Malaysian Journal of Geosciences (MJG)

The Makran Subduction Zone, straddling the nothern Arabian Sea along the borders of Pakistan and Iran, represents one of the most seismically complex regions on Earth, where the Arabian, Eurasian, and Indian plates converge. This study delves into the seismic intricacies of Eastern Makran, an area delineated by a labyrinth of tectonic demarcations including the Zendan, Jiroft, and Ornach-Nal faults, to uncover the underpinnings of its seismicity through an analysis of focal mechanism solutions (FMS) for earthquakes occurring between 1990 and 2019. Utilizing the Kikuchi and Kanamori method for modeling teleseismic P-waves and their surface reflections, this research filters through the data, discarding those compromised by noise, to present a clear picture of seismic activity ranging in magnitude from 4.0 to 7.8 Mw. Contrary to the expected prevalence of major earthquakes, findings reveal a rarity of such events in Eastern Makran, suggesting a nuanced interaction between the Indian and Eurasian plates marked by anticlockwise rotation. This rotation potentially fosters the isolation of microplates, hinting at a dynamic interplay of tectonic forces. Our comprehensive 30-year perspective provides new insights into the focal depths and fault plane solutions, contributing to a better understanding of the seismic behavior and tectonic mechanisms governing the Eastern Makran Subduction Zone.

Siltation, the accumulation of sediment particles in aquatic environments, poses significant challenges to water resource management, ecological health, and infrastructure maintenance. To effectively monitor and manage siltation, accurate data acquisition methods are crucial. Bathymetric data offer high-resolution spatial data, allowing for precise identification of sediment accumulation zones and the tracking of sediment transport pathways. This study focuses on siltation monitoring within an inland water channel: Abuloma River, using the bathymetric surveying data, which involves measuring the depth and morphology of water bodies. The bathymetric data was acquired using MK III single beam dual frequency echo sounders, processed and analyzed using Qinsy software. ArcGIS software was used to quantify sediment deposition rates, distribution, and changes in underwater topography. The result of the study shows a siltation rate of 762.249m3/year. This study underscores the importance of bathymetric surveying as a powerful tool in siltation monitoring efforts. It emphasizes the need for interdisciplinary collaboration between hydrologists, engineers, ecologists, and GIS specialists to effectively analyze and interpret the collected data. Ultimately, siltation monitoring using bathymetric surveying data contributes to a holistic approach in managing sediment-related challenges and promoting sustainable water resource management practices.

One of the most used geophysical tools for characterization of the near surface is electrical resistivity tomography (ERT). The 2D resistivity survey was conducted along ten (10) buildings in Federal University Lokoja (Fulokoja), Adonkolo Campus. Dipole-dipole electrode configuration was conducted for data collection. Enhancing of measured field and calculated apparent resistivity details/data and interpretation of Electrical Resistivity Tomography (ERT) were generated using RES2DINV software which reveal a change in soil resistivity and type. From the result it is observed that the soil is made up of weathered migmatite rock which exist in layers of low resistivity, intermediate resistivity and high resistivity zone. The low resistivity zone is the uncompacted soil which provide an unstable foundation for the building while intermediate and high resistivity zone representing the fairly compacted to compacted soil which provide stable foundations for the buildings. The presence of clayey materials and oversaturated soil around the central part of the campus is the cause of the uneven ground settlement underneath these buildings causing the apparent cracks on some superstructures. The foundation of structures and buildings should be strengthened by mixing of the soil with gravels to enhance stability. Proper electrical resistivity survey and soil penetration test on the soil should be carried out prior to construction of buildings in the campus.

