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21.
In this study, a total of 100 samples from 25 brands of carbonated natural mineral waters (CNMWs) produced in Turkey were analyzed for a total of 36 water quality constituents to determine their suitability for human consumption. Parameters examined include pH, electrical conductivity, ammonia, nitrate, nitrite, sulfate, sulfite, orthophosphate, chloride, fluoride, bicarbonate, and 25 major/trace elements analyzed by inductively coupled plasma‐mass spectrometry (ICP‐MS). The presence of these constituents in this type of water was investigated considering recent concerns about their quality and the lack of trace element information on the manufacturer labels. The analytical results obtained in this study were compared to the European Union (EU) norms, labeled values on bottles, as well as values from the literature. Results of this study have shown that Turkish CNMWs may contain high concentrations of sulfite, which is a known allergen, especially for chronic asthmatic population. CNMWs surveyed in this study have also appreciable amounts of fluoride (>1.5 mg L?1) that may have detrimental effects on health of children. The EU standards for As, Ba, Mn, and Ni were exceeded in seven CNMWs classified as “high mineral”. Compared to similar type of bottled waters from Europe and North America, CNMWs from Turkey generally contained higher elemental concentrations. 相似文献
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Aeromagnetic data were analyzed to determine the Curie point depth (CPD) by power density spectral and three-dimensional inversion methods within and surrounding Death Valley in southern California. We calculated the CPD for 0.5° regions using 2D power density spectral methods and found that the CPDs varied between 8 and 17 km. However, the 0.5° region may average areas that include shallow and deep CPDs, and because of this limitation, we used the 3D inversion method to determine if this method may provide better resolution of the CPDs. The final 3D model indicates that the depth to the bottom of the magnetic susceptible bodies varies between 5 and 23 km. Even though both methods produced roughly similar results, the 3D inversion method produced a higher lateral resolution of the CPDs. The shallowest CPDs occur within the central and southern Death Valley, Panamint Valley, Coso geothermal field and the Tecopa hot springs region. Deeper (>15 km) CPDs occur over outcropping granitic and Precambrian lithologies in the Panamint Range, Grapevine Mountains, Black Mountains and the Argus Range. The shallowest CPD occurs within the central Death Valley over a possible seismically imaged magma body and slightly deeper values occur within the Panamint Valley, southern Death Valley and Tecopa Hot Springs. The shallow CPD values suggest that partially molten material may also be found in these latter regions. The CPD computed heat flow values for the region suggest that the entire area has high heat flow values (>100 mW m?2), on the other hand, locally extremely high values (>200 mW m?2) occur within the Panamint Valley, the southern and central Death Valley and Tecopa Hot Springs region. These locally high heat flow values may be related to midcrustal magma bodies; but additional geophysical experiments are needed to determine if the magma bodies exist. 相似文献
23.
Focal depth,magnitude, and frequency distribution of earthquakes along oceanic trenches 总被引：1，自引：0，他引：1
O. S. Hammed O. I. Popoola A. A. Adetoyinbo M. O. Awoyemi G. O. Badmus O. B. Ohwo 《地震科学（英文版）》2013,26(2):75-82
The occurrence of earthquakes in oceanic trenches can pose a tsunami threat to lives and properties in active seismic zones. Therefore, the knowledge of focal depth, magnitude, and time distribution of earthquakes along the trenches is needed to investigate the future occurrence of earthquakes in the zones. The oceanic trenches studied, were located from the seismicity map on: latitude +51° to +53°and longitude-160° to 176°(Aleutian Trench), latitude+40° to +53° and longitude +148° to +165°(Japan Trench), and latitude-75° to-64° and longitude –15° to+30°(Peru–Chile Trench). The following features of seismic events were considered: magnitude distribution, focal depth distribution, and time distribution of earthquake. The results obtained in each trench revealed that the earthquakes increased with time in all the regions. This implies that the lithospheric layer is becoming more unstable. Thus, tectonic stress accumulation is increasing with time. The rate of increase in earthquakes at the Peru–Chile Trench is higher than that of the Japan Trench and the Aleutian Trench. This implies that the convergence of lithospheric plates is higher in the Peru–Chile Trench. Deep earthquakes were observed across all the trenches. The shallow earthquakes were more prominent than intermediate and deep earthquakes in all thetrenches. The seismic events in the trenches are mostly of magnitude range 3.0–4.9. This magnitude range may indicate the genesis of mild to moderate tsunamis in the trench zone in near future once sufficient slip would occur with displacement of water column. 相似文献
24.
The assessment of water resources in the Rift Valley environment is important for population, agriculture and energy-related issues and depends on a good understanding of the relationship between freshwater lakes and regional groundwater. This can be hampered by the amount of fluid-rock interaction which occurs throughout the rift, obscuring original hydrochemical signatures. However, O and H stable isotope ratios can be used as tracers of infiltration over sometimes considerable distances, while showing that the volcanic edifices of the rift floor have varying effects on groundwater flow patterns. Specific cases from Kenya and Ethiopia are considered, including Lakes Naivasha, Baringo, Awasa and Zwai.In addition to their physical tracing role, stable isotopes can reveal information about processes of fluid-rock interaction. The general lack of O isotope shifting in rift hydrothermal systems suggests a high water:rock ratio, with the implication that these systems are mature. Carbon isotope studies on the predominantly bicarbonate waters of the rift show how they evolve from dilute meteoric recharge to highly alkaline waters, via the widespread silicate hydrolysis promoted by the flux of mantle carbon dioxide which occurs in most parts of the rift. There appears to be only minor differences in the C cycle between Kenya and Ethiopia. 相似文献
25.
