Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (42)

Search Parameters:
Keywords = East African Rift

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
22 pages, 824 KB  
Article
Success Conditions for Sustainable Geothermal Power Development in East Africa: Lessons Learned
by Helgi Thor Ingason and Thordur Vikingur Fridgeirsson
Sustainability 2026, 18(3), 1185; https://doi.org/10.3390/su18031185 - 24 Jan 2026
Viewed by 132
Abstract
Geothermal energy is a crucial component of climate adaptation and sustainability transitions, as it provides a dependable, low-carbon source of baseload power that can accelerate sustainable energy transitions and enhance climate resilience. Yet, in East Africa—one of the world’s most promising geothermal regions, [...] Read more.
Geothermal energy is a crucial component of climate adaptation and sustainability transitions, as it provides a dependable, low-carbon source of baseload power that can accelerate sustainable energy transitions and enhance climate resilience. Yet, in East Africa—one of the world’s most promising geothermal regions, with the East African Rift—a unique climate-energy opportunity zone—the harnessing of geothermal power remains slow and uneven. This study examines the contextual conditions that facilitate the successful and sustainable development of geothermal power in the region. Drawing on semi-structured interviews with 17 experienced professionals who have worked extensively on geothermal projects across East Africa, the analysis identifies how technical, institutional, managerial, and relational circumstances interact to shape outcomes. The findings indicate an interdependent configuration of success conditions, with structural, institutional, managerial, and meta-conditions jointly influencing project trajectories rather than operating in isolation. The most frequently emphasised enablers were resource confirmation and technical design, leadership and team competence, long-term stakeholder commitment, professional project management and control, and collaboration across institutions and communities. A co-occurrence analysis reinforces these insights by showing strong patterns of overlap between core domains—particularly between structural and managerial factors and between managerial and meta-conditions, highlighting the mediating role of managerial capability in translating contextual conditions into operational performance. Together, these interrelated circumstances form a system in which structural and institutional foundations create the enabling context, managerial capabilities operationalise this context under uncertainty, and meta-conditions sustain cooperation, learning, and adaptation over time. The study contributes to sustainability research by providing a context-sensitive interpretation of how project success conditions manifest in geothermal development under climate transition pressures, and it offers practical guidance for policymakers and partners working to advance SDG 7 (Affordable and Clean Energy), SDG 9 (Industry, Innovation and Infrastructure), and SDG 13 (Climate Action) in Africa. Full article
Show Figures

Figure 1

27 pages, 421 KB  
Review
A Synthesis of Environmental Policies and Identification of Critical Gaps in Critical Zones of South and East Africa
by Lwando Mdleleni, Kwanele Qonono, Konosoang Sobane, Wilfred Lunga, Mmakotsedi Magampa, Abongile Pindo, Caiphus Baloyi, Irene Koko and Christine Noe
Environments 2025, 12(9), 326; https://doi.org/10.3390/environments12090326 - 15 Sep 2025
Cited by 1 | Viewed by 1518
Abstract
Africa’s Critical Zones experience unprecedented environmental degradation but do not have effective governance modalities for policy implementation coordination across jurisdictional and stakeholder scales. This study addresses three specific scientific challenges: (1) How does policy discordance between national environmental policies and local implementation cultures [...] Read more.
Africa’s Critical Zones experience unprecedented environmental degradation but do not have effective governance modalities for policy implementation coordination across jurisdictional and stakeholder scales. This study addresses three specific scientific challenges: (1) How does policy discordance between national environmental policies and local implementation cultures undermine conservation effectiveness in Critical Zones? (2) What do power asymmetries among stakeholders contribute to governance failure? (3) To what extent do implementation gaps stem from the exclusion of Indigenous knowledge systems from mainstream policy-making processes? In this qualitative multi-case study, the research examines policy reports, technical reports, and interviews with important stakeholders in five African Critical Zones: Central Rift Valley (Ethiopia), Kilombero Valley (Tanzania), Maligunde Dam (Malawi), Lake Chivero (Zimbabwe), and Muizenberg East (South Africa). Evidence shows that shattered institutional imperatives create policy gaps exploited by industrial stakeholders, where policy design from the top down routinely leaves in place established community-based systems of governance that have historically maintained these ecosystems in equilibrium. Excess power held by government ministries compared to local communities results in 73% of environmental policy being enforced with ineffective stakeholder engagement, with non-compliance levels across examined locations exceeding 60%. The study attests to the fact that co-management incorporated governance systems that adopt traditional ecological knowledge systems register 40% greater compliance rates with policies. These findings are empirical evidence of adaptive governance models that can bridge Africa’s most vulnerable ecosystems’ policy–practice gap, and they guide direct implementation of the African Union Agenda 2063 environmental targets. Full article
Show Figures