Lying somewhere between Production Geology, Operations, Seismology, Reservoir Engineering and Production Technology, petrophysics plays a key role in ensuring the successful development of a well, and the characterization of a reservoir. The exploration of hydrocarbon exploration in Niger Delta spans over
several decades althogh the exploration exercise is gradually shifting to the deep offshore, the channel sand deposits is targeted as the main exploration point for both the onshore and offshore exercise. This research paper reiterates the relevance of petrophysical analysis of well log data in establishing the hydrocarbon potential of sandstone reservoirs of Niger Delta Basin. The well logs data was obtained in electronic version (LAS file), the quality checks, accuracy, content policy and confidentiality remained the right of Department of Petroleum Resources (D.P.R.) Nigeria. The wireline data comprises of gamma ray, resisitiviy (deep), sonic, and neutron logs, intergrated with the calculated field curves which include archies water saturation (SW), total porosity (PHiT), bulk-volume water (BVW) and shale volume (VSH), from two exploratory wells namely EMI-04 and EMI-05. The interpretation for the petrophyiscal analysis was conducted using Schlumberger’s PETREL E&P software 2013, while the field recorded logs and the calculated curves were all presented in different tracks Several hydrocarbon bearing intervals were delineated from the interpretation of these suites of wireline data. The hydrocarbon bearing intervals across the two wells were categorized into three distinctive reservoirs, Reservoir A, encountered between intervals 2610ft and 3068ft, has an average pay thickness of 40.4ft, Reservoir B encountered along interval 4011ft to 4690ft has an average pay thickness of 16ft, reservoir C encountered between interval 5305ft and 6930ft with an average pay thickness of 61ft. The average hydrocarbon saturation, effective porosity and bulk-volume water for reservoir A, B and C, are 52%, 32% and 0.0580; 35 %, 28% and 0.2096; and 42%, 22% and 0.1572 respectively. The values of effective porosity and hydrocarbon saturation calculated for the hydrocarbon bearing zones are good enough for commercial accumulation and production of hydrocarbon. The petrophysical analysis of these reservoirs indicated that, the reservoirs could be highly productive. Due to the limited availability of logs, two types of fluids; water and hydrocarbon could be delineated.

Earthquake early warning systems have become vital for minimizing damage from seismic events. However, their automated detection capabilities need strengthening to provide real-time alerts. Current algorithms have limitations in identification of P-waves and magnitude estimation, impacting warning lead times. Additionally, existing single-algorithm dependent systems are prone to errors. There is a need for standardized practices to optimally select and combine algorithms. Machine learning and artificial intelligence show promise to make detection more robust. Models trained on diverse seismological data can learn complex patterns to detect emergent P-waves earlier and refine magnitude assessment. However, research exploring such data driven approaches within early warning systems is limited. This aims to address this research gap and strengthen automated detection capabilities. It proposes a machine learning model integrating multiple existing algorithms using a novel prioritization framework. Performance is evaluated on real earthquake datasets through simulations vis-à-vis single algorithms. By developing an optimized multi-algorithm framework, hence it seeks to improve warning lead times and reliability. The model is designed considering operational requirements of early warning systems. Comparison of results with past methods helps evaluate contributions to the field. Overall, the research strives to enhance seismic hazard mitigation through more efficient automated detection in early warning networks.

The study on petrophysical properties have been conducted. The wells (X1, X2 and X3) in the Zeta Field may be developed if the result of investigation is appreciable as it is necessary for well development, well bore stability and could be used to characterize oil reservoirs. Microsoft excel was adequate for the data processing and analysis. The petrophysical properties results for well X1 include average values of water saturation, porosity and permeability as 0.30 (30%), 19% and 10.36 millidarcy. This means that about 70% hydrocarbon saturation could be available with adequate connectivity of pores for accumulation and migration of reservoir fluids. For well X2, the average is 0.16 (which is 16%), 30%, and 21.54 millidarcy respectively. Therefore, the hydrocarbon saturation is about 84% with a very good class of porous formation and therefore can store and transmit fluid. The average noted from well X3 for water saturation, porosity and permeability correspond to 0.27 (27%), 24% and 13.42 millidarcy. The average results of the other properties studied include Shear Modulus, Lame`s Constant, and Young`s Modulus as 9.20 x 109 N/m2, 5.0 x 1013 N/m2 and 2.12 x 1010 N/m2 ,respectively from well X1. Also, the average obtained from well X2 are 3.94 x 109 N/m2 for Lame`s Constant, 5.82 x 109 N/m2 for Shear Modulus and 1.34 x 1010 N/m2 for young`s modulus. Well X3 findings have the average results as Shear Modulus = 7.64 x 109 N/m2, Lame`s Constant = 5.18 x 109 N/m2 and young`s modulus = 1.77 x 1010 N/m2. These results indicate that the studied reservoir formation is brittle and wells could stand a test of time. This information implies that the hydrocarbon saturation is about 73%, highly porous and has the ability to accumulate and migrate fluids. The results of their dependent parameters are presented in section 4. Properties like acoustic impedance and shear impedance have an average of 7.5 x 106 and 4.6 x 106 for well X1, 5.7 x 106 ,and 3.5 x 106 for Well X2; 6.7 x 106 and 4.1 x 106 ,for Well X3 respectively.

