Artificial Recharge and pollution of Ground Water     

Robert H. Harmeson  Orville W. Vogel 《Ground water》1963,1(1):11-15

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The dissociation constants of carbonic acid in seawater at salinities 5 to 45 and temperatures 0 to 45°C     

Rabindra N Roy  Lakshimi N Roy  Kathleen M Vogel  C Porter-Moore  Tara Pearson  Catherine E Good  Frank J Millero  Douglas M Campbell 《Marine Chemistry》1993,44(2-4)

The pK₁^* and pK₂^* for the dissociation of carbonic acid in seawater have been determined from 0 to 45°C and S = 5 to 45. The values of pK₁^* have been determined from emf measurements for the cell: where X is the mole fraction of CO₂ in the gas. The values of pK₂^* have been determined from emf measurements on the cell: The results have been fitted to the equations: where T is the temperature in K, S is the salinity, and the standard deviations of the fits are σ = 0.0048 in lnK₁^* and σ = 0.0070 in lnK₂^*.Our new results are in good agreement at S = 35 (±0.002 in pK₁^*and ±0.005 in pK₂^*) from 0 to 45°C with the earlier results of Goyet and Poisson (1989). Since our measurements are more precise than the earlier measurements due to the use of the Pt, H₂|AgCl, Ag electrode system, we feel that our equations should be used to calculate the components of the carbonate system in seawater.  相似文献   

Une approche innovante pour modéliser la biodégradation des composés organochlorés volatils en aquifères poreux     

Fabien Nex  Gerhard Schäfer  Jean-Marie Côme  Timothy M. Vogel 《Comptes Rendus Geoscience》2006,338(5):297-306

The goal of this study was to develop an innovative chloroethene biodegradation module based on biological, thermodynamical and mechanistic concepts. The biodegradation scheme was based on the postulate that in each part of an aquifer only one degradation mechanism is dominant: the one involving the most energetic electron acceptor. Thus, the selection of the active degradation mechanism was a function of the concentration of different electron acceptors. Modified Monod-type kinetics was used in order to take into account the possible influence of some compounds on the biodegradation of a given organic compound. The numerical model developed was applied to a simple test case, whose results are presented here. To cite this article: F. Nex et al., C. R. Geoscience 338 (2006).  相似文献   

Geochemistry of silicic magmas in the Macolod Corridor, SW Luzon, Philippines: evidence of distinct, mantle-derived, crustal sources for silicic magmas     

Thomas A. Vogel  Timothy P. Flood  Lina C. Patino  Melissa S. Wilmot  Raymond Patrick R. Maximo  Carmencita B. Arpa  Carlo A. Arcilla  James A. Stimac 《Contributions to Mineralogy and Petrology》2006,151(3):267-281

Silicic volcanic deposits (>65 wt% SiO₂), which occur as domes, lavas and pyroclastic deposits, are relatively abundant in the Macolod Corridor, SW Luzon, Philippines. At Makiling stratovolcano, silicic domes occur along the margins of the volcano and are chemically similar to the silicic lavas that comprise part of the volcano. Pyroclastic flows are associated with the Laguna de Bay Caldera and these are chemically distinct from the domes and lavas at Makiling stratovolcano. As a whole, samples from the Laguna de Bay Caldera contain lower concentrations of MgO and higher concentrations of Fe₂O_3(t) than the samples from domes and lavas. The Laguna de Bay samples are more enriched in incompatible trace elements. The silicic rocks from the domes, Makiling Volcano and Laguna de Bay Caldera all contain high alkalis and high K₂O/Na₂O ratios. Melting experiments of primitive basalts and andesites demonstrate that it is difficult to produce high K₂O/Na₂O silicic magmas by fractional crystallization or partial melting of a low K₂O/Na₂O source. However, recent melting experiments (Sisson et al., Contrib Mineral Petrol 148:635–661, 2005) demonstrate that extreme fractional crystallization or partial melting of K-rich basalts can produce these silicic magmas. Our model for the generation of the silicic magmas in the Macolod Corridor requires partial melting of mantle-derived, evolved, moderate to K-rich, crystallized calc-alkaline magmas that ponded and crystallized in the mid-crust. Major and trace element variations, along with oxygen isotopes and ages of the deposits, are consistent with this model. Electronic Supplementary Material Supplementary material is available for this article at  相似文献   

A Holocene high-resolution record of aquatic productivity,seasonal anoxia and meromixis from varved sediments of Lake Łazduny,North-Eastern Poland: insight from a novel multi-proxy approach     

Andrea Sanchini  Sönke Szidat  Wojciech Tylmann  Hendrik Vogel  Agnieszka Wacnik  Martin Grosjean 《第四纪科学杂志》2020,35(8):1070-1080

Anthropogenic eutrophication and spreading anoxia in freshwater systems is a global concern. Little is known about anoxia in earlier historic times under weaker human impact, or under prehistoric natural conditions with different trophic, land cover and climatic regimes. We use a novel approach that combines high-resolution hyperspectral imaging with µ-XRF and HPLC-pigment data, which allows us to assess chloropigments (productivity) and bacteriopigments (anoxia) at seasonal subvarve-scale resolution. Our ~9700 cal a bp varved sediment record from NE Poland suggests that productivity increased stepwise from oligotrophic Early Holocene conditions (until ~9200 cal a bp ) to mesotrophic conditions in the Mid- and Late Holocene. Natural eutrophication was mainly a function of progressing landscape evolution with intense weathering under dense forest and warm-moist climatic conditions. Generally, anoxia increased with increasing productivity. Seasonal anoxia and some multi-decadal periods of meromixis were the common mixing patterns throughout the Holocene except for a period of persisting meromixis between ~5200 and 2000 cal a bp. Anthropogenic deforestation around 400 cal a bp resulted in substantially better lake oxygenation despite high productivity. In this small lake, aquatic productivity and lakeshore forest cover (wind shield) were more important factors controlling oxic/anoxic conditions than Holocene temperature variability.  相似文献   

