Spatial inference with an interchangeable rule format

Rule interchange between information systems is expanding as new interoperable rule formats are emerging from research. However, existing spatial inference systems generally operate on locally stored data with an internal rule format. Consequently, their design offers little support or facilities for rule interchange. This article presents the requirements, components and design for a spatial inference system with rule interchange. Computational efficiency and overall functionality of the design are considered separately, with the latter demonstrated using encoded agricultural legislation and data. A spatial inference system with rule interchange is based on three primary components: rule representation, spatial functionality and data integration. Of these, the interoperable rule representation and data integration distinctly differ from existing spatial inference systems. The presented inference system combines a spatial superset of the W3C Rule Interchange Format (RIF) with full Open Geospatial Consortium simple feature access (OGC SFA) functionality and on-demand data integration utilising Resource Deception Framework (RDF). The design was found to be effective with a computational efficiency depending predominantly on the spatial operations. This design could be further adapted to implement spatial extensions for existing inference systems. Considerable benefits were also discovered when RIF was used as the native language for the inference engine, thereby removing the need for rule transformations and facilitating on-demand data integration with the GML.     

Timescales of disequilibrium melting in the crust: constraints from modelling the distribution of multiple trace elements and a case study from the Lesser Himalayan rocks of Sikkim

A numerical code has been developed to track the distribution of trace elements in crustal rocks undergoing melting. The model handles diffusion with moving boundaries and accounts for the processes of diffusion, dissolution and precipitation in a partially molten system. Among the various input parameters for modelling, source composition (i.e. modal abundance) variations, diffusion coefficients and partition coefficients are found to exert a significant control on the melt chemistry. The other inputs such as melt reaction stoichiometry, kinetics of melting and grain size of protolith have lesser influence. Exploration of the general behaviour indicates that for systems in which disequilibrium melting of the kind considered in this paper occurs, trace element concentrations may be used to constrain the composition of the protolith or the timescales of melting, depending on the specific circumstances. After exploring some general features of melting in a pelitic system, the model is applied to calculate trace element distributions in migmatites from the Lesser Himalayan rocks in Sikkim, India. We focus on the distribution of trace elements during the initial stages of melt formation. These partially molten rocks show disequilibrium distribution of trace elements, and the numerical code is capable of quantitatively reproducing many of the observed patterns. The results of the modelling indicate that the observed melts in this zone were formed within 50,000 years and that segregation of melts (into leucosome and restite) was complete between 50,000 and 250,000 years. These short timescales may point to deformation-enhanced melt segregation at least on a hand specimen scale. It is important to distinguish between timescales of segregation over these scales and timescales of removal of melt on an outcrop scale to form plutons—the latter, requiring higher degrees of melting and larger distances of migration, take longer.     

Characteristics and mechanism of the landslide in Yongguang village,Minxian County,China

Natural Hazards - More than 2330 landslides/mudflows in loess were triggered by the 2013 Minxian earthquake (MS 6.6) in its epicentral area in Minxian County, Gansu, China. A comprehensive...     

Geochemical evolution of Jurassic diorites from the Bristol Lake region,California, USA,and the role of assimilation

Late Jurassic dioritic plutons from the Bristol Lake region of the eastern Mojave Desert share several geochemical attributes with high-alumina basalts, continental hawaiite basalts, and high-K are andesites including: high K₂O concentrations; high Al₂O₃ (16–19 weight %); elevated Zr/TiO₂; LREE (light-rare-earth-element) enrichment (La/Yb_CN=6.3–13.3); and high Nb. Pearce element ratio analysis supported by petrographic relations demonstrates that P, Hf, and Zr were conserved during differentiation. Abundances of conserved elements suggest that dioritic plutons from neighboring ranges were derived from similar parental melts. In the most voluminous suite, correlated variations in elemental concentrations and (⁸⁷Sr/⁸⁶Sr)_i indicate differentiation by fractional crystallization of hornblende and plagioclase combined with assimilation of a component characterized by abundant radiogenic Sr. Levenberg-Marquardt and Monte Carlo techniques were used to obtain optimal solutions to non-linear inverse models for fractional crystallization-assimilation processes. Results show that the assimilated material was chemically analogous to lower crustal mafic granulites and that the mass ratio of contaminant to parental magma was on the order of 0.1. Lack of enrichment in ¹⁸O with differentiation is consistent with the model results. Elemental concentrations and O, Sr, and Nd isotopic data point to a hydrous REE-enriched subcontinental lithospheric source similar to that which produced some Cenozoic continental hawaiites from the southern Cordillera. Isotopic compositions of associated granitoids suggest that partial melting of this subcontinental lithosphere may have been an important process in the development of the Late Jurassic plutonic arc of the eastern Mojave Desert.     

