Authentic ELT Material Adaptation: Drawbacks, Prevalence and Solutions: The case of Wolkite University community school, Wolkite, Ethiopia.

This paper examines the contributing issues that enhance students learning through adapting ELT materials and assessing its effectiveness forwarding to take measures. The study used both qualitative and quantitative approaches. The study was conducted a research by developing questionnaire, observation and document analysis. The data were collected from principals, teachers, students and woreda education officers. The data collected were arranged and organized for analysis and interpretation. Based on the analysed data, the study found out that limitations in the implementation of authentic material adaptation and how to use various adaptive techniques. Teachers lack of motive and interest to design and select language materials that fit the curriculum and closely correspond with the aims of the teaching program and the needs of the students. Thus, the study recommended that adapted materials should be carefully evaluated and selected before being used for a language classroo

Poultry Feed Resources and Coping Mechanisms of Challenges in Sidama Zone, Southern Ethiopia

The study was conducted in Wondogenet and Shebedino woredas of Sidama zone with the objective of assessing the existing poultry feed resources, challenges and coping mechanisms. Multi stage sampling techniques were used. The potential supplementary feeds used were maize (17.85±2.21), household scraps (10.96±1.36) and cereal debris (9.05±1.08) gram per chicken per day. During the wet season of the year, 89.1% of the respondents feed scarcity was aggravated. Farmers were tackled poultry feed scarcity by feeding Enset (Ensete ventricosum)  by-products (30.8%), food left over and household wastes (13.3%), available major green feeds and non-conventional feed resources like growing worms and insect. The feed offered were entirely incomplete and inadequate. Therefore, efforts have to be made to design and implement interventions, aiming at improving poultry feed resource base and practices. Keywords: Challenges, Coping mechanism, poultry feed, Supplementation

Assessing Soil Nutrient Depletion to Household Food Insecurity in the Smallholders Farming System in the Western Hills of Lake Abaya, Ethiopia

Soil nutrient depletion is major environmental problems that threaten food security in Ethiopia, especially in the study area. It can be regarded as a direct result of the past agricultural practices in the area. In the study, an attempt has been made to examine the adverse effect of soil nutrient depletion to the household livelihood situation in the western hills of Lake Abaya, Ethiopia. To assess the research data methodologies such as soil analysis, food balance sheet, per capita food availability in kilocalories and multiple regression models were utilized. The laboratory analysis of soil had shown that organic matter, cation exchange capacity (CEC), available phosphorus and potassium content of the soil is progressively decreasing away from the homestead. The study further revealed that 61 percent of the household’s feed themselves for not more than nine months in a year against 28.2 percent, those from low-lying areas are self-sufficient. An analysis of this kind would help the local government to take timely intervention and help planners and donor agencies to include the problems as a priority area of intervention in their program. Keywords: Soil nutrient depletion, Food insecurity, Food balance sheet, Per capita food availability

Morphological characterization of fungal disease on tapped Boswellia papyrifera trees in metema and Humera districts, northern Ethiopia

Boswell papyrifera is a tree species which is found in Amhara, Tigray, and  Benshangul Gumuze region and used for the production of frankincense. Frequent tapping at different rounds and at different position of the tree is made to produce frankincense. A study aiming at evaluating the health status of tapped Boswellia papyrifera was carried out on samples obtained from Metema and Humera. Galls were commonly observed on most tapped Boswellia trees and a black wood discoloration was found on the wood beneath these galls. Isolation made from thediscolored part of the wood resulted in growth of fungal colonies with a white to gray fluffy aerial mycelia which later changed into blackish mycelial growth as it matures. The spore of the fungus has hyaline, ellipsoid to ovoid shaped and it has one septa. The spore has a rounded base and truncate apex. The color, the shape of the colony and the characteristics of the conidia is found to be identical with description of Lasiodiplodia theobromae. Hence, based on the morphological characteristics of the colony and the spore, the fungus isolated from symptomatic trees, is tentatively identified as Lasiodiplodia theobromae. Molecular characterization is essential to confirm the identity of the fungus. The pathogenicity test resulted into developmentof lesion depicting that the fungi isolated from Boswellia papyrifera can cause disease on the tree.Keywords: Boswellia, Incense production, Lasiodiplodia, Pathogen, Tappin

Probabilistic volcanic hazard assessment for pyroclastic density currents from pumice cone eruptions at Aluto Volcano, Ethiopia