Figure 1

18 pages, 6291 KB  
Article
Petrological Exploration of Magma Storage and Evolution Conditions at the Eastern Virunga Volcanic Province (Rwanda, East African Rift System)
by Fabio Colle, Teresa Trua, Serena Giacomelli, Massimo D’Orazio and Roberto Valentino
Minerals 2025, 15(7), 666; https://doi.org/10.3390/min15070666 - 20 Jun 2025
Cited by 1 | Viewed by 813
Abstract
The Virunga Volcanic Province (VVP), located in the western branch of the East African Rift System, hosts a variety of alkaline lavas erupted from closely spaced volcanic centers. However, the magmatic system of this region, particularly in its eastern sector, remains insufficiently constrained. [...] Read more.
The Virunga Volcanic Province (VVP), located in the western branch of the East African Rift System, hosts a variety of alkaline lavas erupted from closely spaced volcanic centers. However, the magmatic system of this region, particularly in its eastern sector, remains insufficiently constrained. In this study, we present a petrological and geochemical investigation of basaltic to trachytic lavas from the eastern VVP. Thermobarometric analysis of mineral phases indicates that basalts originated from magma storage zones between 4 and 30 km deep, with crystallization temperatures of ~1200 °C and melt H2O contents lower than 1 wt%. In contrast, more evolved magmas crystallized at similar depths, but at lower temperatures (~1050 °C) and higher H2O contents, ranging from 2 to 4 wt%. Thermodynamic modelling suggests that extensive (up to 70%) fractional crystallization of an assemblage dominated by olivine, clinopyroxene, and plagioclase can produce the more evolved trachytic derivatives from basaltic parental melts. When integrated with previous studies from other VVP volcanoes, our findings deepen the understanding of the architecture of the magmatic system beneath the region, suggesting it resembles a well-developed multi-level plumbing system. Full article
Show Figures

Figure 1

12 pages, 3418 KB  
Article
Returners and New Arrivals After the Crash: Intermediate Hosts and Global Invaders Dominate Gastropod Fauna of Lake Naivasha, Kenya
by Christian Albrecht, John Kochey Kipyegon, Annett Junginger and Catharina Clewing
Diversity 2025, 17(4), 265; https://doi.org/10.3390/d17040265 - 9 Apr 2025
Cited by 1 | Viewed by 2320
Abstract
Aquatic alien species (AAS) have had a major impact on freshwater ecosystems, including Lake Naivasha in Kenya. Here, the ecosystem has undergone tremendous changes and multiple species introductions over the past 100 years, and molluscs have experienced a major decline in species diversity. [...] Read more.
Aquatic alien species (AAS) have had a major impact on freshwater ecosystems, including Lake Naivasha in Kenya. Here, the ecosystem has undergone tremendous changes and multiple species introductions over the past 100 years, and molluscs have experienced a major decline in species diversity. The East African Rift Lakes have experienced a steady rise in lake levels since 2010. We investigated the impact of recent ecosystem changes on the lakes’ molluscs by determining the current mollusc diversity and its composition. We also reconstruct the history of faunal change and turnover over the last 100 years and discuss the future of molluscs in the lake and the implications in a One Health context. The combined effects of rising water levels and the decline of the crayfish Procambarus clarkii are likely to be responsible for the resurgence of Lake Naivasha’s mollusc fauna. The current fauna consists of three global invaders of American origin, one of which is new to East Africa (Pseudosuccinea columella) and another of which has only recently begun to spread (Pomacea canaliculata). A further three species are native to Africa, two of which are known from historical records, while one is new to Lake Naivasha (Bulinus forskalii). All native species are of public health (Biomphalaria sudanica) and veterinary health (Bulinus tropicus, Bulinus forskalii) concern. The current biodiversity of molluscs has reached the same level as in historical times, but the species composition is remarkably different. Full article
(This article belongs to the Special Issue Advances in Freshwater Mollusk Research)
Show Figures

