Earth Science Malaysia (ESMY)

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.

An overpressure zone is critical in petroleum exploration drilling, leading to potentially dangerous blowouts and other drilling-related hazards. Yet, it often contains significant hydrocarbon reserves in sedimentary basins. This research aims to determine the possible overpressure zones in the Srikail Well-1 of the Srikail Gas Field. The acoustic impedance responses of 2D seismic data for the Srikail Well-1 and its well log responses were examined to find probable overpressure zones at the Srikail Well-1. Seismic inversion is a crucial method in this study for identifying and understanding overpressure zones. Hence, the process involved extracting wavelets, conducting well correlation, determining and picking horizons, followed by model-based seismic inversion, and calibrating pressure to well logs and seismic data using Kerry 2D post-stack seismic data to derive acoustic impedance, a crucial indicator for the presence of potential overpressure. Well-log responses provided evidence for this analysis. The density and sonic log responses of the Srikail-1 well were carefully evaluated. The intervals indicating possible overpressure locations, as identified through a seismic acoustic impedance, exhibited reasonable consistency with the well-log data. The Srikail-1 well does not have enough well-log information, such as density, but it affects the changing trend of well logs. The sonic logs solely follow the rule of an overpressure zone. A cut-off frequency between 4 and 8 Hz was used to build the Srikail-01 well initial model, and the wavelet was created using well logs and seismic data. Very low acoustic impedance values are observed on the model-based inversion map of the Srikail-01 well at a depth range of approximately 3548.58m in the subsurface corresponding to the overpressure zone. Conversely, the identified overpressure zone has encountered the Bhuban formation. Bangladesh’s hydrocarbon reserves are depleting due to high consumption, but unexplored areas and overpressure zones offer untapped potential. Revisiting known structures with robust methods can help to address rising demand.

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.

An overpressure zone is critical in petroleum exploration drilling, leading to potentially dangerous blowouts and other drilling-related hazards. Yet, it often contains significant hydrocarbon reserves in sedimentary basins. This research aims to determine the possible overpressure zones in the Srikail Well-1 of the Srikail Gas Field. The acoustic impedance responses of 2D seismic data for the Srikail Well-1 and its well log responses were examined to find probable overpressure zones at the Srikail Well-1. Seismic inversion is a crucial method in this study for identifying and understanding overpressure zones. Hence, the process involved extracting wavelets, conducting well correlation, determining and picking horizons, followed by model-based seismic inversion, and calibrating pressure to well logs and seismic data using Kerry 2D post-stack seismic data to derive acoustic impedance, a crucial indicator for the presence of potential overpressure. Well-log responses provided evidence for this analysis. The density and sonic log responses of the Srikail-1 well were carefully evaluated. The intervals indicating possible overpressure locations, as identified through a seismic acoustic impedance, exhibited reasonable consistency with the well-log data. The Srikail-1 well does not have enough well-log information, such as density, but it affects the changing trend of well logs. The sonic logs solely follow the rule of an overpressure zone. A cut-off frequency between 4 and 8 Hz was used to build the Srikail-01 well initial model, and the wavelet was created using well logs and seismic data. Very low acoustic impedance values are observed on the model-based inversion map of the Srikail-01 well at a depth range of approximately 3548.58m in the subsurface corresponding to the overpressure zone. Conversely, the identified overpressure zone has encountered the Bhuban formation. Bangladesh’s hydrocarbon reserves are depleting due to high consumption, but unexplored areas and overpressure zones offer untapped potential. Revisiting known structures with robust methods can help to address rising demand.

When assessing the safety of a slope and the environmental impact resulting from open-pit and underground mining activities, it is imperative to consider the ground surface deformation induced by mining operations. Such deformations pose a significant risk to the environment, slope stability, and man-made structures within the mining activity region. Therefore, the monitoring of mining-induced ground surface deformations is crucial, and this study employs C- band Synthetic Aperture Radar (SAR) data to demonstrate the efficacy of the Persistent Scatterer Interferometric SAR (PS-InSAR) method. Specifically, the PS-InSAR method is applied to monitor ground surface deformation in the Midroc Gold Mine Company. The findings reveal that the PS-InSAR technique is capable of effectively tracking ground subsidence time-series, even in areas characterized by dense vegetation and rural landscapes. In the Midroc Lega Dembi open- pit mining region, the highest rate of ground surface deformation is observed at -90 mm per year, with cumulative subsidence values of -200 mm and -100 mm detected for ascending and descending geometries, respectively, through InSAR techniques. Additionally, ground survey data records cumulative subsidence values of -3.99866 m and -0.000122 m for ascending and descending geometries.The discrepancy between datasets is attributed to the thick vegetation cover in the study area. Integration of PS-InSAR results with ground survey data from the Midroc Lega Dembi open-pit mining zone reveals a correlation coefficient of 0.98, validating the accuracy of the PS-InSAR approach in identifying, tracking, and mapping ground surface deformation in the gold mine. This comprehensive methodology utilizes both ground survey data and C-band SAR data for a robust assessment of mining-induced ground surface deformations.