Aluto volcano, in the Main Ethiopian Rift, is a peralkaline caldera system, which comprises conglomerations of rhyolite (obsidian) lavas and enigmatic pumice cones. Recent work at Aluto has found that pumice cone eruptions are highly unsteady, and form convective eruption plumes that frequently collapse to generate pyroclastic density currents (PDCs). We develop a methodology and present results for the first probabilistic volcanic hazard assessment (PVHA) for PDCs at a pumice cone volcano. By doing so, we estimate the conditional probability of inundation by PDCs around Aluto volcano, incorporating the aleatory uncertainty in PDC hazard. We employ a Monte Carlo energy cone modeling approach, which benefits from parameterization informed by field investigations and volcanic plume modeling. We find that despite the relatively modest eruptions that are likely to occur, the wide distribution of past vent locations (and thus the high uncertainty of where future vents might open), results in a broad area being potentially at risk of inundation by PDCs. However, the aleatory uncertainty in vent opening means that the conditional probabilities are lower (≤ 0.12), and more homogeneous, over the hazard domain compared to central-vent volcanoes (where conditional probabilities are often ≤ 1 close to the vent). Despite this, numerous settlements, amenities, and economically valuable geothermal infrastructure, lie within the most hazardous (P(PDC|eruption) ≥ 0.05) regions of Aluto caldera. The Monte Carlo energy cone modeling approach provides a quantitative, accountable and defendable background and long-term PVHA for PDCs from Aluto. These results could be combined in the future with hazard assessments relating to tephra fall and/or lava to develop a comprehensive volcanic hazard map for the caldera. Following appropriate parameterization, the approach developed here can also be used to compute a PDC PVHA at other volcanoes where vent location is uncertain

The eruptive history and magmatic evolution of Aluto volcano: new insights into silicic peralkaline volcanism in the Ethiopian rift

The silicic peralkaline volcanoes of the East African Rift are some of the least studied volcanoes on Earth. Here we bring together new constraints from fieldwork, remote sensing, geochronology and geochemistry to present the first detailed account of the eruptive history of Aluto, a restless silicic volcano located in a densely populated section of the Main Ethiopian Rift. Prior to the growth of the Aluto volcanic complex (before 500 ka) the region was characterized by a significant period of fault development and mafic fissure eruptions. The earliest volcanism at Aluto built up a trachytic complex over 8 km in diameter. Aluto then underwent large-volume ignimbrite eruptions at 316 ± 19 ka and 306 ± 12 ka developing a ~ 42 km2 collapse structure. After a hiatus of ~ 250 ka, a phase of post-caldera volcanism initiated at 55 ± 19 ka and the most recent eruption of Aluto has a radiocarbon age of 0.40 ± 0.05 cal. ka BP. During this post-caldera phase highly-evolved peralkaline rhyolite lavas, ignimbrites and pumice fall deposits have erupted from vents across the complex. Geochemical modelling is consistent with rhyolite genesis from protracted fractionation (> 80%) of basalt that is compositionally similar to rift-related basalts found east of the complex. Based on the style and volume of recent eruptions we suggest that silicic eruptions occur at an average rate of 1 per 1000 years, and that future eruptions of Aluto will involve explosive emplacement of localised pumice cones and effusive obsidian coulees of volumes in the range 1–100 × 106 m3

Intrusive equivalents of flood volcanics: evidence from petrology of xenoliths in Quaternary Tana basanites

The Injibara Quaternary basanites enclose a variety of xenoliths spanning in composition from peridotite through pyroxenite and gabbro to granite. This study focuses on the pyroxenite, gabbro and granite xenoliths. The pyroxenite xenoliths (enstatite + diopside + olivine ± spinel ± plagioclase ± ilmenite ± paragasite) are diverse, including olivine-orthopyroxenite, olivine-clinopyroxenite and websterite. They represent a suite of crystal cumulates from basalts with tholeiitic affinity evolving by polybaric crystal fractionation processes, or alternatively they may be related to chemical diversification of parental magma. The gabbro xenoliths, containing widely varying modal proportions of plagioclase, augite, enstatite, olivine and ilmenite, appear to be fragments of cumulate plutonic rocks, fractionated from tholeiitic basalts at high-level. They often show reaction textures, with a vermicular intergrowth of smaller augite, plagioclase and a chemically complex opaque phase composition embedded in glass from orthopyroxene. The granitic xenoliths contain quartz and two distinct feldspars–a sodic plagioclase and a potassic alkali feldspar– coprecipitated from the melt; accompanying mafic minerals are hydrous biotite and muscovite. This suggests that such granite magmas crystallized under water-saturated condition (PH2O = 5 kbar). Keywords/phrases: Cumulate, Ethiopia, Injibara, tholeiitc basalt, xenolith SINET: Ethiopian Journal of Science Vol.26(2) 2003: 93-10