Graphical abstract

32 pages, 8172 KB  
Article
Tectono-Stratigraphic Framework and Hydrocarbon Potential in the Albert Rift, Uganda: Insights from Basin and Petroleum System Modeling
by Lauben Twinomujuni, Keyu Liu, Hafiz Ahmed Raza Hassan, Kun Jia, Shunyu Wang, Tonny Sserubiri and Mathias Summer
Appl. Sci. 2025, 15(6), 3130; https://doi.org/10.3390/app15063130 - 13 Mar 2025
Viewed by 2315
Abstract
The Albert Rift in Uganda is a significant geological and petroleum exploration frontier within the East African Rift System. The basin has been comprehensively analyzed thorough the means of literature survey, seismic data analysis, well-log interpretation, and basin and petroleum systems modeling to [...] Read more.
The Albert Rift in Uganda is a significant geological and petroleum exploration frontier within the East African Rift System. The basin has been comprehensively analyzed thorough the means of literature survey, seismic data analysis, well-log interpretation, and basin and petroleum systems modeling to examine the complex interactions of tectonics, sedimentation, and hydrocarbon generation and expulsion within the rift basin. Our findings reveal a detailed tectonostratigraphic framework with multiple Neogene to Quaternary depositional sequences and structural features influencing hydrocarbon maturation, generation, and expulsion. Key stratigraphic units are identified, highlighting their contributions to a viable petroleum system present within the basin. The Albert Rift is a Neogene petroleum system that is currently generating and expelling hydrocarbons to various potential traps. Mid-Miocene sediments were deposited in a favorable lacustrine environment as a viable source rock, which began generating and expelling hydrocarbons from the Middle to Late Pliocene in the deeper parts of the rift basin, while those deposits in shallower areas have only recently entered the oil window and have yet to start major petroleum generation. Full article
(This article belongs to the Section Energy Science and Technology)
Show Figures

Figure 1

23 pages, 4802 KB  
Review
Stromatolites and Their “Kin” as Living Microbialites in Contemporary Settings Linked to a Long Fossil Record
by Ed Landing and Markes E. Johnson
J. Mar. Sci. Eng. 2024, 12(12), 2127; https://doi.org/10.3390/jmse12122127 - 22 Nov 2024
Cited by 2 | Viewed by 5626
Abstract
Organo-sedimentary deposits that result from fine-grained sediment trapping, binding, and likely precipitation (of carbonate) by microbes in flat-mat, branching, and dome-shaped constructions are termed microbialites. They were first identified as stromatolites by paleontologists well before the discovery of cyanobacteria that build the same [...] Read more.
Organo-sedimentary deposits that result from fine-grained sediment trapping, binding, and likely precipitation (of carbonate) by microbes in flat-mat, branching, and dome-shaped constructions are termed microbialites. They were first identified as stromatolites by paleontologists well before the discovery of cyanobacteria that build the same kinds of structures in contemporary settings around the world. Earth’s earliest life forms were prokaryotes (bacteria and bacteria-like forms) that reproduced under anaerobic conditions and later produced increasingly aerobic conditions. Stromatolites persisted through later Archean and Proterozoic times through the subsequent Phanerozoic to the present. At the start of the Cambrian Period 538 million years ago, stromatolites continued alongside rapidly diversifying plant and animal phyla during the Cambrian explosion of eukaryotic life, which have complex cells with internal structures and tissue-grade organization in multicellular taxa. The type locality exhibiting clear examples of stromatolite structures is conserved at Lester Park near Saratoga Springs in northeastern New York State. Paleontologist James Hall (1811–1898) was the first in 1884 to assign a Latin binomen (Cryptozoon proliferum) to stromatolite fossils from Lester Park. Thereafter, reports on formally named stromatolites proliferated, as did examples from virtually all subsequent geological time intervals including the Pleistocene Epoch. However, recognition that living cyanobacteria formed stromatolites identified as Cryptozoon took place much later in 1961 with the announcement by geologist Brian W. Logan (1933–2008) who described modern constructions in Hamlin Pool, Shark Bay, Western Australia. Initially, Shark Bay was regarded as a one-of-a-kind sanctuary for stromatolites living under restricted conditions with elevated levels of salinity that prohibited competition or grazing by eukaryotes. Most notably, among other settings with living stromatolites discovered and described since then are the Bahamas, East African rift lakes, Mexico’s Baja California, and saline lakes in Argentina. This report reviews the history of discoveries of modern-day stromatolites, more commonly called microbialites by biologists. All are predicated on the ground-breaking efforts of geologists and paleontologists who first described fossil stromatolites but were unaware of their living counterparts. The Lester Park locality is highlighted together with a master list of other North American localities that feature purported Cryptozoons. Full article
(This article belongs to the Special Issue Feature Review Papers in Geological Oceanography)
Show Figures

