In the physical sciences, attempts to describe processes, events, and phenomena upon the basis of problematic paradigms can be wholly incorrect and lead to physically impossible consequences, e.g., the ultraviolet catastrophe of radiation physics, and/or can necessitate ad hoc assumptions and can be unreasonably complex, e.g., the epicycles of planetary physics. Like epicycles, I suggest that supercontinent cycles, sometimes referred to as Wilson cycles, are artificial constructs, attempts to describe geological observations upon the basis of problematic paradigms. Here I describe the foundation for that assertion and offer insight into a fundamentally different geoscience paradigm, Whole-Earth Decompression Dynamics, which obviates the need to assume supercontinent cycles.
This question appears to be anachronistic in the sense that, as at today, Geography – both physical and human - has fully embraced and adopted Positivism as a philosophy and methodology of acquiring valid knowledge. Therefore, it is no longer a question of inevitability but rather its suitability and sustainability. Nevertheless, this paper attempts to describe Positivism as a philosophical and methodological approach, traces the history of its introduction into geographic inquiry, evaluates its contributions and criticisms, and finally examines what it portends for the future.
Total anthropogenic greenhouse gases have continued to increase with municipal solid waste dumpsites contributing immensely to the high concentrations of greenhouse gases with high warming potentials. This study is aimed at determining the global warming potentials of municipal solid waste dumpsite in Calabar metropolis. Soil, leachate and solid wastes samples were collected from the dumpsite and subjected to standard microbiological analysis. The samples were examined for temperature, pH, mean heterotrophic bacterial/ fungal counts and greenhouse gases emissions from the dumpsite using Combustible Gas Leak Detector. The mean temperature values for both soil and leachate samples ranged from 82°F-83°F while the mean pH values ranged from 6.57-7.0. The proportion of Carbondioxide, Methane and Nitrous oxide in the studied dumpsite has significantly increased to 39%, 161% and 19% respectively. The mean total viable aerobic heterotrophic bacterial count in both leachate and soil samples ranged from 1.7 x 103 - 8.0 x 103 cfu/ml and 1.2 x 104 - 8.0 x 104 cfu/g, while the mean total viable fungal counts for both leachate and soil samples ranged from 1.0 x 105 – 5.0 x 105 cfu/ml and 2.1 x 103 – 6.0 x 103 cfu/g. The prevalent bacteria isolate from the dumpsite soil, leachate and decomposing solid waste include: Escherichia coli, Bacillus sp, Pseudomonas aeruginosa, Enterobacter sp, Klebsiella sp, Proteus sp, Salmonella sp, Staphylococcus aureus, Micrococcus luteus, and Methanococcus sp. The fungi isolated include: Candida tropicalis, Aspergillus sp, Penicillium sp, Candida parapsilosis, Candida albicans, and Saccharomyces sp. Statistical analysis of the bacterial and fungal counts showed significant difference (p<0.05) between the various sampling points. This study reveals the health, environmental, and climate hazard that could result from indiscriminate dumping of untreated wastes.
120 sediment samples collected along a 47 km transect from Ikot Abasi to Eket, Akwa Ibom State were subjected to granulometric analysis to determine their textural characteristics and depositional processes. Standard sedimentological methods involving sieve analysis were utilized to determine the various size distributions for each sample. This was further subjected to statistical treatment (mean size, sorting, kurtosis, skewness, bivariate and multivariate analyses). Results show that the samples were very fine to pebbly (3.23 to -1.53) Ø diameter in size and varies from very poorly sorted to very well sorted (2.069 to 0.294) Ø with about 86% of the samples being poorly sorted. The sediments are predominantly leptokurtic (91%), with only few (9 samples) being platykurtic (range 8.148 to -1.082) Ø and are coarse to very fine skewed in nature. The dominant modes of transportation reflected by these sediments are saltation and surface creep attributed mostly to current and channel action. Bivariate analysis revealed that most of the sediments are associated with fluvial processes of deposition with beach processes being subordinate. Multivariate analysis showed that shallow marine agitated environment mostly characterized the sediments of this study area. CM pattern for the sediments reveal deposition was mainly by graded suspension to bottom suspension and rolling. These features characterize sediments deposited by fluvial processes dominated by tractive current patterns in a shallow marine depositional environment.
Nowadays, the dynamics of the Senegal river delta ecosystem has attracted the attention of the authorities because of the profound changes which it is subject. This study aims to analyze the relationship between the dynamics of land use units and natural and anthropogenic factors. It is performed by means of remote sensing and GIS data. Landsat images, acquired in 1977, 1988, 1999, 2006 and 2014 are chosen for this purpose. Supervised classification by maximum likelihood on neo-channel (ACP and NDVI), has allowed making the evolution of landscape units cards. These results are coupled with field data and statistics obtained in the state structures. The analysis showed that the natural and human factors are causing mutations noted in the Senegal delta ecosystems. Supervised classification has to show an expansion rate of vegetation cover (64%) crop areas (6.77%), surface water (4%) and regression of salted areas (74.69%) and dune (15.62%) between 1977 and 2014. The significant increases are due mainly to irrigation schemes, population growth and protection policies and conservation of natural resources while regressions observed, are related to the development of the agricultural sector in recent years and the importance of rainfall limiting biophysical processes. The results of this study can serve as capacity strengthening tools for actors in the field, to the understanding of the mechanisms and processes of degradation of delta ecosystems to consider adaptation measures on the rational management of space natural.