Preprints
Search for science and technology (89 results)
Mesoscale fractures control the scale dependences of seismic velocity and fluid flow in subduction zones
Published: 2024-07-27
Subjects: Geophysics and Seismology
Natural geological systems contain porosity structures of various scales that play different roles in geophysical properties, fluid flow, and geodynamics. To understand seismic activity associated with high pore-fluid pressure and fluid migration in subduction zones, it is necessary to explore the scale dependence of geophysical properties such as seismic velocity and permeability. Here, we [...]
Groundwater Exploration Methods in West Africa: A Review.
Published: 2024-07-25
Subjects: Physical Sciences and Mathematics
The focus of groundwater research has evolved, expanded, and adapted to meet the water demands of society. In recent years, discernible trends have emerged in groundwater studies, particularly in the domains of exploration and exploitation. Groundwater exploration in West Africa has predominantly been driven by demand and ease of accessing water in its hosting environment. In light of the [...]
Ongoing Research Project "THE STATUS OF NOISE POLLUTION OF SUST CAMPUS, SYLHET, BANGLADESH: A GIS-BASED NOISE MAPPING
Published: 2024-04-24
Subjects: Public Health
This study investigates the status of noise pollution at the Shahjalal University of Science and Technology (SUST) campus in Sylhet, Bangladesh, employing a GIS-based approach to map and analyze noise levels across different areas of the campus. The research was motivated by the growing concern over environmental noise as a public health issue, particularly in educational settings, where it can [...]
Moist convective scaling: Insights from an idealised model
Published: 2024-04-17
Subjects: Atmospheric Sciences
The response of clouds and moist-convective processes to heat-loss to space by long-wave radiative cooling is an important feedback in the earth's atmosphere. It is known that moist convection increases roughly in equilibrium with radiative cooling, an assumption often made in simplified models of the tropical atmosphere. In this study, we use an idealised 2D model of the atmosphere introduced by [...]
Evaluation for the Impacts of Numerical Advection Schemes and Turbulence Modeling on Gray-Zone Simulation of a Squall Line
Published: 2024-04-05
Subjects: Physical Sciences and Mathematics
With increasing computational power, atmospheric simulations have approached the gray zone resolutions where energetic turbulent eddies are partly resolved. The representation of turbulence in the gray zone is challenging and sensitive to the choices of turbulence models and numerical advection schemes. Some numerical advection schemes are designed with numerical dissipation to suppress [...]
A Review of Geological and Climatic Variables in Groundwater Availability Prediction in Africa: Machine Learning Approaches
Published: 2024-01-08
Subjects: Engineering
Groundwater is crucial for Africa's potable water supply, agriculture, and economic development. However, the continent faces challenges with groundwater scarcity due to factors like population growth, climate change, and over exploitation. Over the past ten years, machine learning has been increasingly and successfully used in groundwater level prediction across the world. This review paper [...]
Machine-Learning Approaches for Assessing Aerosol Optical Depth (AOD) in Ghana, West Africa
Published: 2024-01-08
Subjects: Education, Medicine and Health Sciences, Physical Sciences and Mathematics
In the field of environmental health, assessing air pollution exposure has historically posed challenges, primarily due to sparse ground observation networks. To overcome this limitation, satellite remote sensing of aerosols provides a valuable tool for monitoring air quality and estimating particulate matter concentration (PM) at the surface. In this study, we employ two predictive models to [...]
A Systematic Review of Machine Learning Algorithms in Groundwater Level Simulations and Forecasting
Published: 2023-12-29
Subjects: Education, Physical Sciences and Mathematics
Over two billion individuals worldwide rely on subterranean water as their primary reservoir of clean water. Ensuring the sustainable management of this heavily burdened resource necessitates a comprehensive quantitative evaluation of groundwater reserves. This becomes even more critical as water resources face escalating demands resulting from socioeconomic growth, population expansion, and the [...]
Seismic Activities in Ghana: A Systematic Review
Published: 2023-08-08
Subjects: Education, Physical Sciences and Mathematics
Seismic activities pose significant challenges to societies globally. Therefore, it is crucial to understand their occurrence, patterns, and impacts. By studying seismic activities, including earthquakes, researchers can investigate their occurrence, distribution, and characteristics which can provide effective management and risk reduction strategies. The southern part of Ghana is prone to [...]
The climate and environmental determinants of domestic water supply change at the Nasia catchment in Northern Ghana
Published: 2023-06-23
Subjects: Geography
The Nasia river serves as the primary source of domestic water supply for over 5000 households in the Nasia catchment. However, the river is currently experiencing water stress conditions, causing an imbalance between the demand for water and the available supply. In this study, we evaluated the impact of climate and environmental factors on changes in domestic water supply in the Nasia [...]
Different mechanisms of Arctic first-year sea-ice ridge consolidation observed during the MOSAiC expedition
Published: 2023-05-10
Subjects: Earth Sciences, Glaciology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Sea-ice ridges constitute a large fraction of the ice volume in the Arctic Ocean, yet we know little about the evolution of these ice masses. Here we examine the thermal and morphological evolution of an Arctic first-year sea-ice ridge, from its formation to advanced melt. Initially the mean keel depth was 5.6 m and mean sail height was 0.7 m. The initial rubble macroporosity (fraction of [...]
In-situ frictional behavior of subducting sediment in the shallow Nankai Trough
Published: 2023-04-22
Subjects: Geology, Geophysics and Seismology, Sedimentology, Tectonics and Structure
The transition from smectite to illite at around the depth with temperature of ~150 °C has long been hypothesized as one of controlling factors of the updip limit depth of the seismogenic zone of subduction zones. Although illite has a higher friction coefficient than smectite, previous friction experiments have little reported that the smectite-illite transition accompanies the transition from [...]
False positives are common in single-station template matching
Published: 2023-02-17
Subjects: Earth Sciences, Geophysics and Seismology, Planetary Geophysics and Seismology, Planetary Sciences
Template matching has become a cornerstone technique of observational seismology. By taking known events, and scanning them against a continuous record, new events smaller than the signal-to-noise ratio can be found, substantially improving the magnitude of completeness of earthquake catalogues. Template matching is normally used in an array setting, however as we move into the era of planetary [...]
Temporal evolution of under-ice meltwater layers and false bottoms and their impact on summer Arctic sea ice mass balance
Published: 2023-02-16
Subjects: Earth Sciences, Glaciology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Low-salinity meltwater from Arctic sea ice and its snow cover accumulates and creates under-ice meltwater layers below sea ice. These meltwater layers can result in the formation of new ice layers, or false bottoms, at the interface of this low-salinity meltwater and colder seawater. As part of the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC), we used a [...]
The nature of the proximal volcaniclastic materials from the 2021 eruption Fukutoku-Oka-no-Ba in the Izu-Bonin arc.
Published: 2023-01-31
Subjects: Earth Sciences, Geology, Volcanology
Fukutoku-Oka-no-Ba is a submarine volcano located at 24°17.1′N/141°28.9′E in the Izu–Bonin–Mariana arc, and is one of the most active volcanoes in Japan. This volcano produced an explosive eruption in August 2021 that generated a large amount of volcaniclastic material, some of which drifted westward to Japan and the coastal area of East Asia as a pumice raft. The pumice clasts that drifted for [...]