Graphical abstract

24 pages, 12335 KB  
Article
Evolution of Resilience Spatiotemporal Patterns and Spatial Correlation Networks in African Regional Economies
by Daliang Jiang, Wanyi Zhu and Zhenke Zhang
Land 2024, 13(9), 1537; https://doi.org/10.3390/land13091537 - 23 Sep 2024
Cited by 1 | Viewed by 1706
Abstract
This paper comprehensively utilizes the entropy-TOPSIS method, Lyapunov index, and kernel density estimation to measure the spatiotemporal evolution characteristics of regional economic resilience in 52 African countries (regions) from 2008 to 2019. It also examines the spatial network characteristics of regional economic resilience [...] Read more.
This paper comprehensively utilizes the entropy-TOPSIS method, Lyapunov index, and kernel density estimation to measure the spatiotemporal evolution characteristics of regional economic resilience in 52 African countries (regions) from 2008 to 2019. It also examines the spatial network characteristics of regional economic resilience in each country (region) through gravity models and social network analysis. The findings reveal that: (1) Although the resilience of African regional economies fluctuates, it generally shows an improving trend. Traditional economic powers and regional giants such as Libya, Nigeria, South Africa, Egypt, Morocco, and Tunisia demonstrate outstanding performance in economic resilience. (2) In terms of scale resilience, the countries along the North African Mediterranean coast exhibit particularly prominent advantages. However, the overall performance of Africa in fiscal resilience and openness resilience tends to be weak. Industrial resilience is influenced by colonial legacies and tends to stabilize. (3) The differences in economic resilience values and the fluctuation trajectories of economic resilience levels converge. North African economies exhibit resilience far higher than the mean and other regions, while East, West, and Central Africa consistently perform below the mean in the long term. Southern Africa’s gap from the mean is relatively small, leading to a stalemate. The fluctuation amplitude of differences within each region varies. (4) The overall level of resilience in African regional economies has steadily improved, displaying a trend of polarization. There is evident spatial polarization in West Africa, with Southern Africa demonstrating a trend of multipolarity transitioning towards bipolarity. Conversely, North Africa strengthens its features of bipolar differentiation, while East and Central Africa exhibit tendencies towards multipolarity. (5) Despite some fluctuations in the spatial network of regional economic resilience around 2016, connections among African countries have become increasingly tight, gradually forming three major spatial correlation network clusters: the North African Mediterranean coast, the West–Central African Pan-Gulf of Guinea region, and the East–South African Rift Valley region. Nigeria holds a prominent position as a regional core. Zambia, Cameroon, and the Central African Republic have played certain regional core roles at different times. Nigeria and South Africa also demonstrate significant intermediary roles, while Zambia, Cameroon, and Burkina Faso act as bridges in different periods of network connections. Based on the characteristics of spatial correlation networks, African regions gradually form four major cohesive subgroups and eight sub-subgroups. Full article
Show Figures

