International Journal of Geosciences

Journal Information
ISSN / EISSN : 21568359 / 21568367
Current Publisher: Scientific Research Publishing, Inc, (10.4236)
Total articles ≅ 921
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Jingmin Guo, Wei Wang, Jie Tan, Qin Peng, Ng Zhang
International Journal of Geosciences, Volume 10, pp 405-418; doi:10.4236/ijg.2019.104023

Osazuwa Abifade Ogbahon
International Journal of Geosciences, Volume 10, pp 860-883; doi:10.4236/ijg.2019.1010049

Abstract:Palynological study of 45 ditch samples from sedimentary successions penetrated by OSE 1 well located offshore western Niger Delta Basin was undertaken to determine the age of the sediment and reconstruct the paleoclimate and depositional paleoenvironment. All the analyzed samples were composited at 30 ft from stratigraphic depth interval of 6330 to 9010 ft. The lithologic composition comprised mainly of brownish grey or light grey, fine-grained shales with a gypsiferous horizon near the bottom. Palynological slides were prepared following standard palynological preparation procedures of sample maceration with hydrochloric (HCl) and hydrofluoric (HF) acids. The samples yielded moderately well-preserved, low to high diversity palynomorph assemblages of 58 taxa comprising 29 pollen grains, 9 pteridophic spores, 17 dinoflagellates, one acritarch, one freshwater algae and a fungi spore. The stratigraphic distribution of microflora assemblages was highly variable. The assemblage abundance was dominated by pollen and spores. The retrieved pollen grains included Monoporites annulatus, Sapotaceoidaepollenites sp. Psilatricolporites crassus, Psilatricolporites sp., Zonocostites ramonae, Retitricolporites irregularis, Monocolpites marginatus, Monocolpites sp., Pachydermites diederixi, Proxapertites cursus, Verrutricolporites rotundiporus, Striatopollis catatumbus, Retistephanocolpites gracilis, Echiperiporites estalae, Echiperiporites sp. and Inaperturopollenites sp. The retrieved spores included Magnastriatites howardi, Acrostichum aureum, Laevigatosporites sp., Polypodiaceoisporites sp., Verrucatosporites sp., Crassoretitriletes vanraadshooveni and Stereisporites sp. The recorded dinoflagellates included Achomosphaera sp., Andalusiella sp., Polysphaeridium zoharyi, Selenopemphix nephroides and Spiniferites sp. Leiosphaeridia sp. was the only acritarch present in the assemblage. The freshwater algae was Botryococcus braunii. Fungi spore was present but not in significant amount. The stratigraphic interval was dated Early to Late Miocene (Burgidalian-Messinian) based on the occurrence and distribution of some stratigraphic fossil marker species including Magnatriatites howardi, Crassoretitriletes vanraadshooveni and Retistephanocolpites gracilis The abundant occurrence of pollen and spores typical of rain forest and freshwater swamp communities in the assemblage indicated tropical paleoclimatic conditions. The distribution pattern of Monoporites annulatus (Poaceae) and Zonocostites ramonae (Rhizophora) suggested seasonal fluctuations between dryer and wetter climatic conditions. The sediments were deposited in a wide range of environments including brackish lagoons, open salt water swamps, freahwater and nearshore to inner neritic settings.
Kana T. Idriss, Serge H. Pokam Kengni, Ndikum Eric Ndoh, Blaise P. Gounou Pokam, Charles T. Tabod
International Journal of Geosciences, Volume 10, pp 845-859; doi:10.4236/ijg.2019.1010048

