Earth Science Malaysia (ESMY)

A 2D geo-electric survey was carried out over parts of the study area to ascertain the presence of hydrated aluminum silicate minerals. This study used Dipro software and other techniques developed during the study to assess the accuracy of the pole configuration in defining mineral zones. The IP data revealed a number of subsurface zones with high real component current density which define the potential subsurface structural features (fractures/ faults zones) with possible kaolinite zone. The results from the geo-electric imaging models reveal a heterogeneous nature of mineralisation within zone of high resistivity (low conductivity) that may represent kaolin bearing quartz, feldspar or mica. The 2D section of the kaolinated showed regions of both high and low conductivity with values that ranged from -100 to 74.9 Ω-1m-1 with structural trends in the NE-SW direction. The mineralized zones is characterized by fine particles size, plate like shape and chemical inertness.

This study applies three-dimensional (3D) electrical resistivity imaging (ERI), integrated with borehole log data, to investigate subsurface architecture and aquifer vulnerability at the University of Benin Teaching Hospital (UBTH) Football Field, Edo State, Nigeria. The site, situated within the hydro-geologically significant Benin Formation, revealed a stratified subsurface comprising six distinct layers. Borehole log correlation confirmed the identification of sandy strata between 10.0 m and 17.4 m as primary aquifer zones with high porosity and permeability, underlain by compacted sandstones and crystalline bedrock that serve as structural markers and natural hydraulic barriers. Vulnerability analysis using the GOD model classified the aquifer as moderately susceptible to contamination due to thin clay protective layers and increasing urbanisation pressures. This research underscores the novel application of 3D ERI alongside borehole data to enhance subsurface characterisation and aquifer delineation in complex urban terrains. The findings provide actionable insights for groundwater resource management and environmental protection, with recommendations for multi-method geophysical surveys and hydrogeological modelling to optimise resource utilisation and safeguard aquifers against contamination.

Urban flooding in Edo State, Nigeria, has intensified due to rapid urbanization, land use/land cover (LULC) change, and climatic variability. Identifying areas of exposure and vulnerability is critical for planning and risk reduction. This study employed Geographic Information Systems (GIS) and Remote Sensing (RS) to analyze Landsat imagery and classify LULC. Climate data (rainfall and temperature distribution) were integrated to map flood vulnerability across the study area. Flood risk zones were further delineated using spatial analysis of land cover, topography, and climatic factors. Landsat image classification identified five land cover types: built-up areas (14.58%), agricultural land (48.93%), bare ground (5.06%), water bodies (5.35%), and vegetation (26.08%). Results show that anthropogenic activities such as deforestation, agricultural expansion, and infrastructure development significantly alter LULC, heightening flood vulnerability, particularly in agricultural zones. Rainfall distribution showed that areas receiving 2100–2400 mm annually were highly vulnerable, 1600–2000 mm zones moderately vulnerable, and 1300–1500 mm zones low risk. Temperature mapping revealed high-temperature areas occupying 20.63% of the landscape, medium-temperature zones 33.97%, and low-temperature zones 45.40%. Flood risk assessment indicated that 4.78% of the area is at very low risk, 10.20% at low risk, 19.75% at moderate risk, 30.70% at high risk, and the largest share within very high risk. Flood-prone regions in Edo State are strongly influenced by topography, vegetation loss, soil compaction, and precipitation variability. The findings highlight the urgent need for climate-responsive urban policies, sustainable land management, and inclusive adaptation strategies to reduce the increasing threat of urban flooding in the state.

Sixteen Tethyan Lagenid foraminiferal species of the genus Hemirobulina are presented in the study. One species is believed to be new: Hemirobulina abuhanii. The identified Hemirobulina species mainly represent neritic-middle bathyal environmental conditions.

