scholarly journals EA3W7-1 The effects of the Great Rift Valley and climate changes on the distribution of malaria vectors in East Africa

2001 ◽  
Vol 52 (Supplement) ◽  
pp. 131
Author(s):  
Noboru MINAKAWA ◽  
Guiyun YAN ◽  
Motoyoshi MOGI
Keyword(s):  
East Africa ◽  
Rift Valley ◽  
Climate Changes ◽  
Malaria Vectors ◽  
Great Rift Valley

Etat actuel des connaissances sur le volcan Niragongo (Republique democratique du Congo)

1966 ◽  
Vol S7-VIII (2) ◽  
pp. 176-200 ◽  
Author(s):  
Haroun Tazieff
Keyword(s):  
Chemical Composition ◽  
East Africa ◽  
Gaseous Phase ◽  
Rift Valley ◽  
Accessory Minerals ◽  
République Démocratique Du Congo ◽  
Great Rift Valley

Abstract The Niragongo volcano of the Congo region is located in the western Great Rift Valley in east Africa. The cone is formed of feldspathoidal lavas containing augite and accessory minerals, and the crater contains terraces representing ancient lava levels. Studies were conducted on the chemical composition and petrography of the rocks, on the chemistry of the gases and sublimates, and on the temperature of the lavas. The magnetic and gravimetric values for the volcano and the area were measured and energy discharge was estimated. The study confirmed the importance of the gaseous phase in volcanic phenomena.

Contributions to the Petrology of British East Africa

1903 ◽  
Vol 13 (61) ◽  
pp. 228-263 ◽  
Author(s):  
G. T. Prior
Keyword(s):  
East Africa ◽  
Rift Valley ◽  
Volcanic Rocks ◽  
Central Africa ◽  
British Museum ◽  
Basaltic Rocks ◽  
Basement Rocks ◽  
Great Rift Valley ◽  
Rock Specimens

The following notes on the petrology of British East Africa are the result of an examination of rock-specimens collected by Professor J. W. Gregory on his well-known expedition from Mombasa to Mt. Kenya and Lake Baringo in 1892-3, and of rock-collections from the Uganda Protectorate which have been recently presented to the British Museum by Sir Harry Johnston.The collections include examples of the Archaean gneisses, schists, and granites which constitute the prevailing basement rocks of Central Africa; of ferruginotls schists, coarse sandstones, and quartzites belonging to the Palaeozoic Karagwe series ; and of an interesting series of Tertiary volcanic rocks comprising phonolites, phonolltic traehytes, riebeckite-rhyolites, kenytes, and basalts from the volcanoes of the Great Rift Valley, as well as of nephelinites and basaltic rocks containing melilite and perofskite from Mr. Elgon.

A New Ceratotrochus from the Upper Cretaceous of Portuguese East Africa

1930 ◽  
Vol 67 (10) ◽  
pp. 475-477 ◽  
Author(s):  
J. W. Gregory
Keyword(s):  
East Africa ◽  
Rift Valley ◽  
Upper Cretaceous ◽  
Great Rift Valley

Three small simple corals were collected by Mr. F. P. Mennell from the Upper Cretaceous of the Cheringoma district, Portuguese East Africa. The area is of special geological interest as it includes the southern end of the Great Rift Valley and furnishes useful evidence as to the date of the formation of that valley. A coral from almost the same horizon has been figured by Schlosser, and, as it is clearly a different species, the horizon may be expected to yield a good fauna of simple corals.

The Great Rift Valley in Northern German East Africa

1914 ◽  
Vol 44 (5) ◽  
pp. 494
Author(s):  
J. W. G. ◽  
Fritz Jaeger
Keyword(s):  
East Africa ◽  
Rift Valley ◽  
German East Africa ◽  
Great Rift Valley

The hominin lineage

2017 ◽  
Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde
Keyword(s):  
Rift Valley ◽  
Climate Changes ◽  
Human Lineage ◽  
Terrestrial Locomotion ◽  
Geological Formations ◽  
Difficult Issue ◽  
Human Fossils

This chapter describes the origin of the human lineage within the evolution of the hominoids, which raises the difficult issue of how to integrate the evolution of dentition and terrestrial locomotion. Next is the investigation of the appearance and initial dispersal of the hominins toward the end of the Miocene, with particular attention to the models of colonization of new territories as a function of climate changes. The hypothesis of the adaptation to the open savanna by bipedalism is explored. Finally, there is a summary description of the different deposits and localities of the main African localities with human fossils, pointing out the different geological formations and exemplars found in each deposit, including two sites north of the Rift Valley of great importance: Toros-Menalla (Tchad) and Dmanisi (Georgia).

scholarly journals Water Erosion Risk Assessment in the Kenya Great Rift Valley Region

2021 ◽  
Vol 13 (2) ◽  
pp. 844
Author(s):  
George Watene ◽  
Lijun Yu ◽  
Yueping Nie ◽  
Jianfeng Zhu ◽  
Thomas Ngigi ◽  
...  
Keyword(s):  
Rift Valley ◽  
Soil Loss ◽  
Large Change ◽  
Risk Category ◽  
Lake Nakuru ◽  
Erosion Risk ◽  
Erosion Rates ◽  
3.0 T ◽  
Great Rift Valley ◽  
Loss Rates

The Kenya Great Rift Valley (KGRV) region unique landscape comprises of mountainous terrain, large valley-floor lakes, and agricultural lands bordered by extensive Arid and Semi-Arid Lands (ASALs). The East Africa (EA) region has received high amounts of rainfall in the recent past as evidenced by the rising lake levels in the GRV lakes. In Kenya, few studies have quantified soil loss at national scales and erosion rates information on these GRV lakes’ regional basins within the ASALs is lacking. This study used the Revised Universal Soil Loss Equation (RUSLE) model to estimate soil erosion rates between 1990 and 2015 in the Great Rift Valley region of Kenya which is approximately 84.5% ASAL. The mean erosion rates for both periods was estimated to be tolerable (6.26 t ha−1 yr−1 and 7.14 t ha−1 yr−1 in 1990 and 2015 respectively) resulting in total soil loss of 116 Mt yr−1 and 132 Mt yr−1 in 1990 and 2015 respectively. Approximately 83% and 81% of the erosive lands in KGRV fell under the low risk category (<10 t ha−1 yr−1) in 1990 and 2015 respectively while about 10% were classified under the top three conservation priority levels in 2015. Lake Nakuru basin had the highest erosion rate net change (4.19 t ha−1 yr−1) among the GRV lake basins with Lake Bogoria-Baringo recording annual soil loss rates >10 t ha−1 yr−1 in both years. The mountainous central parts of the KGRV with Andosol/Nitisols soils and high rainfall experienced a large change of land uses to croplands thus had highest soil loss net change (4.34 t ha−1 yr−1). In both years, forests recorded the lowest annual soil loss rates (<3.0 t ha−1 yr−1) while most of the ASAL districts presented erosion rates (<8 t ha−1 yr−1). Only 34% of all the protected areas were found to have erosion rates <10 t ha−1 yr−1 highlighting the need for effective anti-erosive measures.

The Nyasaland Section of the Great Rift Valley: Discussion

1926 ◽  
Vol 68 (2) ◽  
pp. 137
Author(s):  
Sidney Harmer ◽  
Alfred Sharpe ◽  
A. E. Kitson ◽  
F. Dixey
Keyword(s):  
Rift Valley ◽  
Great Rift Valley
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