Fjords occur in different parts of the world suggesting a common origin. Although being the subject of debate for more than a century, a common origin has not yet been disclosed; the relative importance of glaciation is still controversial. Here I propose that the primary origin of fjords, like submarine canyons, occur as a consequence of decompression-driven Earth surface curvature changes, and suggest that glaciation, rather than being the primary agent of fjord formation, as widely assumed, instead is the principal agent of fjord preservation.
An integrated 3D sesmic data and a suit of well logs of Fareed six wells located at the Fareed field Niger Delta Nigeria were analysed with Petro Tech Software for reservoir characterization and volumetric analysis. Average reservoir parameters such as porosity (0.30), hydrocarbon saturation (0.25), gross thickness (27 m), and net thickness (0.7) were derived from petrophysical analysis. Sesmic section analysis showed fault assisted anticlinal structures which served as structural traps. The volume of hydrocarbon originally in place was estimated to be 325,000 million barrels of oil within Fareed field.
The Mediterranean Sea receives domestic, agricultural and industrial untreated wastewaters from many cities and surrounding villages between Damietta and Port Said. The present study was to obtain a preliminary assessment about the level and distribution of some heavy metals (Fe, Mn, Cu, Pb and Zn) in its surface sediment collected from 14 stations. The metal concentrations (in µg/g) ranged: Fe, 947-1483; Mn, 47.58-257.1; Cu, 1.629-14.69; Pb, 1.16-19.07; and Zn, 7.996-400.3. Spatial variation in concentrations was observed for all metals. Pollution status was evaluated using five indices: The enrichment factor, geo-accumulation index, contamination factor, degree of contamination and pollution load index. Based on enrichment factors, geoaccumulation index and contamination factor, it was noticed that Zn was the major pollutant in the present study. The high values for Zn and Pb were given an indication that its sources had the highest anthropogenic inputs. This study revealed a severe enrichment for Zn and Pb, while Cu and Mn indicated minor values. DC values of sediments samples were ranged from 0.35 to 5.27. The degree of contamination in the study area was related to low degree and moderate degree of contamination. PLI values of sediments in the different sites of sediment samples ranged from 0.040 to 0.395 with average of 0.221. The decrease in PLI values indicating dilution and dispersion of metal content with increasing distance from source areas.
This study was designed to proposed a multivariate model of monthly mean daily Photo synthetically active radiation (PAR) from the constant ratio of the global solar radiation for six selected tropical ecological zones between 4.40°N and 13.03°N of Nigeria (Port Harcourt, Enugu, Abeokuta, Ilorin, Bauchi and Sokoto). The measured global solar radiation data was obtained from the Archives of the Nigerian Meteorological Agency, Oshodi, Lagos, over a period of thirteen years (2000-2012). The estimation was based on a correlation between clearance index, PAR and extraterrestrial computed using generalized 45% and 40% of monthly mean daily data set of global solar radiation and extraterrestrial solar radiation respectively on horizontal surfaces. The performance of the models developed were tested for validation using mean bias error (MBE), root mean square error (RMSE), mean percentage error (MPE), Nash-Sutcliff equation (NSE), chi squares (χ2) and index of agreement (d). The polynomial regression model developed to estimate PAR judging from the model performance and validation test indicates that the proposed model could be used to estimate PAR in six tropical ecological zones in Nigeria and other stations with similar climatological conditions across the globe. The paper also revealed that there is an apparent increase in the magnitude of PAR and clearness index along tropical belts as a result of the movement of the Hadley cell circulatory system along the equatorial line from the Sahel Savannah to the Mangrove Swamp belt.
This article deals with speleology applied to the exploration of a siphon named “Combe du Creux”. It is located in France, in the department of the Doubs. We present surveys and the specific forms that are encountered in this flooded cave; eventually we propose a possible evolution of this sump.
Cave diving, regarded as cave science, closely associated to underwater photography, is a good mean to investigate such a cave.
We have been diving in this sump since 2003 and we present the results of 13 years of explorations, up to July 2016.
After having explored this cave up to the farthest known point, we made a survey (elevation and plane view). Further dives, using a rebreather when necessary, enabled a work of observation and underwater photography.
We observed concretions – limestone as well as clay – and potholes below the current water level. We also observed ribs and scallops. The underground development of the cave seems well correlated with geologic elements that can be observed outside.
The set of all the observations leads to the conclusion that, at long time scale, the water level has fluctuated. It has been, at least once, 46 m (151 ft) below its current position. In one place inside the cave, it has been observed interactions between flutes and scallops: this new information should be taken in account in any new theoretical or computational modeling of scallops.
The aim of this study was to identify the problems of domestic water supply in Dutsen Kura Gwari Area of Chanchaga Local Government Area, Niger State, Nigeria and to determine the major source of domestic water supply in the area, while finding out the extent and challenges encountered in the process of sorting out drinking water and examining the health effect of water problems on the residents. This was carried out by getting first hand information from the residents, water board officials and health workers in order to get more reliable conclusion and provide strategies in which the adverse effect of this problem can be curtailed. Field investigations and statistical analysis revealed that tap water supply in the area is not sufficient and most of the wells dry up in the dry season. However, 33.3% of the total sampled population have tap water supply in their homes and feel little or no impact of water problems while 67% are without tap water supply. This has compelled most of the residents of the area to resort to other alternatives which are privately owned commercial boreholes, water vendors and hand dug wells. Observation and findings showed that most parts of the area was very dirty with feces and domestic wastes dumped; and the most common water borne diseases experienced in the area in the order as reported by health officials are as follows; typhoid (40%) cholera (34%), dysentery (20.8%) and guinea worm (4.1%). Investigation revealed that water problems have brought up a lot of hardships to the residents irrespective of their age, sex, occupation. So in view of these, it was concluded that water supply is a serious problem in the study area and it was recommended that the inhabitants of this area who are in better position should do their best in trying to reduce these prevailing problems. Communal efforts were also encouraged and the government was also advised to play its own role.