Information systems playground—the target infrastructure     

Andrey N. Belikov  Fokke Dijkstra  Hans Gankema  Jeroen B. A. N. van Hoof  Rick Koopman 《Experimental Astronomy》2013,35(1-2):367-389

The Target infrastructure has been specially built as a storage and compute infrastructure for the information systems derived from Astro-WISE. This infrastructure will be used by several applications that collaborate in the area of information systems within the Target project. It currently consists of 10 PB of storage and thousands of computational cores. The infrastructure has been constructed based on the requirements of the applications. The storage is controlled by the Global Parallel File System of IBM. This file system takes care of the required flexibility by combining storage hardware with different characteristics into a single file system. It is also very scalable, which allows the system to be extended into the future, while replacing old hardware with new technology.  相似文献   

Improved expressions for the ellipsoidal harmonic series representing the Earth gravitational potential and its first and second derivatives on and outside the reference ellipsoid of revolution     

Margarita S. Petrovskaya  Andrey N. Vershkov 《Studia Geophysica et Geodaetica》2013,57(3):353-368

The Legendre functions of the second kind, renormalized by Jekeli, are considered in the external space on a set of ellipsoids of revolution which are confocal with respect to the normal ellipsoid. Among these ellipsoids a reference one is chosen which bounds the Earth. New expressions for the first and second order derivatives of the Legendre functions are derived. They depend on two very quickly convergent Gauss hypergeometric series which are obtained by transforming the slowly convergent initial hypergeometric series. The derived expressions are applied for constructing the ellipsoidal harmonic series for the Earth disturbing gravitational potential and its derivatives of the first and second orders. Since outside the chosen reference ellipsoid there are no Earth masses (as compared to the normal ellipsoid) then it is more appropriate for constructing the boundary-value equation and solving it on the basis of surface gravity data reduced to this ellipsoid.  相似文献   

Manifestation of the 2011 Great Tohoku Tsunami on the Coast of the Kuril Islands: A Tsunami with Ice     

Victor Kaistrenko  Nadezhda Razjigaeva  Andrey Kharlamov  Alexander Shishkin 《Pure and Applied Geophysics》2013,170(6-8):1103-1114

The tsunami generated by the 2011 Tohoku Earthquake (M _w = 9.0) reached maximum heights of about 5 m along the coast of the Kuril Islands. The most essential feature of this event was sea ice about 0.5 m thick moved by the ocean water. The tsunami did not cause any essential damage on the Kuril Islands, but significantly affected coastal zones and produced interesting effects. The problem of a tsunami accompanied by marine ice is discussed and illustrated with photos.  相似文献   

Event-based estimation of water budget components using a network of multi-sensor capacitance probes     

Andrey Guber 《水文科学杂志》2013,58(7):1227-1241

Abstract

A new approach was developed for estimating vertical soil water fluxes using soil water content time series data. Instead of a traditional fixed time interval, this approach utilizes the time interval between two sequential minima of the soil water storage time series to identify groundwater recharge events and calculate components of the soil water budget. We calculated water budget components: surface-water excess (Sw), infiltration less evapotranspiration (I – ET) and groundwater recharge (R) from May 2001 to January 2003 at eight locations at the USDA Agricultural Research Center, Beltsville, Maryland, USA. High uncertainty was observed for all budget components. This uncertainty was attributed to spatial and temporal variation in Sw, I – ET and R, and was caused by nonuniform rainfall distributions during recharge events, variability in the profile water content, and spatial variability in soil hydraulic properties. The proposed event-based approach allows estimating water budget components when profile water content monitoring data are available.

Citation Guber, A., Gish, T., Pachepsky, Y., McKee, L., Nicholson, T. & Cady, R. (2011) Event-based estimation of water budget components using a network of multi-sensor capacitance probes. Hydrol. Sci. J. 56(7), 1227–1241.  相似文献   

Quantifying spatiotemporal dynamics of agricultural landscapes using remotely sensed data and landscape metrics     

