Lake Sediment Records of Environmental and Climatic Changes from Northern Ethiopia (Lake Ashange)
| dc.contributor.advisor | Umer, Mohammed (PhD) | |
| dc.contributor.author | Kubsa, Zelalem | |
| dc.date.accessioned | 2021-12-14T05:28:29Z | |
| dc.date.accessioned | 2023-11-18T09:55:24Z | |
| dc.date.available | 2021-12-14T05:28:29Z | |
| dc.date.available | 2023-11-18T09:55:24Z | |
| dc.date.issued | 2005 | |
| dc.description.abstract | Lacustrine sediments can be used to study the palaeoenvironmental evolution of a particular catchment. This is because they reflect developments in the Lake Ecosystem and productivity as weU as changes in the rate and type of processes of the catchment such as weathering, erosion and sediment transport. Moreover, they are often deposited in undisturbed sedimentary environments and give time-integrated infonnauon on the evolution of the basin and its surroundings. The aim of the present work is to contribute to the understanding of the Holocene evol ution of climate variability and environmental changes due to both climatic and human causes in Northern Ethiopia from the sediments of lake cores and shorel ines as well as from sections collected in and around Lake Ashange in the year 2003 under the Lake Tana project. The studied core is dominantly organic and measures 8.1 m and is recovered under 9m of water depth. The basal radiocarbon age shows a date of 11 ,920 ± 40 years BP. More radiocarbon dates, from samples corresponding to important shifts in the studied proxies, are under analysis. Because of this, linear extrapolation of age versus sediment depth has been applied in this study by considering the top of the core as modem. Sediments were also analyzed for lithology. magnetic susceptibil ity, X-ray diffraction [(XRD) Mineralogy] and X-ray fluorescence [(XRF) (Elemenllil analysis)]. Moreover water samples were collected for chemical analysis and secondary information was also gathered from hydrometeorological data as well as from aerial photographs of 1965, 1980 and 1986. The integrated analyses gave the first evidences of continuous and high resolution climatic and environmental changes for the late Pleistocene and Holocene of Northern Ethiopia. The core was subdivided into four zones corresponding to important changes relative to the studied parameters. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/29266 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa, Ethiopia | en_US |
| dc.title | Lake Sediment Records of Environmental and Climatic Changes from Northern Ethiopia (Lake Ashange) | en_US |
| dc.type | Thesis | en_US |