The study aims to mitigate the risks associated with operating in a borehole environment. Pore pressure predictions have been conducted using well log traces to identify porous lithological units and the onset of overpressure. The findings of the study indicate a lithology characterised by shaly/sandy structural distributions that significantly influence effective stresses. The top of overpressure for well X01 is located at a depth of 11,450 ft, while for well X02, it is at a depth of 11,801 ft. The forecast for fracture pressure is estimated to range from 9,394 psi for X01 to 9,760 psi for X02. This is substantiated by an estimated fracture pressure gradient of 0.82 psi/ft for well X01 and 0.83 psi/ft for well X02 across parts of the Niger Delta. The results from the assessment of overburden pressure indicate that the study area is over pressured.

The Iseyin-Ibadan Schist Belt in southwest Nigeria, part of the Nigerian Basement Complex, displays Barrovian-type metamorphism typical of the Dalradian Supergroup of the Scottish Highlands; this study investigated the metamorphic basement south of this schist belt where Dalradian metamorphism was first reported, analyzing mineralogical composition and geochemical characteristics of quartz mica schist and muscovite garnet schist through field mapping, petrographic analysis, and whole-rock geochemistry, revealing greenschist to amphibolite facies metamorphic grade with assemblages like phengite-bearing muscovite, biotite, and almandine garnet, showing subtle compositional differences but striking mineralogy, particularly in muscovite and garnet concentrations, while an average Al2O3/TiO2 value (41.30) indicated a granitic source for the metasediments, and geochemical signatures, including major oxides, suggested mixed provenance and moderate weathering intensity.

The process of urbanization has increasingly transformed landscapes, especially in rapidly developing cities like Hyderabad, which has witnessed considerable growth over the past two decades. This study investigates the spatio-temporal changes in land use and land cover (LULC) in Hyderabad city from 2000 to 2020 by utilizing multi-temporal satellite imagery and advanced geospatial techniques. The study aims to understand the extent, pattern, and nature of urban growth and its impact on other land categories such as vegetation, agricultural lands, and water bodies. Satellite data from Landsat missions (2000, 2010, and 2020) were classified using supervised image classification methods to derive LULC maps. A detailed change detection analysis was conducted to quantify the transitions among different land categories. The results reveal a significant expansion of built-up areas, especially along the peripheries and in the direction of the IT corridor and Outer Ring Road (ORR), indicating spatially uneven and corridor-based urban growth. Simultaneously, a sharp decline in vegetation and agricultural lands, along with the encroachment of water bodies, was observed. These findings underline the growing pressure on natural resources, increasing fragmentation of green spaces, and the degradation of ecological functions due to unplanned and rapid urban expansion. The study highlights the effectiveness of Remote Sensing and GIS tools in detecting, visualizing, and analyzing urban changes and advocates for their application in urban planning and management. The paper concludes by recommending sustainable development practices and the integration of geospatial monitoring in urban governance frameworks to ensure environmental sustainability and resilience in Hyderabad’s future urban growth.

The contamination of groundwater by hydrocarbons presents a significant challenge for the residents of the Kegbara Dere community in Ogoniland, Rivers State, Southern Nigeria. The area has been plagued by oil spillage, and the damage done to Ogoniland as a result of oil spillage is so massive that the United Nation (UN) did a report on the extent of pollution in the area. This study aimed to identify and characterize the extent of the groundwater system contamination in the study area. The electrical resistivity imaging and geochemical methods were adopted. 2D electrical resistivity imaging (ERI) along four (4) traverses was processed and analyzed to obtain resistivity-depth sections of the subsurface. Three unique geoelectric zones were delineated, with the intermediate zone identified as the contaminated aquiferous unit. This unit’s resistivity values ranged from 10,804 to 100,000 Ωm along line Lx3, 324 to 23,497 Ωm along line Lx5, 1019 to 10,000 Ωm along line Ly6, and from 1000 to 10,000 Ωm along line Ly5 extending from the surface (0.0 m) to depths between 10 m and 20 m and to a profound depth of approximately 40 m. These high resistivity anomalies are characteristic of hydrocarbon contamination since hydrocarbons have a higher electrical resistivity compared to water. This coincides with the depth of the aquifer that serves as the major origin of edible water exploited by the local population and shows that the aquifer system below the study area, usually exploited for groundwater, has been invaded by hydrocarbon contamination plumes. The groundwater specimens from five boreholes were established to have a common total petroleum hydrocarbon (TPH) amount of 739.51 μg/L, above the DPR target and intervention thresholds of 50 and 600 μg/L, respectively. Groundwater specimens with summed polycyclic aromatic hydrocarbons (ΣPAHs) consist of amounts ranging from 0.36 to 1.89 μg/L in BH-1 to 5, that outweigh the DPR target threshold of 0.15 μg/L. Additionally, BTEX concentration was observed in greater levels in the water specimens above the DPR allowance. These findings explain that the area’s groundwater is heavily contaminated by dissolved-phase contaminants due to hydrocarbon pollution. The groundwater migration flow route at the spill site shows that the dominant flow direction is towards BH4, located northwest (N-W) of the spill site. A broad characterization of the subsurface as obtained from 2D ERI and geochemical results calls for effective remediation planning at the spill site aided by information about the very possible receptor locations at high possibility of contamination, which was defined in the groundwater flow pattern at the spill site.

