Dynamic implications of ridges on a debris avalanche deposit at Tutupaca volcano (southern Peru)     

Patricio Valderrama  Olivier Roche  Pablo Samaniego  Benjamin van Wyk de Vries  Karine Bernard  Jersy Mariño 《Bulletin of Volcanology》2016,78(2):14

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Comparison of two gas-phase chemical kinetic mechanisms of ozone formation over Europe     

Youngseob Kim  Karine Sartelet  Christian Seigneur 《Journal of Atmospheric Chemistry》2009,62(2):89-119

Two recent gas-phase chemical kinetic mechanisms for tropospheric ozone formation, one based on the lumped-structure approach (CB05) and the other based on the lumped-molecule approach (RACM2), are compared for simulations of ozone over Europe. The host air quality model is POLAIR3D of the Polyphemus modeling platform. A one-month period (15 July to 15 August 2001) is simulated. Model performance is satisfactory with both mechanisms. Overall, the two mechanisms give similar results with a domain-averaged difference of 3 ppb and a mean fractional absolute difference of 5% (values averaged over the month for the daily 8-h average maximum ozone concentrations). This difference results from different treatments in the two mechanisms for both inorganic and organic chemistry. Differences in the treatment of the inorganic chemistry are due mainly to differences in the kinetics of two reactions: NO + O₃ \(\longrightarrow\) NO₂ + O₂ and NO + HO₂ \(\longrightarrow\) NO₂ + OH. These differences lead to a domain-averaged difference in ozone concentration of 5%, with RACM2 kinetics being more conducive to ozone formation. Differences in the treatment of organic chemistry lead to a domain-averaged difference in ozone concentration of 3%, with CB05 chemistry being more conducive to ozone formation. This average difference results in part from compensating effects among various VOC classes and some significant differences are identified at specific locations (the coastline of northern Africa and eastern Europe: 9%) and for specific organic classes (aldehydes, biogenic alkenes and aromatics). Differences in the treatment of the organic chemistry result from various aspects. For some VOC classes, such as aldehydes and biogenic alkenes, the more detailed explicit treatments using more model species in RACM2 lead to either greater or lower reactivity depending on the assumptions made for the oxidation products. For other VOC species, such as aromatics, the assumptions made about the major chemical oxidation pathways (aromatic alcohol formation in CB05 vs. ring opening in RACM2) affect the ozone formation significantly. Reconciliation of different chemical kinetic mechanisms will require experimental data to reduce current uncertainties in the kinetic (e.g., NO oxidation) and mechanistic (e.g., aromatics oxidation) representations of major chemical pathways.  相似文献   

Louvain-la-Neuve,Belgium, from campus to new town     

Jacques Charlier 《GeoJournal》1977,1(4):47-55

Summary Louvain-la-Neuve, the sole Belgian New Town in three centuries, is located about thirty kilometers southwards of Brussels. In its first stage it had been established for welcoming most of the faculties of the Catholic University of Louvain (C. U. L.), which transferred from the original location in Louvain. The estate acquired by the C. U. L. mainly covers an agricultural area of 900 hectares, partly divided into 338 hectares for the future urbanized perimeter, 180 hectares for a public forest, and 163 hectares for a scientific park, designed for private research and development activities in connection with academic laboratories.The first part of the city center is almost completed and is located in the dale of the Malaise, on a substructure with underground parking and a railway station. Four neighbourhood units have been planned on the top of the slopes; the first two are already nearly finished and a third is under way. The principle of segregation of automobile and pedestrian traffic and its advanced architectural style constitute the main features.The active population of Louvain-la-Neuve now reaches about 12,000 (two-thirds are the students of the C. U. L.), and the residential population numbers more than 6,000 inhabitants (three-quarters are students and their families). The age structure is very young, due to the high proportion of students.Commuting to Louvain-la-Neuve is facilitated by excellent road and public transportation connections. As time goes by, it is anticipated that commuting will diminish. Moreover, a phenomenon of external commuting is developing. The attractive sphere and environment, the pedestrian areas and the emphyteotic system are the key features of the future residential development for persons neither professionally linked to the C. U. L. nor to the New Town.When the student transference is completed in 1979, the stage of real diversification of activities and functions will begin. About 20,000 inhabitants are scheduled for location by 1985 and a maximum of 50,000 by the end of the century. At that time, Louvain-la-Neuve together with its neighbours, Wavre and Ottignies, will form an urban tripole on a regional level, thereby strengthening the urban framework of the Walloon Brabant.  相似文献   

Influence de la microporosité sur le piégeage du gaz dans un milieu poreux naturel     

Karine Suzanne  Joël Billiotte 《Comptes Rendus Geoscience》2004,336(12):1071-1078

Trapped-gas content in natural porous media, also called residual gas saturation (Sgr), corresponds to the imbibition end-point. To define the parameters controlling Sgr, two parameters were studied: the influence of rock characteristics (on 400 sandstone samples) and initial gas saturation (Sgi), on the basis of 60 experimental curves between Sgr and Sgi. Based on an extensive experimental database, this study establishes the dominant influence of microporosity on trapped gas saturation, and indirectly that of the contained clays. To cite this article: K. Suzanne, J. Billiotte, C. R. Geoscience 336 (2004).  相似文献   