Soil respiration under three different land use types in a tropical mountain region of China

Soil respiration (SR) Wis one of the largest contributors of terrestrial CO_2 to the atmosphere.Environmental as well as physicochemical parameters influence SR and thus, different land use practices impact the emissions of soil CO_2. In this study, we measured SR, bi-monthly, over a one-year period in a terrace tea plantation, a forest tea plantation and a secondary forest, in a subtropical mountain area in Xishuangbanna, China. Along with the measurement of SR rates, soil characteristics for each of the land use systems were investigated. Soil respiration rates in the different land use systems did not differ significantly during the dry season, ranging from2.7±0.2 μmol m~(-2) s~(-1) to 2.8±0.2 μmol m~(-2) s~(-1). During the wet season, however, SR rates were significantly larger in the terrace tea plantation(5.4±0.5 μmol m~(-2)s~(-1)) and secondary forest(4.9±0.4 μmol m~(-2)s~(-1)) than in the forest tea plantation(3.7±0.2 μmol m~(-2) s~(-1)).This resulted in significantly larger annual soil CO_2 emissions from the terrace tea and secondary forest,than from the forest tea plantation. It is likely that these differences in the SR rates are due to the 0.5times lower soil organic carbon concentrations in thetop mineral soil in the forest tea plantation, compared to the terrace tea plantation and secondary forest.Furthermore, we suggest that the lower sensitivity to temperature variation in the forest tea soil is a result of the lower soil organic carbon concentrations. The higher SR rates in the terrace tea plantation were partly due to weeding events, which caused CO_2 emission peaks that contributed almost 10% to the annual CO_2 flux. Our findings suggest that moving away from heavily managed tea plantations towards low-input forest tea can reduce the soil CO_2 emissions from these systems. However, our study is a casestudy and further investigations and upscaling are necessary to show if these findings hold true at a landscape level.     

Smithsonian Institution’s Global Volcanism Network

Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network, v. 29, no. 1, January 2004 (on the Internet at ). Edited by scientists at the Smithsonian, this Bulletin includes reports provided by a worldwide network of correspondents. The reports contain the names and contact information for all sources. Please note that these reports are preliminary and subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism, seismic unrest, monitoring data, and field observations.     

Smithsonian Institution's Global Volcanism Network

Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network, vol. 30, no. 3, March 2005 (on the Internet at ). Edited by scientists at the Smithsonian, this Bulletin includes reports provided by a worldwide network of correspondents. The reports contain the names and contact information for all sources. Please note that these reports are preliminary and subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism, seismic unrest, monitoring data, and field observations.     

Smithsonian Institution’s Global Volcanism Network

Information included in this summary is based on more detailed reports published in the Bulletin of the Global Volcanism Network, vol. 29, no. 12, December 2004 (on the Internet at ). Edited by scientists at the Smithsonian, this Bulletin includes reports provided by a worldwide network of correspondents. The reports contain the names and contact information for all sources. Please note that these reports are preliminary and subject to change as events are studied in more detail. The Global Volcanism Program welcomes further reports of current volcanism, seismic unrest, monitoring data, and field observations.     

Multi-spectroscopic study of Fe(II) in silicate glasses: Implications for the coordination environment of Fe(II) in silicate melts

The coordination environment of Fe(II) has been examined in seven anhydrous ferrosilicate glasses at 298 K and 1 bar using ⁵⁷Fe Mössbauer, Fe K-edge X-ray near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS), UV-Vis-NIR, and magnetic circular dichroism (MCD) spectroscopies. Glasses of the following compositions were synthesized from oxide melts (abbreviation and nonbridging oxygen:tetrahedral cation ratio (NBO/T) in parentheses): Li₂FeSi₃O₈ (LI2: 1.33), Rb₂FeSi₃O₈ (RB2: 1.33), Na_l.08Fe_l.l7Si_3.l3O₈ (NAl: 1.09), Na_l.46Ca_0.24Fe_l.08Si_2.97O₈ (NC6: 1.38), Na_l.09Ca_0.51Fe_0.72Si_3.10O₈ (NC2: 1.15), Na_0.99Ca_0.92Fe_0.24 Si_3.17O₈ (NCl: 1.04), and Na_0.29Mg_0.53Ca_0.52Fe_0.56Al_0.91Si_2.44O₈ (BAS: 1.05). Mössbauer, XANES, and EXAFS information suggests that iron is dominantly ferrous in all glasses (<10 atom% Fe(III)) with an average first-neighbor Fe(II) coordination varying from ∼ 4 to 5.2 (±0.2) oxygens. The UV-Vis-NIR spectrum of each sample exhibits intense absorption centered near 8100-9200 cm⁻¹ and weak absorption near 5000 cm^−l, which cannot be assigned unambiguously. The MCD spectrum of NC6 glass, which is the first such measurement on a silicate glass, shows three transitions at ∼8500 cm⁻¹, ∼6700 cm⁻¹, and ∼4500 cm⁻¹. The behavior of these MCD bands as a function of temperature (1.6 K to 300 K) and magnetic field strength (1 T to 7 T) indicates that they most likely arise from three distinct Fe(II) sites with different ground states, two of which are 5-coordinated and one of which is 4-coordinated by oxygens.The combined results suggest that Fe(II) predominantly occupies 5- and 4-coordinated sites in each glass, with the ratios differing for the different compositions. Small amounts of 6-coordinated Fe(II) are possible as well, but primarily in the more basic glass compositions such as BAS. The substitution of Li(I) for Rb(I) in the M₂FeSi₃O₈ base glass composition causes a weakening of the average Fe(II)-O bond, as indicated by the longer Fe(II)-O distance in the latter. The basalt composition glass was found to have the largest Fe(II) sites relative to those in the other glasses in this study. A bond valence model that helps predict the coordination number of Fe(II) in silicate glasses is proposed. The structural information extrapolated to Fe(II)-bearing melts is parameterized using bond valence theory, which helps to rationalize the melt-crystal partitioning behavior of ferrous iron in natural and synthetic melt-crystal systems.