Geology topics

Research about Ethiopia

Source-linked reports with geographic coverage including Ethiopia.

23 records · Page 2Linked to original sources

USGS2011

Estimating eruption temperature from thermal emission spectra of lava fountain activity in the Erta'Ale (Ethiopia) volcano lava lake: Implications for observing Io's volcanoes

We have analysed high-spatial-resolution and high-temporal-resolution temperature measurements of the active lava lake at Erta'Ale volcano, Ethiopia, to derive requirements for measuring eruption temperatures at Io's volcanoes. Lava lakes are particularly attractive targets because they are persistent in activity and large, often with ongoing lava fountain activity that exposes lava at near-eruption temperature. Using infrared thermography, we find that extracting useful temperature estimates from remote-sensing data requires (a) high spatial resolution to isolate lava fountains from adjacent cooler lava and (b) rapid acquisition of multi-color data. Because existing spacecraft data of Io's volcanoes do not meet these criteria, it is particularly important to design future instruments so that they will be able to collect such data. Near-simultaneous data at more than two relatively short wavelengths (shorter than 1 μ m) are needed to constrain eruption temperatures. Resolving parts of the lava lake or fountains that are near the eruption temperature is also essential, and we provide a rough estimate of the required image scale.

Erta'ale Volcano↗

USGS2005

Recent drought tendencies in Ethiopia and equatorial-subtropical eastern Africa

This report presents an analysis of Ethiopian rainfall from 1960 through 2004, based on 186 gauges in Ethiopia and 373 gauges from surrounding countriesi. Substantial post1997 declines in March-September rainfall have been observed in the northeast, southeast and southwestern portions of the country, a result corroborated by several independent data sourcesii. The observed rainfall reductions have been accompanied by an increase in millions needing food aid (Figure 1). The greatest percent decrease has occurred during the Belg (March-May) season, though Kiremt (June-September) rains have also diminished in many areas. This recent dryness may be linked to a warming tendency in the southern Indian Oceaniii, and is likely to impact densely populated and/or water-insecure regions of southern and eastern Ethiopia. These areas face declines in rainfall and increasing demands on land, water and agriculture. Recent dryness, dropping coffee prices, rising population and land degradation combine to create mounting destitution that must be countered with innovative planning and policiesiv. This report is organized as follows. Section 1 provides context for our results by summarizing recent trends in food aid, precipitation and the regional climate. Section 2 quantifies the water availability situation by analyzing potentially available runoff. Section 3 describes the results of our historical rainfall analysis. Section 4 relates the observed rainfall variations to circulation and sea surface temperature patterns in the Indian and Pacific Oceans. Section 5 briefly summarizes our results.

Equatorial-subtropical Africa↗

USGS2003

Estimating Meher crop production using rainfall in the 'Long Cycle' region of Ethiopia

Meher season crop production is well correlated with April-May rainfall in the Ethiopian 'long cycle' crop growing region. This relationship is used to estimate 2003 Meher small farmer gross production at 87 =B1 10 million quintals (8.7 million MT 2 =B1 1 million MT) of cereals, pulses and other crops, using data from the Central Statistical Authority (CSA). Assuming recent levels of commercial and food aid imports, Belg production and population growth, this estimate will produce a food deficit of about 23 million quintals (2.3 million MT) for 2003-04, smaller than the one experienced during 2002-03 (34 million Qt, or 3.4 million MT), but similar to the deficit experienced in 1997-98. A long-term negative rainfall trend in the southwestern highlands may be aggravating the situation. Increasing food requirements and decreasing precipitation point toward chronic food shortages in the near future.

FEWS NET Special Report↗

USGS1981

The seismicity of Ethiopia; active plate tectonics

"But I tell you, when you look at the way the pieces of the northeastern portion of the African continent seem to fit together, separated by a narrow gulf, you could almost make a believer [in continental drift] of anybody" Astronaut Harrison Schmidt, on the view from Apollo 17. Ethiopia, descended from the semimythical Kingdom of Punt, lies at the strategic intersection of Schmidt's jigsaw puzzle where the Red Sea, Gulf of Aden, and the African Rift System meet. Because of geologically recent uplift combined with rapid downcutting erosion by rivers, notably the Blue Nile (Abbay), Ethiopia is the most mountainous country in Africa. It is also the most volcanically active, while its historical seismicity matches that of the midocean ridges. And, in a sense, Ethiopia is host to an evoloving ocean ridge system.

Earthquake Information Bulletin (USGS)↗

USGS1971

Radiometric age determinations on Pliocene/Pleistocene formations in the lower Omo basin, Ethiopia

THE potassium–argon ages presented here were obtained during 1966 to 1969 in order to provide an absolute time scale for the stratigraphic work by the international Omo Research Expedition in the Pliocene/Pleistocene formations (unpublished work of F. H. B., J. de Heinzelin and F. C. Howell) in south-west Ethiopia. Although some of these dates are not new 1–3 , most of the analytical procedures and data have not been presented. We also present a list of fossil localities recorded by the University of Chicago contingent of the expedition within the Shungura Formation. Preliminary descriptions of the Hominidae have been published already 3,4 .

Nature↗