Structural controls on fluid pathways in an active rift system : a case study of the Aluto volcanic complex

Hutchison was funded by NERC studentship NE/J5000045/1.In volcanically and seismically active rift systems, preexisting faults may control the rise and eruption of magma, and direct the flow of hydrothermal fluids and gas in the subsurface. Using high-resolution airborne imagery, field observations, and CO2 degassing data on Aluto, a typical young silicic volcano in the Main Ethiopian Rift, we explore how preexisting tectonic and volcanic structures control fluid pathways and spatial patterns of volcanism, hydrothermal alteration and degassing. A new light detection and ranging (lidar) digital elevation model and evidence from deep geothermal wells show that the Aluto volcanic complex is dissected by rift-related extensional faults with throws of 50-100 m. Mapping of volcanic vent distributions reveals a structural control by either rift-aligned faults or an elliptical caldera ring fracture. Soil-gas CO2 degassing surveys show elevated fluxes (>>100 g m-2 d-1) along major faults and volcanic structures, but significant variations in CO2 flux along the fault zones reflect differences in near-surface permeability caused by changes in topography and surface lithology. The CO2 emission from an active geothermal area adjacent to the major fault scarp of Aluto amounted to similar to 60 t d-1; we estimate the total CO2 emission from Aluto to be 250-500 t d-1. Preexisting volcanic and tectonic structures have played a key role in the development of the Aluto volcanic complex and continue to facilitate the expulsion of gases and geothermal fluids. This case study emphasizes the importance of structural mapping on active rift volcanoes to understand the geothermal field as well as potential volcanic hazards.Publisher PDFPeer reviewe

Constraining magma storage conditions at a restless volcano in the Main Ethiopian Rift using phase equilibria models

This work is a contribution to the Natural Environment Research Council (NERC) funded RiftVolc project (NE/L013932/1, Rift volcanism: past, present, and future). W.H., T.A.M., and D.M.P. are supported by and contribute to the NERC Centre for the Observation and Modelling of Earthquakes, Volcanoes, and Tectonics (COMET). W.H. M.J.S. were supported by a NERC studentships NE/J5000045/1 and NE/K500811/01 respectively.The Main Ethiopian Rift hosts a number of peralkaline volcanic centres, with many showing signs of recent unrest. Due, in part, to the low number of historical eruptions recorded in the region, volcanism in the Main Ethiopian Rift remains understudied relative to other volcanic settings and conditions of magma storage remain almost entirely unknown. Aluto is one of these restless caldera systems and identifying magma storage conditions is vital for evaluating the risks posed by recent periods of unrest. In this study, we ran ~ 150 fractional crystallisation models, using the Rhyolite-MELTS thermodynamic software, within the range P = 50–300 MPa, starting H2O = 0.5–3 wt% and fO2 = QFM-2 − QFM + 1. This represents a realistic range of potential magma storage conditions at Aluto. We assessed the fractionation trends produced using two different starting compositions, which represent different estimates of the parental melt feeding the system. The predicted liquid lines of descent produced by these models are compared with Aluto whole-rock data from the literature, and are presented along with new observations of the natural phase assemblage and erupted mineral compositions to provide information on the magma storage conditions. Using a new, quantitative statistical approach to compare empirical data and thermodynamic model-outputs, we find that the compositions of evolved peralkaline rhyolites from Aluto are best reproduced by isobaric fractional crystallisation from a rift-related basaltic composition, without the need for significant crustal assimilation. Around 90% protracted fractional crystallisation is required to produce these compositions. This indicates that the magmatic system is likely to exist as a highly crystalline mush. The best agreement between models and natural samples is at low pressures (150 MPa), low initial H2O concentrations (0.5 wt%) and relatively high oxygen fugacity (QFM). The depth of magma storage derived from these results (~ 5.6 ± 1 km) agrees well with the source depths modelled from measured ground deformation at Aluto in 2008. Data from other peralkaline volcanic centres in the Main Ethiopian Rift, such as Boset and Gedemsa, and at other locations globally (e.g. Pantelleria, Italy) suggest that these storage conditions are a common feature of many peralkaline volcanic centres. Our data is consistent with the formation of a Daly Gap at Aluto due to compositional stratification of the magma reservoir beneath the caldera, and the non-linear relationship between temperature and SiO2 concentration during magmatic differentiation.PostprintPeer reviewe