Figure 1

20 pages, 11131 KB  
Article
Soil-Forming Factors of High-Elevation Mountains along the East African Rift Valley: The Case of the Mount Guna Volcano, Ethiopia
by Mekonnen Getahun Sisay, Enyew Adgo Tsegaye, Alemayehu Regassa Tolossa, Jan Nyssen, Amaury Frankl, Eric Van Ranst and Stefaan Dondeyne
Soil Syst. 2024, 8(2), 38; https://doi.org/10.3390/soilsystems8020038 - 24 Mar 2024
Cited by 12 | Viewed by 4831
Abstract
The soils of the high-elevation mountains along the East African Rift Valley are poorly understood. Assessing the potential of soils for agriculture, climate change mitigation, and environmental functioning requires insight into how they relate to the factors influencing soil formation. Between 3000 and [...] Read more.
The soils of the high-elevation mountains along the East African Rift Valley are poorly understood. Assessing the potential of soils for agriculture, climate change mitigation, and environmental functioning requires insight into how they relate to the factors influencing soil formation. Between 3000 and 4120 m a.s.l., 85 soil profiles of Mount Guna were described and sampled. Standard physicochemical analyses were done on all pedons. Additionally, X-ray diffraction, Alox and Feox content, and P fixation were performed on six selected profiles. Soils on Mount Guna included Andosols, Phaeozems, Leptosols, Regosols, Cambisols, Luvisols, and Vertisols. With increasing elevation, clay content, bulk density, and pH decreased while the C:N ratio remained constant. In contrast, sand, silt, silt-to-clay ratio, SOC, Ntotal, and SOCS increased. With a factor analysis, the soil-forming factors’ elevation/climate could be disentangled from the factor’s parent material as these affect topsoil and subsoil differently. In the ordination based on climate/elevation and parent material, Andosols and Vertisols stood out while other Reference Soil Groups (RSG) showed indistinct patterns. Soil erosion appeared as an additional soil-forming factor not accounted for by the factor analysis. The distribution of the RSG was significantly associated with elevation belts (p < 0.001), lithology (p < 0.001), and landcover (p < 0.003). On the summital ridge, the Andosols were crucial for groundwater storage due to high precipitation. Shallow and stony soils in the mid-elevation belt contributed to runoff generation. Average soil carbon stock ranged from 8.1 to 11 kg C m−2 in the topsoil and from 29.2 to 31.9 kg C m−2 in the upper meter, emphasizing the global importance of high-elevation areas for carbon sequestration. Full article
Show Figures

Figure 1

12 pages, 16510 KB  
Article
An Autonomous Thermal Camera System for Monitoring Fumarole Activity
by Harald van der Werff, Eunice Bonyo and Christoph Hecker
Sensors 2024, 24(6), 1999; https://doi.org/10.3390/s24061999 - 21 Mar 2024
Cited by 1 | Viewed by 1761
Abstract
The Kenyan part of the East African Rift System hosts several geothermal fields for energy production. Changes in the extraction rate of geothermal fluids and the amount of water re-injected into the system affect reservoir pressure and production capacity over time. Understanding the [...] Read more.
The Kenyan part of the East African Rift System hosts several geothermal fields for energy production. Changes in the extraction rate of geothermal fluids and the amount of water re-injected into the system affect reservoir pressure and production capacity over time. Understanding the balance of production, natural processes and the response of the geothermal system requires long-term monitoring. The presence of a geothermal system at depth is often accompanied by surface manifestations, such as hot water springs and fumaroles, which have the potential for monitoring subsurface activity. Two thermal camera timelapse systems were developed and installed as part of a multi-sensor observatory in Kenya to capture fumarole activity over time. These cameras are an aggregation of a camera unit, a control unit, and a battery charged by a solar panel, and they monitor fumarole activity on an hourly basis, with a deep sleep of the system in between recordings. The article describes the choice of hardware and software, presents the data that the cameras acquire, and discusses the system’s performance and possible improvement points. Full article
(This article belongs to the Section Remote Sensors)
Show Figures

Figure 1

27 pages, 13685 KB  
Article
Using an Open-Source Tool to Develop a Three-Dimensional Hydrogeologic Framework of the Kobo Valley, Ethiopia
by Sisay S. Mekonen, Scott E. Boyce, Abdella K. Mohammed and Markus Disse
Geosciences 2024, 14(1), 3; https://doi.org/10.3390/geosciences14010003 - 20 Dec 2023
Cited by 2 | Viewed by 4093
Abstract
Groundwater resource management requires understanding the groundwater basin’s hydrogeology and would be improved with the development of a three-dimensional hydrogeologic framework model (HFM). A wide range of methods and software exist to quantify the extent, structure, and properties of geologic systems. However, most [...] Read more.
Groundwater resource management requires understanding the groundwater basin’s hydrogeology and would be improved with the development of a three-dimensional hydrogeologic framework model (HFM). A wide range of methods and software exist to quantify the extent, structure, and properties of geologic systems. However, most geologic software is proprietary and cost-prohibitive for use in developing countries. GemPy is a Python-based, open-source (no-cost) tool for generating three-dimensional geological models. This study uses available data and GemPy to develop the Kobo Valley Hydrogeologic Framework Model (KV-HFM), a three-dimensional HFM for Kobo Valley in northern Ethiopia, which is part of the East African Rift System. The KV-HFM is a conceptual model that comprises the hydrostratigraphy, structural features, and hydraulic properties of the Kobo Valley groundwater system. The limited data described the extent and altitude of the hydrostratigraphic units using the GemPy implicit potential–field interpolation. The KV-HFM showed the existence of an east-to-west, structural-based groundwater divide composed of volcanic rock and clay. This divide splits the catchment into two groundwater systems with limited interconnected flow. This study illustrates the use of open-source software for developing an HFM using sparse, existing geologic data. Full article
Show Figures

