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261.
William R. Stanley Prof. Dr. 《GeoJournal》1990,22(1):67-79
Taxes and royalties from the oil industry in Nigeria have made possible massive infrastructural and social development throughout the country; this single industry continues to be the most important contributor to the national treasury. Along with oil, however, have come environmental and social problems, some severe and, in the social sector, possibly of long duration. Questionnaires were employed to solicit environmental and socioeconomic information from residents in the oil-impacted area as well as to ascertain the views of the oil companies with respect to their Nigerian operations, in particular to their socio-economic responsibilities to the local residents. Responses point to serious discontent on the part of the impacted population, especially in the most important southern (Niger Delta) oil producing region. These negative attitudes in part are based upon the impacted population’s inability to secure for itself a sufficiently large number of oil industry jobs and in part to the presence in the local community of ethnic strangers who do have such employment. There is evidence of serious environmental damage, but its biological dimension has been overshadowed by claims for monetary compensation at the local level. Data derived from these investigations might well be applicable in the wider field of trans-national mining and petroleum extraction operations in developing countries, especially to the unwritten social obligations of the expatriate firm to local residents. 相似文献
262.
Thunder-day occurrences during a 100-year period based on data from carefully screened records of 86 first-order stations distributed across the United States were assessed for temporal fluctuations and trends during 1896–1995. Short-term (<10-year) fluctuations of adjacentstations were often dissimilar reflecting localized differences in storm activity in a few years, making spatial interpretations difficult. But, temporal fluctuations based on 20-year and longer periods exhibited regional coherence reflecting the control of large, synoptic-scale weather systems on the distribution of thunderstorms over broad areas. Classification of station fluctuations based on 20-year periods revealed six types of distributions existed and they formed 12 discrete areas across the nation. One type present in the lower Midwest and the South had a peak in storm activity in 1916–1935 followed by a general decline to 1976–1995.A second type maximizing at the same time had its minimum earlier, in 1956–1975. Another distribution found at stations in the upper Midwest and Northeast had a mid-century peak (1936–1955) with a recent minimum in1976–1995. A fourth distribution also peaked in 1936–1955 but had an early minimumin 1896–1915, and it mainly occurred in the northern plains and Rocky Mountains. A fifth distribution peaked during 1956–1975 and was foundat stations in four areas including the central High Plains, Southwest, northern Great Lakes, and Southeast. The sixth temporal distribution showed a steady increase in storm activity during the 100-year period, peaking in 1976–1995, and covered a large area extending from the Pacific Northwestacross the central Rockies and into the southern High Plains. The national average distribution based on all station values peaked in mid century. The national distribution differs markedly from several regional distributions illustrating the importance of using regional analysis to assess temporal fluctuations in severe weather conditions in the nation. The 100-year linear trends of the 86 stations defined six regions across the U.S. Significant upward trends existed over most of the western two-thirds of the nation, unchanging trends existed in the northern plains and Midwest, and downward trends were found in most of the nation's east. The up trends in storm-day frequencies in the southern plains occurred where storm damage is greatest and where demographic changes have added to storm losses over time. The national patterns of trends and storm distributions were similar to those found for hail. The temporal distributions of storm activity helped explain recent increases in major storms and their losses, conditions which have increased in the west and south. 相似文献
263.
A radiocarbon-dated core, NC, taken in the alpine Blue Lake in the Snowy Mountains of southeastern Australia provides a Holocene record of sedimentation that consists mainly of organic clays. Two types of quartz grains are recovered from 81 samples from the core. One type consists of angular grains, with frequently shattered faces, which originates from granitic lithologies present within the small catchment area of the lake. The other type is characteristically rounded to subrounded, often textured with frequent silica coating and is considered to have been deposited within the lake and its catchment by aeolian processes. These aeolian grains are thought to have been transported along the main dust path that ferries aeolian dust from the Mallee region, west of the Snowy Mountains, as far as the southeastern Tasman Sea. Aeolian grains with the largest size occur over approximately the last 1.6 ka of the Holocene and this indicates an increase of climatic instability, with arid phases that commenced about 3.5 ka. At 2 ka, a wet period in southeastern Australia coincided with low aeolian input at Blue Lake. The period of consistent reduced aeolian activity spans the 7.6 to 5.5 ka interval at Blue Lake. 相似文献
264.
