Multiple episodes of rifting in Central and East Africa: A re-evaluation of gravity data

1994 ◽  
Vol 83 (4) ◽  
Author(s):  
C.J. Ebinger ◽  
A. Ibrahim
Keyword(s):  
East Africa ◽  
Gravity Data ◽  
Multiple Episodes

scholarly journals How isostasy explains continental rifting in East Africa?

2020 ◽  
Author(s):  
Mohammad Bagherbandi ◽  
Nureldin A. A. Gido
Keyword(s):  
East Africa ◽  
Rift Valley ◽  
Plate Tectonics ◽  
Gravity Data ◽  
Density Contrast ◽  
Earthquake Activity ◽  
Continental Rifting ◽  
The Earth ◽  
Geodynamic Processes ◽  
Thin Crust

<p>The principle of isostasy plays an important role to understand the relation between different geodynamic processes. Although, it is difficult to find an exact method that delivers a complete image of the Earth structure. However, gravimetric methods are alternative to provide images of the interior of the Earth. The Earth’s crust parameters, i.e. crustal depth and crust-mantle density contrast, can reveal adequate information about the solid Earth system such as volcanic activity, earthquake and continental rifting. Hence, in this study, a combine Moho model using seismic and gravity data is determined to investigate the relationship between the isostatic state of the lithosphere and seismic activities in East Africa. Our results show that isostatic equilibrium and compensation states are closely correlated to the seismicity patterns in the study area. For example, several studies suggest that African superplume causes the rift valley, and consequently differences in crustal and mantle densities occur. This paper presents a method to determine the crustal thickness and crust-mantle density contrast and consequently one can observe low-density contrast (about 200 kg/m<sup>3</sup> ) and thin crust (about 30 km) near the triple junction plate tectonics in East Africa (Afar Triangle), which confirms the state of overcompensation in the rift valley areas. Furthermore, the density structure of the lithosphere shows a large correlation with the earthquake activity, sub-crustal stress and volcanic distribution across East Africa.</p>

Drawers of Water II: assessing change in domestic water use in East Africa

Waterlines ◽  
2003 ◽  
Vol 22 (1) ◽  
pp. 22-25 ◽  
Author(s):  
John Thompson ◽  
Ina Porras ◽  
Munguti Katui-Katua ◽  
Mark Mujwahuzi ◽  
James Tumwine
Keyword(s):  
East Africa ◽  
Water Use ◽  
Domestic Water

Coffee and qat on the Royal Danish expedition to Arabia – botanical, ethnobotanical and commercial observations made in Yemen 1762–1763

2015 ◽  
Vol 42 (1) ◽  
pp. 101-112
Author(s):  
I. Friis
Keyword(s):  
East Africa ◽  
Arabian Peninsula ◽  
Made In

In spite of widespread consumption of coffee in Europe at the time of the Royal Danish expedition to Arabia 1761–1767, little was known of the cultivation of coffee in Yemen and of the Arabian coffee export to Europe. Fresh leaves of qat were used as a stimulant on the Arabian Peninsula and in East Africa, but before the Royal Danish expedition to Arabia this plant was known in Europe only from secondary reports. Two members of the expedition, Carsten Niebuhr and Peter Forsskål, pioneered studies of coffee and qat in Yemen and of the Arabian coffee export. Linnaeus' instructions for travellers requested observations on the use of coffee, but otherwise Forsskål and Niebuhr's studies of coffee and qat were made entirely on their own initiative. Now, 250 years after The Royal Danish expedition to Arabia, coffee has become one of the world's most valuable trade commodities and qat has become a widely used and banned drug.

Sign in / Sign up

Export Citation Format

Share Document