Musa Güner 《International Journal of Earth Sciences》1983,72(1):239-252
The basaltoids of the Küre area, Pontides of northern Turkey, associate with eugeosynclinal greywackes and black shales. They comprise massive flows, pillow lavas, and cutting diabase dikes. In the submarine environment and still more during the formation of the Küre copper ores, the basaltoids were severely altered, which affected particularly their alkali contents. In spite of variable proportions of main components, the study of stable trace elements permits a confident identification of the rocks as tholeiites of ocean floor affinity. The Küre basaltoids are considered to have been generated during the expansion of the marginal basin of the Anatolian troughs. 相似文献
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A.A. Adepelumi B.D. Ako T.R. Ajayi A.O. Olorunfemi M.O. Awoyemi D.E. Falebita 《Journal of African Earth Sciences》2008,52(4-5):161-166
Integrated geophysical methods involving magnetic and dipole–dipole resistivity (DDR) were conducted across a prominent zone of weakness clearly observable in Landsat MSS and SLAR images in the Precambrian basement complex of southwestern Nigeria. Up till now, the location and existence of this megascopic structure have not been confirmed using geophysical methods. With the objective of delineating this weak zone and its structural attributes, three traverses were established at 500 m intervals across it, and geophysical measurements were made at 10 m intervals along these traverses. Qualitative interpretation of the magnetic data obtained shows a diagnostic signature of a near-vertical fault, trending along a NNE–SSW direction. Also, the quantitative interpretation of the data using the non-linear least-squares regression technique indicates that the width of the magnetic anomaly ranges from 90 to 150 m, its dip angle varies between 75° and 85°; the anomaly is concealed by a regolith of approximately 15 m thickness. Furthermore, a 2D resistivity inversion of the field resistivity data reveals a three-layer model, representing thin resistive topsoil underlain by weathered bedrock, resistive bedrock with a distinct low resistivity zone located within the bedrock. The most plausible explanation for this low resistivity zone is that it was formed by shearing activities during Late Precambrian times. Conclusively, the integrated approach employed in this research confirms the existence of the supposed Ifewara shear zone (ISZ). 相似文献
28.
Musa Ataṣ Ahmet Emre Tekeli Senayi Dönmez Hesham Fouli 《Arabian Journal of Geosciences》2016,9(2):150
Basins located in Eastern Turkey are largely fed by snowmelt runoff during spring and early summer seasons. This study investigates the efficiency of artificial neural networks (ANNs) in snowmelt runoff generation. Although ANNs have been used for streamflow simulating/forecasting in the last two decades, using satellite-based snow-covered area (SCA) maps and meteorological observations as inputs to ANN provides a novel basis for estimating streamflow. The proposed methodology is implemented over Upper Euphrates River Basin in Eastern Turkey. SCA data was acquired from Interactive Multisensor Snow and Ice Mapping System (IMS) for an 8-year period from February 2004 to September 2011. Meteorological observations including daily cumulative precipitation and daily average air temperatures were obtained from Turkish State Meteorological Services. The simulation results are promising with coefficient of correlation varying from 0.67 to 0.98 among proposed models. Past days discharge was found to substantially improve the forecast accuracy. The paper presents the expected basin discharge for 2011 water year based on meteorological observations and SCA input. 相似文献
29.
Adabanija Moruffdeen Adedapo Olayinka Abel Idowu Osinowo Olawale Olakunle Junaid Abdulquadri Tayo Adebayo Isiah Olufemi 《Geotechnical and Geological Engineering》2021,39(5):3689-3727
Geotechnical and Geological Engineering - The stability of the pavement system on old Ogbomoso-Ilorin road in southwestern Nigeria basement complex was investigated. This was carried out by... 相似文献
30.
Husam Musa Baalousha 《Environmental Earth Sciences》2012,66(1):285-294
Modelling groundwater and surface water is important for integrated water resources management, especially when interaction
between the river and the aquifer is high. A transient groundwater and surface water flow model was built for Ruataniwha basin,
New Zealand. The model covers a long-time period; starting in 1990, when water resources development in the area started,
to present date. For a better resolution, the simulation period was divided into 59 stress periods, and each stress period
was divided to 10 time steps. The model uses data obtained from surface water, and groundwater collected over the last 20 years.
Rivers and streams were divided into 28 segments and flow and streambed data at the beginning and end of each segment was
used. Parameter estimation and optimisation ‘PEST’ was used for automatic calibration of hydraulic conductivity, groundwater
recharge and storativity; whereas riverbed conductance was manually calibrated. Model results show that the rivers gain from
the aquifer considerably more than the river losses. The cumulative groundwater abstraction over the last 20 years is approximately
210 million m3. This amount is very low compared to other water budget components; however, the effect of groundwater abstraction on storage
is significant. Based on the results of this study, it was found that the loss of storage over the last 20 years is more than
66 million m3. Results also reveal that the effect of groundwater abstraction on rivers and springs flow is significant. The rivers gain
from the groundwater system, and the springs flow have been decreasing. 相似文献