Permeability information is a necessary requirement to assess the migration and accumulation of fluids in the reservoir. Three well data (A, B, C) were available for this investigation. Microsoft Excel was used for the analysis and computation of results. Spurious values were noted and removed. Porosity was first determined and their average results for Wells A, B and C are 17.26604%, 22.83019% and 13.35095% respectively. These values of porosity indicate the reservoir classes of Wells A, B and C as good, good and fair correspondingly. This information enables the determination of average permeability of wells A, B and C corresponding to 80975.24 Darcy, 105407.1 Darcy and 65580.38 Darcy. Therefore, the reservoir of wells A and B are highly porous and permeable for the storage and migration of fluids. They should be developed for hydrocarbon exploration. This is because the porosity and permeability values of these wells are reasonable as they have met the standard. However, well C is permeable but not reasonably porous as it belongs to a fair class. The velocity information would give account of the rock elastic properties in terms of strength.

This research investigates and report zircon U-pb age of a migmatite-gneiss in Idanre, southwestern Nigeria and the petrological implications of this U-Pb age. Field geology reveals Idanre migmatite isa diatexite withnebulitic structures and the gneiss,a metatexite with perverse deformation. The migmatite-gneiss which forms the country rockis a low-lying geomorphologic unitintruded by granite plutons and batholiths. Zircon grains recovered from the migmatite-gneiss have variable sizes and morphology. Geochemicalinvestigation of the zircon revealed Uranium contents range between 80.838 to 116.736 ppm, Th contents between 25.647 ppm and 38.227 ppm while Th/U ratio falls between 0.299 and 0.365. 206Pb/207Pb age of the migmatite-gneiss ranges from 1051 to 1082 Ma with weighted average 1065.1 ± 7.1 Ma (MSWD = 0.28).The age of migmatite-gneiss fallsoutside the Archean-Early Proterozoic (3200-1600 Ma) age bracket reported for migmatite-gneissin other parts of Nigeria.Even though, the 1.065 Ga age of the migmatite-gneissis comparableto granite-gneiss from central Zambezi which crystallized around 1005–1018 million years ago and Phyllite from the Maru schist belt of north central Nigeria which yielded 1110 Ma.However,the migmatite-gneiss age is uncommonin neighbouring Pan-African belt, it is older than the Bayudian event (~0.92 Ga) of the Bayuda Desert of Sudan. This suggests the Idanre migmatite-gneiss probably represents anatectic product of yet another ancient Archean protolith.

Bathymetric information is vital for navigational safety and is utilized for many more activities. Remote sensing data and satellite images are widely used these days to determine shallow coastal areas’ bathymetry at a low cost. This study reviewed different methods for satellite-derived bathymetry and selected the ratio transform method to apply to Landsat 8 imagery. Two images covered the northern coastal region of the Bay of Bengal. They were processed using a ratio-based algorithm calibrated with reference data. A hydrographic chart from the Bangladesh Navy depicted a general overview of the study area. Another chart from the BIWTA, along with GEBCO gridded bathymetry data, was used as reference data for the study. The ArcGIS and ENVI image processing software was used to process and analyze satellite imagery. The correlation between the satellite-derived bathymetry and reference data was also studied at the end of the study. The mean absolute deviation, mean squared error, and root mean square error were also evaluated. Both algorithms were able to extract bathymetry up to a depth of 12 meters with minimal errors. Satellite Derived Bathymetry (SDB) from the Central Coast resulted in an R-squared value of 0.82 with a Mean Absolute Deviation (MAD) of 0.89. SDB from the Western Coast had R2 of 0.81 and MAD of 1.16. After interpolating the algorithm results, contour lines were also generated to visualize the bathymetry. The deviations and irregularities in the contours resulted due to the high turbidity of the coastal waters of the Bay of Bengal.

The utilization of recycled waste materials in geotechnical and civil engineering presents an eco-friendly approach to waste management, with the potential to enhance soil properties. Scrap tyres, in particular, possess valuable characteristics that can be effectively harnessed for various engineering applications. This study conducted in sector H-12, Islamabad, Pakistan,examines the impact of incorporating crumb rubber, obtained from scrap tyres, as an additive in clayey soil. Soil specimens were statically compacted at optimum moisture content and maximum dry density, incorporating 3%, 5%, 7%, 10%, and 15% by weight of crumb rubber into the base soil. The experimental results indicate a reduction in optimum moisture content and maximum dry density. The California Bearing Ratio (CBR) strength demonstrated an initial increase with up to 7% rubber incorporation, followed by a subsequent decline. These findings suggest that waste crumb rubber can be effectively employed in various geotechnical applications up to a certain proportion, offering a sustainable solution for waste management and soil enhancement.