Figure 1

53 pages, 8761 KB  
Article
Marker Minerals in Volcanics and Xenoliths—An Approach to Categorize the Inferred Magmatic Rocks Underneath the Present-Day Volcanic Landscape of Tenerife, Spain (NW African Rare Mineral Province)
by Harald Gerold Dill and Kurt Anton Rüsenberg
Minerals 2023, 13(11), 1410; https://doi.org/10.3390/min13111410 - 3 Nov 2023
Cited by 5 | Viewed by 7008
Abstract
A mineralogical mapping (terrain analysis) based on micro-mounts has been performed in the Archipelago of the Canary Islands, Spain. The rare elements Be, F, Li, Nb, Ta, Zr, Hf, and rare earth elements (REE) were investigated on the largest island of the Canary [...] Read more.
A mineralogical mapping (terrain analysis) based on micro-mounts has been performed in the Archipelago of the Canary Islands, Spain. The rare elements Be, F, Li, Nb, Ta, Zr, Hf, and rare earth elements (REE) were investigated on the largest island of the Canary Islands Archipelago, Tenerife, Spain. This study forms a contribution to the metallogenetic evolution of the offshore area of the NW African Rare Mineral Province. The finds made at Tenerife were correlated by means of minero-stratigraphy with the adjacent islands La Gomera, Gran Canaria and Fuerteventura, where typical critical element host rocks, e.g., carbonatites, are exposed. At Tenerife, these hidden rock types are only indicated by a wealth of 128 compositional first-order marker minerals hosting Be, F, Zr, Nb, Ta, Zr, Hf, Li, Cs, Sn, W, Ti and REE plus Y and another 106 structural second-order marker minerals describing the geodynamic and morpho-structural evolution of Tenerife (Mn, Fe, Pb, U, Th, As, Sb, V, S, B, Cu, Zn, Mo, Au). Based upon the quantitative micro-mineralogical mapping of lithoclasts and mineralogical xenoliths (foid-bearing monzodiorite/gabbro, (nepheline) syenite, phonolite trachyte) in volcanic and volcaniclastic rocks, hidden intrusive/subvolcanic bodies can be delineated that are associated with contact-metasomatic, zeolitic and argillic alteration zones, as well as potential ore zones. Two potential types of deposits are determined. These are pegmatite-syenites with minor carbonatites bound to a series of agpaitic intrusive rocks that are genetically interlocked with rift zones and associated with a hotspot along a passive continental margin. Towards the east, the carbonatite/alkali magmatite ratio reverses at Fuerteventura in favor of carbonatites, while at Gran Canaria and La Gomera, shallow hypogene/supergene mineral associations interpreted as a marginal facies to Tenerife occur and a new REE discovery in APS minerals has been made. There are seven mineralizing processes different from each other and representative of a peculiar metallogenic process (given in brackets): Protostage 1 (rifting), stages 2a to 2d (differentiation of syenite–pegmatite), stages 3 to 4b (contact-metasomatic/hydrothermal mineralization), stages 5a to 5b (hydrothermal remobilization and zeolitization), stage 6 (shallow hypogene-supergene transition and kaolinization), and stage 7 (auto-hydrothermal-topomineralic mineralization). The prerequisites to successfully take this holistic approach in economic geology are a low maturity of the landscapes in the target area, a Cenozoic age of endogenous and exogenous processes amenable to sedimentological, geomorphological, volcano-tectonic and quantitative mineralogical investigations. The volcanic island’s mineralogical mapping is not primarily designed as a proper pre-well-site study on the Isle of Tenerife, but considered a reference study area for minero-stratigraphic inter-island correlation (land–land) and land–sea when investigating the seabed and seamounts around volcanic archipelagos along the passive margin, as exemplified by the NW African Craton and its metallogenic province. This unconventional exploration technique should also be tested for hotspot- and rift-related volcanic islands elsewhere on the globe for mineral commodities different from the ones under study. Full article
Show Figures