Stanley M. Cisowski 《Surveys in Geophysics》1990,11(1):55-131
The discovery of an excess of Ir and other noble metals in approximately chondritic proportions at numerous sites, synchronous with the Cretaceous/Tertiary (K/T) boundary, provided hard evidence for earlier suggestion that extraterrestrial envents may have coincided with many global geologic boundaries. Further support for the impact hypothesis arose from the identification of abundant microspherules and shocked quartz in K/T boundary marine and nonmarine deposits, respectively, and the discovery of an apparent periodicity in the megaextinction event record. However continuing doubts about the impact origin of the K/T spherical forms and associated geochemical anomalies, uncertainty about the range and extent of the shocked quartz distribution, and the lack of a large, suitably-aged crater, has led to an alternative hypothesis calling upon purely endogenic processes to account for the boundary layer phenomena. Advocates of this opposing theory generally call upon large scale, possibly periodic injection of mantle material directly into the lithosphere. While a number of arguments can be made from the the existing data base for and against both competing theories, other evidence suggests that additional phenomena, including sudden changes in the physical and chemical conditions of the oceans, natural combustion on a global scale, and/or widespread sediment-contaminated volcanism, may have contributed to the dramatic transition recorded in the K/T boundary rock record. 相似文献
265.
Abstract. The 1984 Ohio Supreme Court ruling on Cline v. American Aggregates changed Ohio's ground-water law from an 1861 ruling based on the English Rule of absolute ownership to a doctrine of reasonable use which recognizes that landowners have the privilege to use the water beneath their land but can be held liable to others if their use of ground water causes others unreasonable harm. The Ohio Supreme Court did not define unreasonable harm in the Cline case. As a result, unreasonable harm is being established through case law, the first such case being the relitigation of Cline v. American Aggregates.
Depositions and expert testimony presented during the Cline cases, which represent a group of 56 landowners in a single lawsuit, showed the diverse ways in which the quantity and quality of ground water used for domestic-water supplies were affected by operation of a dewatering system at an aggregate mine. The testimony highlighted the complex interaction between regional hydrodynamics, variations in local hydrogeologic settings, well-construction methods, spatial variations in infiltration and recharge, and vertical leakage with the effects of the regional decline in water levels produced by the dewatering system. 相似文献
Depositions and expert testimony presented during the Cline cases, which represent a group of 56 landowners in a single lawsuit, showed the diverse ways in which the quantity and quality of ground water used for domestic-water supplies were affected by operation of a dewatering system at an aggregate mine. The testimony highlighted the complex interaction between regional hydrodynamics, variations in local hydrogeologic settings, well-construction methods, spatial variations in infiltration and recharge, and vertical leakage with the effects of the regional decline in water levels produced by the dewatering system. 相似文献
266.
A Practical Approach to the Design, Operation, and Monitoring of In Situ Soil-Venting Systems 总被引:9,自引:0,他引:9
P.C. Johnson C.C. Stanley M.W. Kemblowski D.L. Byers J.D. Colthart 《Ground Water Monitoring & Remediation》1990,10(2):159-178
When operated properly, in situ soil venting or vapor extraction can be one of the most cost-effective remediation processes for soils contaminated with gasoline, solvents, or other relatively, volatile compounds. The components of soil-venting systems are typically off-the-shelf items, and the installation of wells and trenches can be done by reputable environmental firms. However, the design, operation, and monitoring of soil-venting systems are not trivial. In fact, choosing whether or not venting should be applied at a given site is a difficult decision in itself. If one decides to utilize venting, design criteria involving the number of wells, well spacing, well location, well construction, and vapor treatment systems must be addressed. A series of questions must be addressed to decide if venting is appropriate at a given site and to design cost-effective in situ soil-venting systems. This series of steps and questions forms a "decision tree" process. The development of this approach is an attempt to identify the limitations of in situ soil venting, and subjects or behavior that are currently difficult to quantify and for which future study is needed. 相似文献
267.
In an attempt to more fully understand the dissolved inorganic nitrogen dynamics of the Neuse River estuary, 15NH4 + and 15NO3 ? uptake rates were measured and daily depth-integrated rates calculated for seven stations distributed along the salinity gradient. Measurements were made at 2–3-wk intervals from March 1985 to February 1989. Significant dark NH4 + uptake occurred and varied both spatially and seasonally, accounting for as much as 95% of light uptake with the median being 33%. Apparent NH4 + uptake ranged from 0.001 μmol N 1?1 h?1 to 4.2 μmol N 1?1 h?1, with highest rates occurring during late summer-fall in the oligohaline estuary. Apparent NH4 + uptake was significantly related to NH4 + concentration (p<0.01); however, the regression explained <3% of the variation. Daily-integrated NH4 + uptake ranged from 0.1 mmol N m?2 d?1 to 133 mmol N m?2 d?1 and followed the trend of apparent uptake. Annual NH4 + uptake of the estuary was significantly lower in 1988 than for any other year. Dark uptake of NO3 ? was only 14% of maximum light uptake. Apparent NO3 ? uptake rates ranged from 0.001 μmol N 1?1 h?1 to 1.84 μmol N 1?1 h?1 with highest rates occurring in the oligohaline estuary. Apparent NO3 ? uptake was significantly related to NO3 ? concentration (p<0.01); however, the regression explained <5% of the variation. In general, NO3 ? uptake was only 20% of total dissolved inorganic nitrogen (DIN) uptake. Daily-integrated NO3 ? uptake ranged from 0.1 mmol N m?2 d?1 to 53 mmol N m?2 d?1 and followed similar patterns of apparent uptake. Annual NH4 + uptake was 11.39 mol N m?2 yr?1, 10.28 mol N m?2 Yr?1, 10.93 mol N m?2 yr?1, and 7.38 mol N m?2 yr?1, and 1.84 mol N m?2 yr?1, with the 4-yr mean being 10.0. Annual NO3 ? uptake was 3.12 mol N m?2 yr?1, 3.40 mol N m?2 yr?1, 1.96 mol N m?2 yr?1, and 1.84 mol N m?2 yr?1, with the 4-yr mean being 2.6. The total annual DIN uptake was more than twice published estimates of phytoplankton DIN demand, indicating that there is an important heterotrophic component of DIN uptake occurring in the water column. The extrapolation of nitrogen demand from primary productivity results in serious underestimates of estuarine nitrogen demand for the Neuse River estuary and may be true for other estuaries as well. 相似文献
268.