The Fedorivka layered intrusion (Korosten Pluton, Ukraine): An example of highly differentiated ferrobasaltic evolution   总被引：1，自引：0，他引：1  

J.C. Duchesne  L. Shumlyanskyy  B. Charlier 《Lithos》2006,89(3-4):353-376

This study documents the petrography and whole-rock major and trace element geochemistry of 38 samples mainly from a drill core through the entire Fedorivka layered intrusion (Korosten Pluton), as well as mineral compositions (microprobe analyses and separated mineral fraction analyses of plagioclase, ilmenite, magnetite and apatite) of 10 samples. The Fedorivka layered intrusion can be divided into 4 lithostratigraphic units: a Lower Zone (LZ, 72 m thick), a Main Zone (MZ, 160 m thick), and an Upper Border Zone, itself subdivided into 2 sub-zones (UBZ₂, 40 m thick; UBZ₁, 50 m thick). Igneous lamination defines the cumulate texture, but primary cumulus minerals have been affected by trapped liquid crystallization and subsolidus recrystallization. The dominant cumulus assemblage in MZ and UBZ₂ is andesine (An_39–42), iron-rich olivine (Fo_32–42), augite (En_29–35Fs_24–29Wo_42–44), ilmenite (Hem_1–6), Ti-magnetite (Usp_52–78), and apatite. The data reveal a continuous evolution from the floor of the intrusion (LZ) to the top of MZ, due to fractional crystallization, and an inverse evolution in UBZ, resulting from crystallization downwards from the roof. The whole-rock Fe/Mg ratio and incompatible element contents (e.g. Rb, Nb, Zr, REE) increase in the fractionating magma, whereas compatible elements (e.g. V, Cr) steadily decrease. The intercumulus melt remained trapped in the UBZ cumulates due to rapid cooling and lack of compaction, and cumulus mineral compositions re-equilibrated (e.g. olivine, Fe–Ti oxides). In LZ, the intercumulus melt was able to partially or totally escape. The major element composition of the MZ cumulates can be approximated by a mixing (linear) relationship between a plagioclase pole and a mafic pole, the latter being made up of all mafic minerals in (nearly) constant relative proportions. By analogy with the ferrobasaltic/jotunitic liquid line of descent, defined in Rogaland, S. Norway, and its conjugated cumulates occurring in the Transition Zone of the Bjerkreim-Sokndal intrusion (Rogaland, a monzonitic (57% SiO₂) melt is inferred to be in equilibrium with the MZ cumulates. The conjugated cumulate composition falls (within error) on the locus of cotectic compositions fixed by the 2-pole linear relationship. Ulvöspinel is the only Ti phase in some magnetites that have been protected from oxidation. QUIlF equilibria in these samples show that magnetite and olivine in MZ have retained their liquidus compositions during subsolidus cooling. This permits calculation of liquidus fO₂ conditions, which vary during fractionation from ΔFMQ = 0.7 to − 1.4 log units. Low fO₂ values are also evidenced by the late appearance of cumulus magnetite (Fo₄₂) and the high V³⁺-content of the melt, reflected in the high V-content of the first liquidus magnetite (up to 1.85% V).  相似文献   

Numerical quantification of sources and phase partitioning of chemical species in cloud: application to wintertime anthropogenic air masses at the Puy de Dôme station     

Maud Leriche  R. Lyana Curier  Laurent Deguillaume  Dimitri Caro  Karine Sellegri  Nadine Chaumerliac 《Journal of Atmospheric Chemistry》2007,57(3):281-297

The Model of Multiphase Cloud Chemistry M2C2 has recently been extended to account for nucleation scavenging of aerosol particles in the cloud water chemical composition. This extended version has been applied to multiphase measurements available at the Puy de Dôme station for typical wintertime anthropogenic air masses. The simulated ion concentrations in cloud water are in reasonable agreement with the experimental data. The analysis of the sources of the chemical species in cloud water shows an important contribution from nucleation scavenging of particles which prevails for nitrate, sulphate and ammonium. Moreover, the simulation shows that iron, which comes only from the dissolution of aerosol particles in cloud water, has a significant contribution in the hydroxyl radical production. Finally, the simulated phase partitioning of chemical species in cloud are compared with measurements. Numerical results show an underestimation of interstitial particulate phase fraction with respect to the measurements, which could be due to an overestimation of activated mass by the model. However, the simulated number scavenging efficiency of particles agrees well with the measured value of 40% of total number of aerosol particles activated in cloud droplets. Concerning the origin of chemical species in cloud water, the model reproduces quite well the contribution of gas and aerosol scavenging estimated from measurements. In addition, the simulation provides the contribution of in-cloud chemical reactivity to cloud water concentrations.  相似文献   