Andrey N. Petrov 《国际地球制图》2013,28(3):223-240

This study focuses on the spatiotemporal dynamics of agricultural lands and differences in rapidly developing urban and declining rural counties in Iowa, USA between 1984 and 2000. The study presents an analysis of land-cover maps derived from Landsat TM and ETM+ satellite imagery and different landscape metrics using FRAGSTATS and IDRISI software. The study provides evidence of both loss of croplands and change in fragmentation between 1984 and 2000. Fragmentation in agriculture-dominated areas increased with the development of urban centres and diversification of land uses. Fragmentation of landscapes, including agricultural land, was found to be higher in the urbanized counties, but was stable or even declined over time in these counties. In contrast, in the context of remote rural areas, agricultural landscapes experienced rapid increase in fragmentation and farmland loss. The urban–rural gradient analysis used in this study showed that the highest fragmentation occurred on the city edges. These findings suggest that farmland fragmentation is a complex process associated with socio-economic trends at regional and local scales. In addition, socio-economic determinants of landscape fragmentation differ between areas with diverging development trajectories. Intensive cropland fragmentation in remote agricultural regions, detected by this research, should be further studied and its possible effects on both agricultural productivity and biodiversity should be carefully considered.  相似文献   

Railroad bed bearing strength in the period of thawing and methods of its enhancement     

Andrey Petryaev  Anastasia Morozova 《寒旱区科学》2013,5(5):0548-0553

The practice of building and operating of railroad beds shows that the greatest at enuation of soils occurs in the spring, during their transition from the frozen to thawed state. The greatest influenc...  相似文献   

Structure of the Fram Strait branch of the boundary current in the Eurasian Basin of the Arctic Ocean     

Andrey V. Pnyushkov  Igor V. Polyakov  Vladimir V. Ivanov  Takashi Kikuchi 《Polar Science》2013,7(2):53-71

Recent mooring-based observations at several locations along the continental slope of the Arctic Ocean's Eurasian Basin showed a transformation of the Boundary Current (BC) from a mostly barotropic flow in Fram Strait to a jet-like baroclinic current northeast of Svalbard, and the reemergence of the barotropic structure of the flow in the eastern Eurasian Basin. This transformation is accompanied by a weakening of the flow from ～24 cm/s in Fram Strait to ～5 cm/s at the Lomonosov Ridge. The maximum of the baroclinic component of the BC at an intermediate depth (～200–370 m) is associated with the Atlantic Water core. The depth range of the baroclinic current maximum is controlled by cross-slope density gradients above and below the baroclinic velocity maximum as follows from the geostrophic balance of forces. According to the model simulations, the BC splits into shallow and deep branches in the proximity of Svalbard due to a divergence of isobaths, confirming topographically-controlled BC behavior. The shallow branch is located at a shelf break with a typical bottom depth of ～200 m and current speed of up to ～24 cm/s. The discussed results, which provide insight on some basic aspects of the dynamics of the BC (the major oceanic heat source for the Arctic Ocean), may be of importance for understanding of the ocean's role in shaping the arctic climate system state.  相似文献   

Landslide investigations in Russia and the former USSR     

Kazeev  Andrey  Postoev  German 《Natural Hazards》2016,86(1):81-105

The impact of natural hazards on mankind has increased dramatically over the past decades. Global urbanization processes and increasing spatial concentrations of exposed elements induce natural hazard risk at a uniquely high level. To mitigate affiliated perils requires detailed knowledge about elements at risk. Considering a high spatiotemporal variability of elements at risk, detailed information is costly in terms of both time and economic resources and therefore often incomplete, aggregated, or outdated. To alleviate these restrictions, the availability of very-high-resolution satellite images promotes accurate and detailed analysis of exposure over various spatial scales with large-area coverage. In the past, valuable approaches were proposed; however, the design of information extraction procedures with a high level of automatization remains challenging. In this paper, we uniquely combine remote sensing data and volunteered geographic information from the OpenStreetMap project (OSM) (i.e., freely accessible geospatial information compiled by volunteers) for a highly automated estimation of crucial exposure components (i.e., number of buildings and population) with a high level of spatial detail. To this purpose, we first obtain labeled training segments from the OSM data in conjunction with the satellite imagery. This allows for learning a supervised algorithmic model (i.e., rotation forest) in order to extract relevant thematic classes of land use/land cover (LULC) from the satellite imagery. Extracted information is jointly deployed with information from the OSM data to estimate the number of buildings with regression techniques (i.e., a multi-linear model from ordinary least-square optimization and a nonlinear support vector regression model are considered). Analogously, urban LULC information is used in conjunction with OSM data to spatially disaggregate population information. Experimental results were obtained for the city of Valparaíso in Chile. Thereby, we demonstrate the relevance of the approaches by estimating number of affected buildings and population referring to a historical tsunami event.

