PhD Graduation, Omuombo, Christine Atieno

omuombo

 

Christine Omuombo is a geoscientist, consultant and an academic coach based at the University of Nairobi, Department of Geology as a Lecturer.

She has more than 12 years of experience in water, climate, environment, and population dynamics in an effort to understand the climate and human impact on the environment in the past and present landscapes. She began her academic career in Kenya as a Geology major at the University of Nairobi and later obtained a Joint European MSc in Water and Coastal Management from three European universities through an Erasmus Mundus Scholarship. She recently graduated with a DOCTOR OF PHILOSOPHY IN GEOLOGY from the University of Nairobi. Her PhD work focused on understanding long term changes using lake sediment records and the application of biogeochemistry to assess changes through time. This work has been done in collaboration with Sorbonne Université (UPMC) for laboratory support with a scholarship from the French Institute for Research (Institut de Recherche pour le Développement (IRD)) and the French government.

 

Thesis / Project  Title :Biogeochemical proxies of Environmental and Climate Change on Mount Kenya

 

Thesis / Project  Abstract:

Three crater lakes from Mount Kenya (Nkunga, Sacred and Rutundu) were studied to infer Late Holocene climate and environmental changes. These crater lakes are small closed lake basins with well-defined catchments that are sensitive to seasonal, interannual and long-term fluctuations. Consequently, they are promising archives for high-resolution reconstruction of climate and environmental change in Kenya. The aim of this study was to elucidate the Late Holocene history of climate and environmental changes on Mount Kenya using multi-proxy palaeo-indicators in soil and lake sediments. The multi-proxy analysis that was carried out on the Mount Kenya soils and lake sediments comprised traditional sedimentological (XRD, XRF and Xlf) and relatively novel organic geochemical analyses (%C, %N, δ13C, δ15N, n-alkanes and GDGT). The occurrence and timing of different events were established by AMS 14C dating of the cores. The results cover the last 4770 cal yr. BP to present. At the millennial scale, a wet early Holocene followed by a drier mid to late Holocene is observed. During the Late Holocene two key dry spells at ca. 4200 and 2800 cal yr. BP occur in the shallow lake phases at lakes Rutundu and Sacred. There is also evidence of a wet early little Ice Age (at Lakes Nkunga and Sacred) followed by drier conditions during the late phase of the Little Ice Age (Lake Nkunga). The multiproxy approach has enabled the identification of local catchment-scale effects on the individual lakes in addition to the observed regional climate effects.