Figure 1

21 pages, 5946 KB  
Article
A New and Automated Method for Improving Georeferencing in Nighttime Thermal ECOSTRESS Imagery
by Agnieszka Soszynska, Harald van der Werff, Jan Hieronymus and Christoph Hecker
Sensors 2023, 23(11), 5079; https://doi.org/10.3390/s23115079 - 25 May 2023
Cited by 3 | Viewed by 2595
Abstract
Georeferencing accuracy plays a crucial role in providing high-quality ready-to-use remote sensing data. The georeferencing of nighttime thermal satellite imagery conducted by matching to a basemap is challenging due to the complexity of thermal radiation patterns in the diurnal cycle and the coarse [...] Read more.
Georeferencing accuracy plays a crucial role in providing high-quality ready-to-use remote sensing data. The georeferencing of nighttime thermal satellite imagery conducted by matching to a basemap is challenging due to the complexity of thermal radiation patterns in the diurnal cycle and the coarse resolution of thermal sensors in comparison to sensors used for imaging in the visual spectral range (which is typically used for creating basemaps). The presented paper introduces a novel approach for the improvement of the georeferencing of nighttime thermal ECOSTRESS imagery: an up-to-date reference is created for each to-be-georeferenced image, derived from land cover classification products. In the proposed method, edges of water bodies are used as matching objects, since water bodies exhibit a relatively high contrast with adjacent areas in nighttime thermal infrared imagery. The method was tested on imagery of the East African Rift and validated using manually set ground control check points. The results show that the proposed method improves the existing georeferencing of the tested ECOSTRESS images by 12.0 pixels on average. The strongest source of uncertainty for the proposed method is the accuracy of cloud masks because cloud edges can be mistaken for water body edges and included in fitting transformation parameters. The georeferencing improvement method is based on the physical properties of radiation for land masses and water bodies, which makes it potentially globally applicable, and is feasible to use with nighttime thermal infrared data from different sensors. Full article
(This article belongs to the Section Environmental Sensing)
Show Figures

Figure 1

18 pages, 7918 KB  
Article
Numerical Investigation on the Dynamic Response of Fault-Crossing Tunnels under Strike-Slip Fault Creep-Slip and Subsequent Seismic Shaking
by Shuquan Peng, Yuankai Zeng, Ling Fan, Guobo Wang, Zhize Xun and Guoliang Chen
Buildings 2023, 13(5), 1163; https://doi.org/10.3390/buildings13051163 - 27 Apr 2023
Cited by 10 | Viewed by 2443
Abstract
Tunnels built in geologically active areas are prone to severe damage due to fault dislocation and subsequent earthquakes. Using the Ngong tunnel in the East African Rift Valley as an example, the dynamic response of a fault-crossing tunnel and the corresponding sensitivity are [...] Read more.
Tunnels built in geologically active areas are prone to severe damage due to fault dislocation and subsequent earthquakes. Using the Ngong tunnel in the East African Rift Valley as an example, the dynamic response of a fault-crossing tunnel and the corresponding sensitivity are numerically simulated by considering four factors, i.e., tunnel joint stiffness, isolation layer elastic modulus, strike-slip fault creep-slip and earthquakes. The results show that a valley-shaped propagation of peak displacement at the tunnel invert occurs in the longitudinal axis direction under an earthquake alone. Then, it transforms into an S-shaped under strike-slip fault creep-slip and subsequent seismic shaking. The tunnel invert in the fault zone is susceptible to tensile and shear failures under strike-slip fault creep-slip movements of less than 15 cm and subsequent seismic shaking. Furthermore, the peak tensile and shear stress responses of the tunnel invert in the fault zone are more sensitive to fault creep-slip than earthquakes. They are also more sensitive to the isolation layer elastic modulus compared to the joint stiffness of a segmental tunnel with two segments. The stress responses can be effectively reduced when the isolation layer elastic modulus logarithmic ratio equals −4. Therefore, the isolation layer is more suitable to mitigate the potential failure under small strike-slip fault creep-slip and subsequent seismic shaking than segmental tunnels with two segments. The results of this study can provide some reference for the disaster mitigation of fault-crossing tunnels in terms of dynamic damage in active fault zones. Full article
(This article belongs to the Special Issue Advanced Seismic Technologies in Underground Structures)
Show Figures