Territory and territorial transformation: the rural properties of the Dávalos-Bracamontes family in the Compostela region (Seventeenth Century)     

Vizcaíno-Monroy  Liliana J.  Lefebvre  Karine  Urquijo-Torres  Pedro S. 《GeoJournal》2021,86(4):1817-1834

This investigation seeks to analyse the territorial transformations, land uses, and land tenures in the region of Compostela, Nueva Galicia during the seventeenth century, using land grants for sites of cattle and sheep husbandry and farmland granted as the rural properties to the Dávalos-Bracamontes family, who in 1690 obtained the title of the Counts of Miravalle. The novohispanas haciendas served as territorial control mechanisms of the use and incorporation of new forms of exploitation of the area’s natural resources. The methodology is based on the analysis of the archival data, historical cartography, supplemented by information collected in fieldwork and use of historical modality of geographic information systems. The haciendas of La Lagunilla, Miravalle and San José were located and together represented 33,736.60 ha of land for livestock and agriculture. The territorial extension was possible due to the disappearance of villages, parse indigenous populations in the surroundings and commitments made by the Spanish Crown to the Dávalos-Bracamontes family.

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BRAMS model performance for significant event involving Brazilian platform ship     

Rodrigues  Karine dos Santos  do Carmo  Luiz Felipe Rodrigues  Palmeira  Ana Cristina Pinto de Almeida  Andrioni  Marcelo 《Natural Hazards》2022,110(3):2277-2302

Natural Hazards - After a storm displaced the P-70 platform ship located in Guanabara Bay to the coast on January 30, 2020, a numerical investigation was carried out with the BRAMS (Brazilian...  相似文献   

The abundance and isotopic composition of water in eucrites          下载免费PDF全文

T. J. Barrett  J. J. Barnes  R. Tartèse  M. Anand  I. A. Franchi  R. C. Greenwood  B. L. A. Charlier  M. M. Grady 《Meteoritics & planetary science》2016,51(6):1110-1124

Volatile elements play a key role in the dynamics of planetary evolution. Extensive work has been carried out to determine the abundance, distribution, and source(s) of volatiles in planetary bodies such as the Earth, Moon, and Mars. A recent study showed that the water in apatite from eucrites has similar hydrogen isotopic compositions compared to water in terrestrial rocks and carbonaceous chondrites, suggesting that water accreted very early in the inner solar system given the ancient crystallization ages (~4.5 Ga) of eucrites. Here, the measurements of water (reported as equivalent H₂O abundances) and the hydrogen isotopic composition (δD) of apatite from five basaltic eucrites and one cumulate eucrite are reported. Apatite H₂O abundances range from ~30 to ~3500 ppm and are associated with a weighted average δD value of ?34 ± 67‰. No systematic variations or correlations are observed in H₂O abundance or δD value with eucrite geochemical trend or metamorphic grade. These results extend the range of previously published hydrogen isotope data for eucrites and confirm the striking homogeneity in the H‐isotopic composition of water in eucrites, which is consistent with a common source for water in the inner solar system.  相似文献   

U–Pb dating of zircon in hydrothermally altered rocks as a correlation tool: Application to the Mangakino geothermal field,New Zealand     

C.J.N. Wilson  B.L.A. Charlier  C.J. Fagan  K.D. Spinks  D.M. Gravley  S.F. Simmons  P.R.L. Browne 《Journal of Volcanology and Geothermal Research》2008

Recognition and correlation of rock units within geothermal fields is often hampered by high degrees of alteration that obscure primary mineralogies and lithological boundaries, and preclude direct dating by radiometric techniques. Magmatic zircons are commonly present in silicic volcanic rocks, where zircon saturation was achieved and zircons crystallized up to the point of eruption. Young zircons are highly resistant to hydrothermal alteration and can yield a record of their crystallization ages in otherwise heavily altered rocks. Zircon crystallization-age spectra have been obtained by SIMS techniques (SHRIMP-RG) from three samples of cuttings and a core sample from ignimbrite penetrated in 3 drillholes up to ~ 3.2 km deep at the Mangakino geothermal field in New Zealand. The crystallization ages are similar between the drillcore and cutting samples, indicating that downhole mixing of cuttings has not been important, and showing collectively that volcanic units of closely similar ages are represented between ~ 1.4 and ~ 3.2 km depth. This is despite apparent changes in the inferred primary volcanic lithology that had led to earlier inferences that multiple ignimbrites of contrasting age were present in this depth interval. Comparisons of zircon crystallization-age spectra and inferred primary mineralogical characteristics from the drillhole samples with surficial ignimbrites that crop out west of Mangakino suggest that the boreholes have entered a > 1.8-km-thick intracaldera fill of ignimbrite generated in the closely-spaced Kidnappers and Rocky Hill eruptions at ~ 1 Ma.  相似文献