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Thermodynamic properties of H₄SiO₄ in the ideal gas state as evaluated from experimental data     

Andrey V. Plyasunov 《Geochimica et cosmochimica acta》2011,75(13):3853-3865

Solid phases of silicon dioxide react with water vapor with the formation of hydroxides and oxyhydroxides of silica. Recent transpiration and mass-spectrometric studies convincingly demonstrate that H₄SiO₄ is the predominant form of silica in vapor phase at water pressure in excess of 10⁻² MPa. Available literature transpiration and solubility data for the reactions of solid SiO₂ phases and low-density water, extending from 424 to 1661 K, are employed for the determination of Δ_fG⁰, Δ_fH⁰ and S⁰ of H₄SiO₄ in the ideal gas state at 298.15 K, 0.1 MPa. In total, there are 102 data points from seven literature sources. The resulting values of the thermodynamic functions of H₄SiO₄(g) are: Δ_fG⁰ = −1238.51 ± 3.0 kJ mol⁻¹, Δ_fH⁰ = −1340.68 ± 3.5 kJ mol⁻¹ and S⁰ = 347.78 ± 6.2 J K⁻¹ mol⁻¹. These values agree quantitatively with one set of ab initio calculations. The relatively large uncertainties are mainly due to conflicting data for H₄SiO₄(g) from various sources, and new determinations of would be helpful. The thermodynamic properties of this species, H₄SiO₄(g), are necessary for realistic modeling of silica transport in a low-density water phase. Applications of this analysis may include the processes of silicates condensation in the primordial solar nebula, the precipitation of silica in steam-rich geothermal systems and the corrosion of SiO₂-containing alloys and ceramics in moist environments.  相似文献   

Oxygen isotope heterogeneity of the mantle beneath the Canary Islands: insights from olivine phenocrysts     

Andrey A. Gurenko  Ilya N. Bindeman  Marc Chaussidon 《Contributions to Mineralogy and Petrology》2011,162(2):349-363

A relatively narrow range of oxygen isotopic ratios (?? ¹⁸O?=?5.0?C5.4??) is preserved in olivine of mantle xenoliths, mid-ocean ridge (MORB), and most ocean island basalts (OIB). The values in excess of this range are generally attributed either to the presence of a recycled component in the Earth??s mantle or to shallow level contamination processes. A viable way forward to trace source heterogeneity is to find a link between chemical (elemental and isotopic) composition of the earlier crystallized mineral phases (olivine) and the composition of their parental magmas, then using them to reconstruct the composition of source region. The Canary hotspot is one of a few that contains ~1- to 2-Ga-old recycled ocean crust that can be traced to the core-mantle boundary using seismic tomography and whose origin is attributed to the mixing of at least three main isotopically distinct mantle components i.e. HIMU, DMM, and EM. This work reports ion microprobe and single crystal laser fluorination oxygen isotope data of 148 olivine grains also analyzed for major and minor elements in the same spot. The olivines are from 20 samples resembling the most primitive shield stage picrite through alkali basalt to basanite series erupted on Gran Canaria, Tenerife, La Gomera, La Palma and El Hierro, Canary Islands, for which shallow level contamination processes were not recognized. A broad range of ?? ¹⁸O_olivine values from 4.6 to 6.1?? was obtained and explained by stable, long-term oxygen isotope heterogeneity of crystal cumulates present under different volcanoes. These cumulates are thought to have crystallized from mantle-derived magmas uncontaminated at crustal depth, representing oxygen isotope heterogeneity of source region. A relationship between Ni?×?FeO/MgO and ?? ¹⁸O_olivine values found in one basanitic lava erupted on El Hierro, the westernmost island of the Canary Archipelago, was used to estimate oxygen isotope compositions of partial melts presumably originated from peridotite (HIMU-type component inherited its radiogenic isotope composition from ancient, ~1 to 2?Ga, recycled ocean crust) and pyroxenite (young, <1?Ga, recycled oceanic crust preserved as eclogite with depleted MORB-type isotopic signature) components of the Canary plume. The model calculations yield 5.2 and 5.9?±?0.3?? for peridotite- and pyroxenite-derived melts, respectively, which appeared to correspond closely to the worldwide HIMU-type OIB and upper limit N-MORB ?? ¹⁸O values. This difference together with the broad range of ?? ¹⁸O variations found in the Canarian olivines cannot be explained by thermodynamic effects of oxygen isotopic fractionation and are believed to represent true variations in the mantle, due to oceanic crust and continental lithosphere recycling.  相似文献