Figure 1

16 pages, 3439 KB  
Review
Geothermal Play Types along the East Africa Rift System: Examples from Ethiopia, Kenya and Tanzania
by Claudio Pasqua, Paolo Chiozzi and Massimo Verdoya
Energies 2023, 16(4), 1656; https://doi.org/10.3390/en16041656 - 7 Feb 2023
Cited by 10 | Viewed by 4309
Abstract
Based on geophysical, geological and geochemical investigations carried out in the last decade, we reviewed three major geothermal plays that well represent the different structural, volcanological and hydrogeological realms that can be encountered in the East African Rift System (EARS). Alalobeda (Ethiopia) and [...] Read more.
Based on geophysical, geological and geochemical investigations carried out in the last decade, we reviewed three major geothermal plays that well represent the different structural, volcanological and hydrogeological realms that can be encountered in the East African Rift System (EARS). Alalobeda (Ethiopia) and Menengai (Kenya) are examples of typical geothermal plays of the Eastern Branch of EARS. The former is a fault-leakage-controlled geothermal play located in a graben structure. The heat source is likely deep-seated, widespread magmatism, associated with the lithosphere thinning that regionally affects this area. The reservoir temperature of the water-dominated system ranges from 185 to 225 °C. Menengai can be classified as a convection-dominated magmatic play type. The heat source could be a magmatic intrusion located beneath a caldera. A shallow, liquid-dominated reservoir (with temperatures of 150–190 °C) and an intermediate-deep reservoir, hosting steam and liquid (with temperatures of 230–340 °C), were detected. The Kilambo-Ilwalilo play (Tanzania) is an example of geothermal play of the Western Branch of EARS. It is in a half-graben realm where a regional fault controls the ascending groundwater flow. Reservoir temperatures are about 110–140 °C, and the heat source is provided by lithosphere thinning. The results of this study provide helpful guidelines for future studies on the geothermal resources in the rift. Full article
(This article belongs to the Section H2: Geothermal)
Show Figures

Figure 1

12 pages, 2276 KB  
Article
Geochemical Characterization of Nyamyumba Hot Springs, Northwest Rwanda
by Francois Hategekimana, Theophile Mugerwa, Cedrick Nsengiyumva, Fils Vainqueur Byiringiro and Digne Edmond Rwabuhungu Rwatangabo
AppliedChem 2022, 2(4), 247-258; https://doi.org/10.3390/appliedchem2040017 - 13 Dec 2022
Cited by 2 | Viewed by 4219
Abstract
A hot spring is a hot water source that naturally occurs on the surface of the Earth from underground; it is typically heated by subterranean volcanic activity and the local underground geothermal gradient. There are four main hot springs in Rwanda, such as: [...] Read more.
A hot spring is a hot water source that naturally occurs on the surface of the Earth from underground; it is typically heated by subterranean volcanic activity and the local underground geothermal gradient. There are four main hot springs in Rwanda, such as: Kalisimbi, Bugarama, Kinigi, and Nyamyumba, formerly named Gisenyi hot springs. It is often believed that soaking in a hot spring is a great way to naturally detox human skin. This research focuses on the geochemical analysis of Nyamyumba hot springs, located near the fresh water supply of Lake Kivu, with the purpose of understanding its healing capacity and safety. The Nyamyumba hot springs are located in the western branch of the East African Rift System, near the Virunga volcanic complex, which explains the rising and heating mechanism of the water. The concentrations of sulfate, iron, ammonia, silica, and phosphate, and the conductivity, alkalinity, and salinity of the water were measured using standard procedures. The results showed that the hot spring water has higher concentrations of chemicals compared to the Lake Kivu water, and the geochemistry of these hot springs may be associated with rock dissolution by hot water. The measured parameters were compared with World Health Organization (WHO) standards for recreational waters, and it has been identified that the Nyamyumba hot springs are safe to use for swimming and therapeutic activities. Full article
(This article belongs to the Special Issue Feature Papers in AppliedChem)
Show Figures

Figure 1

Back to TopTop