarker and related measures have been used to reconstruct regional and high-latitude paleotemperatures from the oceans and other continental systems, including other large African lakes. Although Lake Turkana’s climate and hydrology are very different from other large African lakes, our reconstruction exhibits a temperature history that shares a number of climatic trends with previous reconstructions. The TEX86 temperatures from Lake Turkana from 14 to 0.4 ka range from 24.3 to 28.6 °C, with a gradual decrease in temperature from early to late Holocene. This cooling roughly follows northern hemisphere summer insolation, similar to the trend observed in Lake Victoria and other regional records. However, the record from Turkana contains many abrupt temperature shifts not seen in other large lakes in the region. Multi-century-scale fluctuations persist through most of the record, and can be attributed to periods of lake mixing. Larger temperature perturbations are likely associated with changes in evaporation and cloud cover.
KW - East Africa
KW - Lake Turkana
KW - Paleotemperature
KW - Quaternary paleoclimatology
KW - TEX86
UR - http://www.scopus.com/inward/record.url?scp=85009795036&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85009795036&partnerID=8YFLogxK
U2 - 10.1007/s10933-016-9939-6
DO - 10.1007/s10933-016-9939-6
M3 - Article
AN - SCOPUS:85009795036
SN - 0921-2728
VL - 59
SP - 103
EP - 117
JO - Journal of Paleolimnology
JF - Journal of Paleolimnology
IS - 1
ER -