Sediment deposition poses significant challenges to marine transport, aquatic ecosystems, andhydrogeological exploration. This study investigates the integration of Acoustic Doppler Current Profiler(ADCP) data with grain size analysis to estimate sediment deposition velocities in a lagoonal environment.Data from ten ADCP measurements revealed varying velocities, with the highest at 7.70 ft/s and the lowest at0.99 ft/s. Analysis of ADCP data indicated high velocity zones at depths of 21 to 27 ft and 12 to 19 ft, while lowvelocities were observed at shallow depths (up to 18 ft) and near the bottom at specific locations. Concurrentgrain size analysis identified a predominance of coarse-grained sand, with varying degrees of sorting frommoderately well to poorly sorted sediments. The results demonstrated that areas of high sediment velocityare associated with larger grain sizes, whereas low velocity zones correspond to finer grains. This studysuggests optimal navigation routes for vessels around the lagoon’s middle and recommends dredging edgesto mitigate sediment accumulation. These insights provide valuable guidance for sediment management,coastal engineering, and marine transportation safety.

This research presents an analysis of the estimated solar radiation using maximum and minimum daily temperatures (Tdmax and Tdmin) by applying three models, with calibration using the recently developed CSR model and extensive digital datasets from satellite observations compiled in the Atlas of Solar Radiation for Saudi Arabia, edited by KACST in collaboration with the Center for Renewable Energy Resources of Colorado; the model’s performance was analyzed using four statistical metrics (RMSE, ME, R², MAE), aiming to assess variability and identify the best model for estimating daily solar radiation based on temperature data from 1985 to 2018, relying on a daily dataset of extreme temperatures collected over 34 years (1985–2018) from meteorological stations in Abha (41112), Makkah (41030), Tabouk (40375), Yanbu (40439), Qaysumah (40373), Dammam (40417), Al Jouf (40361), Qasim (40405), and Najran (41118), all supervised by the National Center of Meteorology (NCM); the methodology involves analyzing the statistical distribution of the selected dataset, including maximum daily temperature (Tx), minimum daily temperature (Tm), and daily average temperature (T’), over the period 1985–2018 using the Kolmogorov-Smirnov test, while the statistical significance of temperature trend variations was examined using the semi-averages method and the T-student test, with results visually represented on thematic graphs, revealing spatial variations in daily temperatures and their trends across the selected meteorological stations, showing notable differences in the spatial distribution of daily temperatures, and in the context of trend analysis, the T-student test indicated clear differences between the semi-averages for the two periods 1985–2001 (X’1) and 2002–2018 (X’2), where the temperature differences (X’2–X’1) for minimum and maximum values were generally smaller than (2 SE) across different months in the selected stations, with the mean daily temperature exhibiting an increasing but not statistically significant trend in the studied stations; this study effectively represents the spatial distribution of daily temperature variations using statistical tests to determine the significance of trends from 1985 to 2018, demonstrating that the integrated application of these methods provides more accurate results in identifying climate change indicators across regions of Saudi Arabia.