Abstract:Geoelectric data obtained from forty (40) vertical electrical soundings collected with a Schlumberger device in the Adamawa plateau region, also known as the Cameroon water tower, have been treated by the least-squares inversion method. In order to study the nature and thickness of the aquifer and the necessary geoelectric parameters, quantitative and qualitative interpretations of the data were made. The results obtained showed that: about four to five geoelectric layers have been delimited in the study area with a dominance of the KH curve, which can be used as a reference for future studies. The first two layers constitute an association of clay and laterite with resistivity values ranging from 58 to 9122 Ω·m and whose thickness is between 0.6 and 13.4 m. The third layer is a potentially aquiferous laterite composed of clay, laterite and especially clay sand and cracked/good granite, with a dominance of sandy alteration whose resistivity values are between 81 and 960 Ω·m and its thickness between 12.2 and 26.8 m. The fourth and fifth layers are made up of cracked/good granite with a resistivity ranging from 12-10705 Ω·m with an average value of 1817 Ω·m. This study also shows that the North-East, South-West and South sectors could be the groundwater convergence zones and that the average depth of the basement aquifer roof is about 28.3 m. The geoelectric sections of certain demarcated vertical electrical sounding stations are consistent with the geologic description of the area.
Yijia Liu, Jianhua Liu, Heng Pu, Yuan Liu, Shiran Song
International Journal of Geosciences, Volume 10, pp 884-905; doi:10.4236/ijg.2019.1010050

Abstract:Aiming at the land cover (features) recognition of outdoor sports venues (football field, basketball court, tennis court and baseball field), this paper proposed a set of object recognition methods and technical flow based on Mask R-CNN. Firstly, through the preprocessing of high spatial resolution remote sensing imagery (HSRRSI) and collecting the artificial samples of outdoor sports venues, the training data set required for object recognition of land cover features was constructed. Secondly, the Mask R-CNN was used as the basic training model to be adapted to cope with outdoor sports venues. Thirdly, the recognition results were compared with the four object-oriented machine learning classification methods in eCognition®. The experiment results of effectiveness verification show that the Mask R-CNN is superior to traditional methods not only in technical procedures but also in outdoor sports venues (football field, basketball court, tennis court and baseball field) recognition results, and it achieves the precision of 0.8927, a recall of 0.9356 and an average precision of 0.9235. Finally, from the aspect of practical engineering application, using and validating the well-trained model, an empirical application experiment was performed on the HSRRSI of Xicheng and Daxing District of Beijing respectively, and the generalization ability of the trained model of Mask R-CNN was thoroughly evaluated.
Kaboré M’Bi, Zerbo Jean Louis, Zoundi Christian, Ouattara Frédéric
International Journal of Geosciences, Volume 10, pp 833-844; doi:10.4236/ijg.2019.1010047

Abstract:In this paper we report on the foF2 variabilities for two equatorial regions (Ouagadougou: Lat. 12.4°N; Long. 358.5°E, Dip. 1.43°S; and Manila: Lat. 14°36'15.12''N; Long. 120°58'55.92''E; Dip. 0.6°S) during solar cycles 20 and 21 minima and maxima phases. Many previous works have argued on the diurnal and seasonal variation of foF2 for different solar events conditions for latitudinal position. But there are few investigations for Africa equatorial region longitudinal variation. The present paper’s goal is to outline possible similarity in foF2 behavior between variations for better understanding of physical process lead to some observed phenomenon in Asia-Africa equatorial sector. The F-layer critical frequency (foF2) data observed from the two equatorial ionosonde stations have been used for the present comparative study. The results show significant similarity between the critical frequency (foF2) seasonal variations over the time intervals 1976-1996. During day-time measured data from Manila station are higher than those from Ouagadougou station. That may lie in that Manila is closer to equatorial ionization crest region. During solar minimum phase, the longitudinal variation of foF2 shows two crossing points (11:00 UT and 22:00 UT) between the foF2 profiles form the two stations for all seasons regardless of the solar cycle. However during intense solar activity condition, the number of crossing-point between measured data from Manila and Ouagadougou stations varies by seasons and solar cycle. This phenomenon may be due to the compilations of severe activities (storms, coronal mass ejection, heliosheet fluctuations) during the solar maximum phases.
Fikre Zerfu, Abdurehman Mektel, Biniyam Bogale
International Journal of Geosciences, Volume 10, pp 811-832; doi:10.4236/ijg.2019.109046