Disaster risk profiling in southern Africa: inventories,impacts and implications     

Jan de Waal  Coleen Vogel 《Natural Hazards》2016,84(3):1921-1942

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Flooding a landscape: impact of Holocene transgression on coastal sedimentology and underwater archaeology in Kiladha Bay (Greece)     

Morgane Surdez  Julien Beck  Dimitris Sakellariou  Hendrik Vogel  Patrizia Birchler Emery  Despina Koutsoumba  Flavio S. Anselmetti 《Swiss Journal of Geoscience》2018,111(3):573-588

Franchthi Cave, bordering Kiladha Bay, in Greece, is a key archaeological site, due to its long occupation time, from?~?40,000 to?~?5000 year BP. To date, no clear evidence of Neolithic human dwellings in the cave was found, supporting the assumption that Neolithic people may have built a village where there is now Kiladha Bay. During the Neolithic period/Early Holocene, wide areas of the bay were indeed emerged above sea level. Bathymetric and seismic data identified a terrace incised by a valley in?~?1 to 2 m sediment depth. Eight sediment cores, up to 6.3-m-long, were retrieved and analysed using petrophysical, sedimentological, geochemical, and chronostratigraphic methods. The longest core extends into the exposure surface, consisting of a layer of carbonate rubble in a finer matrix, representing weathering processes. Dated organic remains place this unit at?~?8500 cal year BP. It is overlain by stiff silty mud representing an estuarine environment. This mud is capped by reduced sediments with roots marking an exposure surface. A shell-layer, dated to?~?6300 cal year BP, overlies this terrestrial sequence, reflecting the marine transgression. This layer occurs at 10.8 mbsl, 7.7 m deeper than the global sea level at that time, suggesting tectonic subsidence in the area. It is overlain by finer-grained marine carbonate-rich sediments. The top of the core shows traces of eutrophication, pebbles and marine shells, all likely a result of modern anthropogenic processes. These results are interpreted in the context of human occupation: the exposed surface contains pottery sherds, one dating to the Early to Middle Neolithic period, indicating that Neolithic people were present in this dynamic landscape interacting with a migrating coastline. Even if the artefacts are isolated, future investigations of the submerged landscape off Franchthi Cave might lead to the discovery of a Neolithic village, which eventually became buried under marine sediments.  相似文献   

Dimensions of drought: South African case studies   总被引：1，自引：0，他引：1  

C. H. Vogel  J. H. Drummond 《GeoJournal》1993,30(1):93-98

The recent drought in southern Africa has underscored the need for detailed analysis of the phenomenon. While geographers have researched the causes and impacts of drought in many African contexts, South Africa and in particular its Bantustans have not received sufficient similar attention. This paper outlines firstly the dimensions of drought in South Africa, including the biophysical and socio-economic factors. Issues such as land-use management, drought planning and relief are interrogated in the South African context. The final section of the paper highlights these debates with specific reference to case studies of past and present drought initiatives in South Africa.  相似文献   

Contamination des sédiments superficiels des principales rivières du Canton de Genève par les Polychlorobiphényles et DDT     

Dr. Par Cl. Corvi  Dr. J. Vogel 《Aquatic Sciences - Research Across Boundaries》1985,47(1):12-20

The concentrations of PCBs and DDT at the surface of sediments of rivers in the Canton of Geneva were examined. Concentration variations observed along the rivers are discussed. In the case of the Rhône River, recent pollution at the surface of sediments is compared with that of aged underlying layers.  相似文献   

Magma mixing: the Marsco suite,Isle of Skye,Scotland     

Thomas A. Vogel  Leland W. Younker  John T. Wilband  Elaine Kampmueller 《Contributions to Mineralogy and Petrology》1984,87(3):231-241

Magma mixing has been proposed as a major mechanism for the origin of a wide variety of rock suites. In mid-ocean basalts there are few obstacles to mixing because of the similarities in chemical and physical properties of the proposed end-members. However, in calc-alkaline rocks the proposed end-members have disparate properties and these present obstacles to mixing.The Marsco suite is ideal to evaluate the process of magma mixing because it is considered to be a classic example of magma mixing of diverse magma types and because compositionally diverse, coexisting liquids were present throughout the area.The results of this study are that the chemical data for the Marsco suite fit a mixing model remarkably well and that the mixing did not take place at the present level of exposure. The Marsco mixed suite is similar to the experiments of Kouchi and Sunagawa (1982, 1983) in which mixing was produced by forced convection. Based on the Marsco suite, a similar occurrence in Ardnamurchan, and the experimental data, we conclude that mixing was dominated by mechanical mixing and this mechanical mixing was efficient enough to allow diffusional processes to homogenize the liquids.It is postulated that injection of mafic magma into the base of a silicic magma system leads to mixing and mobilization of the system. The mechanical interaction that produces the mixing also leads to disruption of the system. Liquids involved with the mixing process at depth are mobilized and coexist at shallower levels.  相似文献