全部文献期刊学位论文会议报纸专利标准年鉴图书|学者科研项目
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作者:Mohammed Umer , Henry F. Lamb ...
来源:[J].Quaternary International(IF 1.962), 2012, Vol.274, pp.25-37Elsevier
摘要:Abstract(#br)East African paleoenvironments are highly variable, marked by extreme fluctuations in moisture availability, which has far-reaching implications for the origin, evolution and dispersal of Homo sapiens in and beyond the region. This paper presents results from a ...
作者:... Giandomenico Fubelli , Mohammed Umer , Asfawossen Asrat
来源:[J].Journal of African Earth Sciences(IF 1.229), 2009, Vol.56 (4), pp.131-138Elsevier
摘要:Abstract(#br)Landslide hazard is one of the crucial environmental constraints for the development of Ethiopia, representing a limiting factor for urbanization and infrastructures. The high relief and the rugged topography induced by a strong Plio-Quaternary uplift, the occur...
作者:... Zelalem Kubsa , Mohammed Umer , Charlotte Bryant
来源:[J].Palaeogeography, Palaeoclimatology, Palaeoecology(IF 2.745), 2009, Vol.279 (1), pp.114-127Elsevier
摘要:Abstract(#br)Lake Ashenge, a closed-basin lake near the northernmost penetration of summer monsoon rains, is well placed to provide a continental record of past changes in the strength of the African monsoon system. Diatom and oxygen isotope analyses of the lake sediments confirm...
作者:... David Turton , Miguel Sevilla-Callejo , Mohammed Umer
来源:[J].Global Environmental Change(IF 5.236), 2010, Vol.20 (4), pp.612-626Elsevier
摘要:Abstract(#br)Bush encroachment is a significant phenomenon in savanna environments as it affects wildlife and local livelihoods by preventing new pasture generation. In this article we present a 2000-year record of vegetation change in the Dara range of the Mago National Park, so...
作者:... Charlotte Bryant , Dominique Genty , Mohammed Umer
来源:[J].Geochimica et Cosmochimica Acta(IF 3.884), 2007, Vol.71 (12), pp.2975-2988Elsevier
摘要:Abstract(#br)We combine surface and cave climate monitoring with multiple stalagmite parameters to help understand and calibrate the climate records contained within stalagmites from a region with strong rainfall seasonality. Two actively growing stalagmites from Ethiopia we...
作者:Mohammed Umer , Gilberto Calderoni
来源:[J].Quaternary Research(IF 2.204), 2003, Vol.60 (3), pp.274-283Elsevier
摘要:Abstract(#br)Stratigraphic analysis of alluvial/colluvial sequences and 14 C dating have been used as proxies for Holocene climate changes in the highlands of Tigray (northern Ethiopia). The studied records show alternations of buried soils and peaty–clayey sediments, pointi...
作者:Mohammed Umer , Michael DiBlasi
来源:[J].Palaeogeography, Palaeoclimatology, Palaeoecology(IF 2.745), 2009, Vol.282 (1), pp.67-80Elsevier
摘要:Abstract(#br)A long history of supporting sophisticated but unsustainable kingdoms makes the Tigray Plateau of the northern Ethiopian highlands a promising region for the study of relationships between palaeoenvironmental change and the trajectories of human civilizations. T...
作者:... Marcelo Alexandre , Mohammed Umer , Tsige Gebru
来源:[J].Catena(IF 1.881), 2010, Vol.85 (2), pp.130-143Elsevier
摘要:Abstract(#br)The Tigray Plateau of Ethiopia and Eritrea is vulnerable to environmental change, yet environmental influences on the rise and fall of the civilizations that once existed there are almost unexplored. We sampled sections of gully walls for palaeoenvironmental pro...
作者:Mohammed Umer , Sarah J. Davies
来源:[J].Quaternary Science Reviews(IF 4.076), 2007, Vol.26 (3-4), pp.287-299Elsevier
摘要:Abstract(#br)High-resolution seismic data from Lake Tana, the source of the Blue Nile in northern Ethiopia, reveal a deep sedimentary sequence divided by four strong reflectors. Data from nearshore cores show that the uppermost strong reflector represents a stiff silt unit, inter...
作者:... Melanie J. Leng , Mohammed Umer , Charlotte Bryant
来源:[J].Global and Planetary Change(IF 3.155), 2011, Vol.78 (3), pp.147-161Elsevier
摘要:Abstract(#br)Magnetic and geochemical core data spanning the last 17,000 years are correlated with new seismic stratigraphy from Lake Tana, Ethiopia, to infer past lake-level change and hence effective precipitation. The data confirm that low lake-level coincides with Heinrich Ev...

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