Abstract:Drastic changes have occurred in Siti zone rangeland over nearly the last three decades, due to rapid land conversion dynamics in the area. In the zone, the land-use change over time and space and temporal trends rangeland condition have never been studied. This study analyzed land use and land cover (LULC) change dynamics since the 1980s. Three dates, 1985, 2001 and 2017, Landsat images were used for classification and analysis of the various LULC. The three images were geo-referenced, re-sampled and processed for classification, using the maximum likelihood classifier algorithm. Moreover, field observations and information from local people were used for triangulation to patterns LULC dynamics. From 1985 to 2017, the general trend observed in the land use/cover change in the rangeland resources in the study districts implies a loss of grassland cover was compensated by an increase in cultivated areas, settlement and shrub/bush land cover. Moreover, the encroachments of invasive plant, Prosopis, settlement and the promotion of cultivation to pastoral way of livelihood have exacerbated the decline of rangeland cover. The study findings have shown important changes in the LULC patterns in the north-eastern Somali rangelands of eastern Ethiopia. These trends are certainly the characteristics of a pastoral way of life turn to settlement. This suggests that major changes in the socio-ecological driving forces affecting landscape dynamics have occurred in the last three decades or so.
Michael G. Noppe
International Journal of Geosciences, Volume 10, pp 785-799; doi:10.4236/ijg.2019.108044

Abstract:The article describes a project proposed to determine the epicenter of a future short-focus earthquake tens of hours before and to reduce the magnitude of an impending catastrophic earthquake. It focuses on developing a physical model to determine the conditions necessary for the start of an earthquake, for a method based on the registration of flows of mercury vapor in the gas rising from the Earth. This model gives an explanation of why an earthquake precursor appears so early (such a long period of time can range from a few to hundreds of hours). Normally, the characteristic times of an earthquake precursor for seismic methods are tens of seconds. The project is based on the physical and mathematical models of an earthquake. The derived formula for the time of the precursor of a future earthquake allows us to explain and to describe the time increase for the precursor, depending on the magnitude of the earthquake. The method of reducing the magnitude of an impending catastrophic earthquake is based on the proposed physical model of the onset of an earthquake and is implemented by the action of a vibration source in the region of the detected earthquake epicenter. The proposed system should save citizens, lives from future short-focus earthquakes.
Sanaa Al-Zyoud
International Journal of Geosciences, Volume 10, pp 906-918; doi:10.4236/ijg.2019.1010051

Abstract:Jordan is blessed with shallow geothermal resources in NE and SE deserts. Jordanian deserts compose more than 70% of the country area. Furthermore, it’s the second vital area in fauna and flora variation after Jordan valley. Geothermal gradient in this area shows high promising future potential. New renewable energy systems installation in Jordan will have a positive environmental and economic contribution to the national bill. Currently, limited geothermal utilizations were evaluated in the Jordanian deserts. Thermal waters in the deserts were used for irrigation only. Six different applications for direct and indirect geothermal applications in Jordanian deserts were suggested and evaluated. Ground source heat pumps for heating and cooling purposes and crops drying were expected to be the most appropriate applications of geothermal energy in the deserts. Geothermal utilizations were investigated regarding their probable impact on local and national economic scale. Therefore, an integrated plan for geothermal applications in Jordan is becoming very essential in the future. It has been found that geothermal energy in Jordanian deserts could be utilized for different applications. Despite of the potential political, technical and financial barriers, exploiting new geothermal utilization in the deserts will contribute to solving socio-economic and environmental problems challenging poor deserts areas.
Jiaogen Zhou, Yang Wang
International Journal of Geosciences, Volume 10, pp 919-929; doi:10.4236/ijg.2019.1010052

Nils-Axel Mörner
International Journal of Geosciences, Volume 10, pp 745-757; doi:10.4236/ijg.2019.107042