A statistical investigation is made of anticyclogenesis in the Mediterranean and European region during the period 1928 to 1937 inclusive; the distributions of anticyclogenesis in time and space are obtained and described.
With 7 Figures
This research was supported by the Geophysics Research Directorate of the U. S. Air Force Cambridge Research Center, under contract No. AF 19 (122)-466. 相似文献
Zusammenfassung Es wird eine statistische Untersuchung über die Bildung von Antizyklonen im Gebiet des Mittelmeers und Europas während der Periode 1928–1937 durchgeführt; dabei wird die zeitliche und räumliche Verteilung der Antizyklogenese abgeleitet und erörtert.
Résumé L'auteur soumet à un examen statistique la genèse des anticyclones qui se sont formés dans la région de la Méditerranée et de l'Europe de 1928 à 1937; par cette procédure il déduit et décrit l'anticyclogénèse dans le temps et l'espace.
With 7 Figures
This research was supported by the Geophysics Research Directorate of the U. S. Air Force Cambridge Research Center, under contract No. AF 19 (122)-466. 相似文献
269.
Neil C. Sturchio Stanley N. Williams Nestor P. Garcia Adela C. Londono 《Bulletin of Volcanology》1988,50(6):399-412
Hot springs and steam vents on the slopes of Nevado del Ruiz volcano provide evidence regarding the nature of hydrothermal activity within the summit and flanks of the volcano. At elevations below 3000 m, alkali-chloride water is discharged from two groups of boiling springs and several isolated warm springs on the western slope of Nevado del Ruiz. Chemical and isotopic geothermometers suggest that the boiling springs are fed by an aquifer having a subsurface equilibration temperature of at least 175°C, and the sampled warm spring is fed by an aquifer having a subsurface equilibration temperature near 150°C. Similarities in conservative solute ratios (e.g., B/Cl) indicate that the alkali-chloride waters may be related to a single reservoir at depth. Isotopic ratios of hydrogen and oxygen indicate that recharge for the alkali-chloride aquifers comes mostly from higher elevations on the volcano. Steam vents and steam-heated bicarbonate-sulfate springs at higher elevations, along a linear structural trend with the alkali-chloride springs, may be derived partly from the alkali-chloride water at depth by boiling. Steam from the vents (84°C) yields a gas geothermometer temperature of 209°C. Acid-sulfate-chloride and acid-sulfate waters are discharged widely from warm springs above 3000 m on the northern and eastern slopes of Nevado del Ruiz. Similarities in B/Cl and SO4/Cl ratios suggest that the acid waters are mixtures of water from an acid-sulfate-chloride reservoir with various proportions of shallow, dilute groundwater. The major source of sulfate, halogens, and acidity for the acid waters may be high-temperature magmatic gases. Available data on hot spring temperatures and compositions indicate that they have remained fairly stable since 1968. However, the eruption of November 13, 1985 apparently caused an increase in sulfate concentration in some of the acid springs that peaked about a year after the eruption. Long-term monitoring of hot spring compositions over many years will be required to better define the effects of volcanic activity on the Nevado del Ruiz hydrothermal system. 相似文献
270.
Stanley A. Mertzman Jr. 《Contributions to Mineralogy and Petrology》1978,67(3):261-265
The first occurrence of amphibole-bearing basalt in the southern Cascade volcanic province has been found in the Medicine
Lake area of California. Little Mount Hoffman, a late Pleistocene cinder and scoria cone, has erupted high-alumina olivine
tholeiite, the petrography of which yields a paragenetic phenocryst sequence of amphibole→olivine→plagioclase. The amphibole
is compositionally a tschermakite. Comparison with available experimental data indicates an initial depth of crystallization
somewhere between 40 and 100 km, temperature near 1000 °C, and f
O
2 near the Ni-NiO and QFM buffers.
Contribution No. 124 相似文献